In the prewar set, there are unstable parapets and spalling concrete.
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However, the penetration hole of Panzerfaust warheads was larger, while shockwave within the target material, frontal spalling, and blast were greater.
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When such bubbles collapse, a localized high pressure can cause spalling on adjacent surfaces.
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However, interior sealers are good for preventing high atmospheric humidity inside the basement from absorbing into the porous masonry and causing spalling. Spalling is a condition where constant high humidity or moisture breaks down masonry surfaces, causing deterioration and shedding of the concrete surfaces.
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Spalling of brick in an 18th century chimney. The lower section is older than the upper.
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Although there are design modifications to reduce the risks, infiltrating runoff may freeze below the pavement, causing frost heave. Another issue is spalling damage. Spalling damage exclusively occurs on porous concrete pavement from salt application during the winter season. Thus porous paving is suggested for warmer climates.
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Mechanical spalling occurs at high stress contact points, for example, in a ball bearing. Spalling occurs in preference to brinelling where the maximal shear stress occurs not at the surface, but just below, shearing the spall off. One of the simplest forms of mechanical spalling is plate impact, in which two waves of compression are reflected on the free-surfaces of the plates and then interact to generate a region of high tensile stress inside one of the plates. Spalling can also occur as an effect of cavitation, where fluids are subjected to localized low pressures that cause vapor bubbles to form, typically in pumps, water turbines, vessel propellers, and even piping under some conditions.
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There are two drivers for spalling of concrete: thermal strain caused by rapid heating and internal pressures due to the removal of water. Being able to predict the outcome of different heating rates on thermal stresses and internal pressure during water removal is particularly important to industry and other concrete structures. Explosive spalling events of refractory concrete can result in serious problems. If an explosive spalling occurs, projectiles of reasonable mass (1–10 kg) can be thrust violently over many metres, which will have safety implications and render the refractory structure unfit for service.
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Spalling and spallation both describe the process of surface failure in which spall is shed. The terms spall, spalling, and spallation have been adopted by particle physicists; in neutron scattering instruments, neutrons are generated by bombarding a uranium target with a stream of atoms. The neutrons that are ejected from the target are known as spall.
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The two commonest effects are efflorescence and spalling. Salts that expand on crystallization in capillary gaps can cause surface spalling. For example, various magnesium and calcium salts in sea water expand considerably on drying by taking on water of crystallization. However, even sodium chloride, which does not include water of crystallization, can exert considerable expansive forces as its crystals grow.
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This service ended in September 1986 when the integrity of the Pencoyd Viaduct was questioned. The massive span was shedding pieces of concrete due to spalling. Further investigation by Urban Engineers determined that the bridge was safe and only needed surface work to end the spalling. In 1999, construction finished on a project to stabilize and refurbish the bridge, but train service did not resume as expected.
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Concrete wall cracking as steel reinforcing corrodes and swells. Rust has a lower density than metal, so it expands as it forms, cracking the decorative cladding off the wall as well as damaging the structural concrete. The breakage of material from a surface is called spalling. Detailed view of spalling probably caused by a too thin layer of concrete between the steel and the surface, accompanied by corrosion from external exposure.
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If the condensation rate of vapor is much faster than the escaping speed of vapor out of concrete due to sufficiently high heating rate or adequately dense pore structure, a large pore pressure can cause spalling. At the same time, thermal expansion on the surface will generate a perpendicular compressive stress opposing the tensile stress within the concrete. Spalling occurs when the compressive stress exceeds the tensile stress.
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The facade is mostly unchanged from the building's completion, although some spalling in the facade was patched with cast stone, and some design elements were removed or simplified.
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The mine's warhead is a shaped charge, optimized to produce maximum spalling behind armour — it can blast a 45-millimeter-diameter hole through a 100-millimeter-thick armour plate.
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Structures built of concrete and reinforced with metal rebar are also subject to damage by oxide jacking. Expansion of corroded rebar causes spalling of the concrete. Structures exposed to a marine environment, or where salt is used for de-icing purposes, are especially susceptible to this type of damage. Research in the 1960s showed that 22% of concrete bridge decks in Pennsylvania showed signs of spalling due to oxide jacking within four years of construction.
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There is some corrosion-related spalling to the reinforced concrete roof. ;Newcastle Reservoir No. 2 The reservoir stands in good condition, although the curtain wall addressing Tyrell Street and Brown Street exhibits some minor cracking along the upper edge, while some brickwork requires repointing. Some of the precast concrete plinth elements have been re-rendered. The steel reinforcement of the precast concrete cornice is corroded in some areas, giving rise to spalling.
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The cave has an unblackened roof, which may be due to rapid spalling of the roofs or updrafting winds acting as a vent and carrying smoke out of the cave.
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Micro pitting is a fatigue failure of the surface of a material commonly seen in rolling bearings and gears. It is also known as grey staining, micro spalling or frosting.
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There is considerable spalling of exterior concrete surfaces. The mine storehouse area is well preserved and restored, with several interpretive plaques describing the mine and net defense systems in Narragansett Bay.
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Unloading is the release of pressure due to the removal of an overburden. When the pressure is reduced rapidly, the rapid expansion of the rock causes high surface stress and spalling.
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Siliceous limestones can be very prone to the Alkali Silica Reaction (ASR) and their use as aggregate is often the cause of premature concrete degradation and problems in civil engineering (concrete spalling, bridges failure, ...).
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This increased elasticity greatly reduced the incidence of spalling and cracking under incoming fire, a valuable quality during long engagements. Ballistic testing shows that KCA and Krupp armour were roughly equal in other respects.
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The very small indentations can quickly lead to improper operation, such as chattering or excess vibration, which in turn can accelerate other forms of wear, such as spalling and ultimately, failure of the bearing.
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Granite dome exfoliation Exfoliation (or onion skin weathering) is the gradual removing of spall due to the cyclic increase and decrease in the temperature of the surface layers of the rock. Rocks do not conduct heat well, so when they are exposed to extreme heat, the outermost layer becomes much hotter than the rock underneath causing differential thermal expansion. This differential expansion causes sub-surface shear stress, in turn causing spalling. Extreme temperature change, such as forest fires, can also cause spalling of rock.
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The concrete bunkers have been subject to graffiti and fire but remain in good condition. There is some evidence of concrete cancer to the buildings in the form of exposed reinforcing where minor concrete spalling has occurred.
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Ten years later, after weather-related expansion and contraction of the bridge, and the shedding of pieces of concrete due to spalling, SEPTA closed the bridge on October 25, 1986, truncating service at Cynwyd and suspended service to three of the line's six stations (Ivy Ridge, Manayunk, and Walnut Hill). Between 1996 and 1999, the bridge was stabilized and refurbished. The effort determined that the internal steel reinforcement was not compromised, as SEPTA had feared. Further investigation by Urban Engineers determined that the bridge was safe and only needed surface work to stop the spalling.
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According to Freeman Dyson in the 1960s they would have had to actually perform a test with a real nuclear explosive to determine this; with modern simulation technology this could be determined fairly accurately without such empirical investigation. Another potential problem with the pusher plate is that of spalling—shards of metal—potentially flying off the top of the plate. The shockwave from the impacting plasma on the bottom of the plate passes through the plate and reaches the top surface. At that point spalling may occur damaging the pusher plate.
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The engine house and its associated boiler house were built near the foot of the hill and connected to the chimney stack by a long stone flue. With surrounding steep cliffs limiting the space for ore dressing, "spalling braces" (platforms attached to the shaft) were fitted to house spalling (breaking the ore into chunks for sorting) operations. In 1869 St Just Consolidated Mines abandoned the Cape Cornwall Mine, although it continued to operate independently until 1875. In 1879 the mine was once more reopened, this time under the ownership of St Just United.
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Such harm is usually irreversible. Freeze-thaw Spalling results when water freezes in the surface pores. The general term is Frost weathering. The water expands on freezing, causing the stone to spall, crumble, or even to crack through.
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It was designated a city landmark on December 28, 1981, because of its unique engineering style. An expansion joint suffered cracking and spalling during the 2001 Nisqually earthquake. The bridge has been retrofitted to make it more earthquake-resistant.
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Brass vehicle components at the tanker melted, indicating that temperatures were over , but no examples of melted copper (melting point ) were identified during the clean-up operations, indicating that maximum temperature range remained between those two points. The tiles and grout on the walls of the tunnel were damaged and spalled by intense heat all the way to the entrance portal, . Over the first east of the fire site, there was spalling of the concrete false ceiling and of the concrete walls behind the tiles. Spalling stopped at the steel reinforcement bars, approximately below the concrete surface.
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Salt spalling is a specific type of weathering which occurs in porous building materials, such as brick, natural stone, tiles and concrete. Dissolved salt is carried through the material in water and crystallizes inside the material near the surface as the water evaporates. As the salt crystals expand this builds up shear stresses which break away spall from the surface. Some engineers believe that porous building materials can be protected against salt spalling by treatment with penetrating sealants which are hydrophobic (water repellent) and will penetrate deeply enough to keep water with dissolved salts well away from the surface.
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Minor cracks on walls and beams at some floors are found on the building. Spalling of concrete is also observed on ceilings of some floors. Regular maintenance and monitoring is required to keep the structural slabs, beams and columns in good condition.
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The mine was actually a short prospecting tunnel that had been abandoned because no ore was found there. The mine opening was high and wide. At the entrance, there were cedar floor planks and squeeze caps logs in place to prevent spalling.
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Anti-spalling devices (spall liners), made of materials such as Kevlar, are commonly fitted to the interior surface of modern armoured vehicles to minimise spalling effects. Another reason for the declining use of HESH rounds is the preference of most armies for smoothbore cannons. Rifling decreases the penetrating power of HEAT warheads because the centrifugal force of the spinning projectile tends to disperse the shaped charge jet, but this same effect can assist a HESH shell by increasing the surface area of contact. The British Army has persisted with a rifled cannon on their Challenger 1 and Challenger 2 battle tanks partly to preserve the general purpose capability of HESH ammunition.
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Desquamation of dunite boulder Spalling is a common mechanism of rock weathering, and occurs at the surface of a rock when there are large shear stresses under the surface. This form of mechanical weathering can be caused by freezing and thawing, unloading, thermal expansion and contraction, or salt deposition.
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The original sandstone masonry blocks are in excellent condition with no significant signs of weathering or spalling. Likewise the condition of the mortar is also very good with only minor leakage emanating in various locations. The integrity of the dam is high; it retains water and is safe.
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The Abrams may also be fitted with explosive reactive armor over the track skirts if needed (such as the Tank Urban Survival Kit) and slat armor over the rear of the tank and rear fuel cells to protect against ATGMs. Protection against spalling is provided by a kevlar liner.
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In this application, a mud slab also prevents the plastic bar chairs from sinking into soft topsoil which can cause spalling due to incomplete coverage of the steel. Sometimes a mud slab may be a substitute for coarse aggregate. Mud slabs typically have a moderately rough surface, finished with a float.
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Enamel can be lost by abrasion or spalling, and is lost before dentine or bone are destroyed by the fossilisation process. In such a case, the 'skeleton' of the teeth would consist of the dentine, with a hollow pulp cavity. The organic part of dentine, conversely, is destroyed by alkalis.
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A large door exists to load the body container. Temperature in the primary chamber is typically between . Higher temperatures speed cremation but consume more energy, generate more nitric oxide, and accelerate spalling of the furnace's refractory lining. The secondary chamber may be at the rear or above the primary chamber.
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Spalling of an aluminium plate AMAP-L (liner) is the spall liner of AMAP. AMAP-L can be attached to soft-skinned or armoured vehicles. The spall cone which is normally 87° can be reduced to only 17°.AMAP-L brochure Over 30,000 vehicles have been fitted with spall lining systems of IBD.
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After building of a new refractory-lined industrial furnace or equipment, or refractory maintenance or relining of existing equipment, a necessary step is the start-up of the operation, which usually involves heating-up the unit in a controllable way, in order to prevent spalling or shortening of the materials' predicted lifetime.
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Otherwise, concrete can be subject to significant spalling. Up to about 300 °C, the concrete undergoes normal thermal expansion. Above that temperature, shrinkage occurs due to water loss; however, the aggregate continues expanding, which causes internal stresses. Up to about 500 °C, the major structural changes are carbonatation and coarsening of pores.
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A structural health monitoring (SHM) system equipped with sensors that check wind load and earthquake load to the building in real time has been applied to Haeundae Doosan We’ve the Zenith. The structural design was carried out by U.S. Thornton Tomasetti, a firm that also designed Taipei 101—a high-rise building in Taiwan. The Haeundae Doosan We’ve the Zenith has a refuge area every three floors, which can be utilized as a resting area or a hanging garden under normal circumstances and is used as a refuge space in the event of emergency. To prevent spalling, which is the explosion that can occur when the concrete is exposed to high temperatures, the buildings were built with high strength concrete using a spalling failure prevention method.
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Hobbs 2011, pp. 175–76 Dent in the flight deck of Formidable The detonation of the bomb put a large dent in the flight deck, around by and deep, with a hole in the center and much spalling from the underside.H.M. Ships Damaged or Sunk by Enemy Action 1952, p. 54.Hobbs 2017, p.
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Today the sculpture is in poor condition. The concrete surface suffers from spalling, and large chunks have broken away from the base, exposing the corroding rebar. The acrylic glass has become cloudy. In an effort to rehabilitate the piece, in 2006 the municipal government asked Halifax artist Philip Doucette to cover Life with mosaic tiles.
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A set of Cornish stamps Before the advent of heavy machinery the raw ore was broken up using hammers wielded by hand, a process called "spalling". Before long, mechanical means were found to achieve this. For instance, stamp mills were used in Samarkand as early as 973. They were also in use in medieval Persia.
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Freeze–thaw weathering is caused by moisture freezing inside cracks in rock. Upon freezing its volume expands, causing large forces which cracks spall off the outer surface. As this cycle repeats the outer surface repeatedly undergoes spalling, resulting in weathering. Some stone and masonry surfaces used as building surfaces will absorb moisture at their surface.
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On porous construction materials it may present a cosmetic outer problem only (primary efflorescence causing staining), but can sometimes indicate internal structural weakness (migration/degradation of component materials). Efflorescence may clog the pores of porous materials, resulting in the destruction of those materials by internal water pressure, as seen in the spalling of brick.
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The pedestal shows signs of spalling at the base, partly caused by the monument having been painted, and the relief detail is weathered. Originally the monument was surrounded by a stone kerbing and six posts linked by rails, with marble chips inside the border. The memorial now stands borderless and within two metres of the more recently erected columbarium.
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Some of the rocks show signs of spalling prior to removal from the fields. The wall is composed of larger rocks on the outside with smaller rocks piled into the cavity and used to fill the gaps between the larger ones. This process has been repeated upwards in the layers. There is no mortar used in the construction.
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Generally retrogressive spalling manifests, often accompanied by piping / internal erosion. The use of appropriate filters is critical to managing these materials; a preferred filter might be a #4 sized clear gravel / coarse- grained sand as a commercial aggregate which is generally readily available. Some non- woven filter fabrics are also suitable. As with all filters, D15 and D50 compatibility criteria should be checked.
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Furthermore, plastic deformation alters the form and geometry of the part. This reduces the precision and accuracy of the machine. The combination of higher friction and degraded form often leads to a runaway situation that continually worsens until the component fails. To prevent destructive burnishing, sliding must be avoided, and in rolling situations, loads must be beneath the spalling threshold.
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Some spalling is evident up the shaft. A lightning conductor is located on the southern side of the shaft. The vent shaft is prominently located and the surrounding topography makes this shaft a landmark for a considerable distance from most vantage points. A lack of large scale and high density buildings contributes to its relatively open visual qualities within this urban environment.
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Great care and expert advice must be consulted, however, to ensure that any coating is compatible with the substrate in terms of breathability (ability to allow the release of vapors from inside while preventing water intrusion), or other serious problems can be created. Chimneys show spalling damage before other portions of buildings because they are more exposed to the elements.
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Water freezing in the wall is another cause of spalling. In restoration work of pre-20th century structures, there should be a high ratio of lime and aggregate to Portland. This reduces the compressive strength of the mortar but allows the wall system to function better. The lime mortar acts as a wick that helps to pull water from the brick.
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This can help to prevent the older brick from spalling. Even when the brick is a modern, harder element, repointing with a higher ratio lime mortar may help to reduce rising damp. It may not be advisable for all consumers to use a straight lime mortar. With no Portland in the mix, there is less control over the setting of the mortar.
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One of two partial collapses to the south of No.4 shaft. Withdrawal of its maintenance regime after closure prompted a considerable deterioration in the tunnel's condition. In 2013–2014, two partial collapses occurred to the south of its midpoint. A number of severe bulges have also been recorded, as well as deep, longitudinal spalling to the south of No.4 shaft.
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The mortar battery and the caponiers are mostly derelict and overgrown with extensive damage to the brickwork. The main west caponier has suffered years of neglect resulting in extensive damage to its outer brickwork. A serious fire in 1989 caused considerable spalling to the interior roof arches. The gun embrasures, loopholes and sally ports have been blocked up to prevent access by vandals.
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Salt carried by fog or mist reached the rebar, causing corrosion and concrete spalling. From 1982 to 1986, the original bridge deck, in 747 sections, was replaced with lighter, stronger orthotropic steel deck panels over 401 nights without closing the roadway completely to traffic. The project not only restored the bridge to prime condition but also reduced the deck weight by 12,300 tons (11,160 metric tons).
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Surface of a concrete pillar with crack pattern of alkali–silica reaction Alkali–aggregate reaction is a term mainly referring to a reaction which occurs over time in concrete between the highly alkaline cement paste and non- crystalline silicon dioxide, which is found in many common aggregates. This reaction can cause expansion of the altered aggregate, leading to spalling and loss of strength of the concrete.
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Although these properties are usually advantageous, excessive burnishing leads to sub-surface cracks which cause spalling, a phenomenon where the upper layer of a surface flakes off of the bulk material. Burnishing may also affect the performance of a machine. The plastic deformation associated with burnishing creates greater heat and friction than from rubbing alone. This reduces the efficiency of the machine and limits its speed.
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The Centre has been beset by structural issues since its opening in 1999. In 2006, pool manager Jason Konrads said that, "Our roof has been leaking ever since we opened in 1999". Problems have included leaking water features, stained ceilings, concrete spalling, failed glazing and degraded finishes. The Cathedral Square area above the Centre has also been subjected to graffiti and has largely been neglected.
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The resulting spall is dangerous to crew and equipment, and may result in a partial or complete disablement of a vehicle and/or its crew. Many AFVs are equipped with spall liners inside their armor for protection. A kinetic energy penetrator, if it can defeat the armor, generally causes spalling within the target as well, which helps to destroy or disable the vehicle and its crew.
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The requirements for slab stabilization are strength and the ability to flow into or expand to fill small voids. Colloidal mixing equipment is necessary to use the pozzolan- cement grouts. The contractor must place the grout using a positive- displacement injection pump or a non-pulsing progressive cavity pump. A drill is also necessary but it must produce a clean hole with no surface spalling or breakouts.
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Selected colours achievable through anodization of titanium. The absorption of hydrogen and the formation of titanium hydride are a source of damage to titanium and titanium alloys (Ti /Ti alloys). This hydrogen embrittlement process is of particular concern when titanium and alloys are used as structural materials, as in nuclear reactors. Hydrogen embrittlement manifests as a reduction in ductility and eventually spalling of titanium surfaces.
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The school district has operated an Environmental and Vocational Educational Center in the keepers dwelling. Maintenance and restoration of the structure is part of the curriculum. Beginning in 1978, recurrent summer work/study programs greatly restored the station, which was then opened as a school. In 2003, a grant was obtained to repair spalling of the exterior brick work on the fog signal building.
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Rocks unearthed during this process were placed on the sled. Big rocks which would not fit on the sled would be broken up with spalling hammers. These pieces would then be placed on corn bags, an Islander on each corner, which would then be carried to the sled. When full, the sleds were taken to the end of the paddock where they were unloaded.
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It is caused by the expansion of ice when water freezes, putting considerable stress on the walls of containment. This is actually a very common process in all humid, temperate areas where there is exposed rock, especially porous rocks like sandstone. Sand can often be found just under the faces of exposed sandstone where individual grains have been popped off, one by one. This process is often termed frost spalling.
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A re- examination of whether the features were footprints was conducted by Morse et al. 2010. A comparison with other markings thought to be footprints was undertaken, from various species of humans and in varying substrates and ages. This suggested that the marks were made by recent mining activity using picks. "The picks produce a spalling effect which removes material more widely around the point of impact," says Morse.
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Most rockets are made of metals that can have an environmental impact during their construction. In addition to the atmospheric effects there are effects on the near-Earth space environment. There is the possibility that orbit could become inaccessible for generations due to exponentially increasing space debris caused by spalling of satellites and vehicles (Kessler syndrome). Many launched vehicles today are therefore designed to be re-entered after use.
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Resilient materials will have better impact resistance. Different materials can behave in quite different ways in impact when compared with static loading conditions. Ductile materials like steel tend to become more brittle at high loading rates, and spalling may occur on the reverse side to the impact if penetration doesn't occur. The way in which the kinetic energy is distributed through the section is also important in determining its response.
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Luten delineated several options, and the city chose among them. The city awarded the contract to build the new bridge to the Illinois Bridge Company of Chicago, who had been the contractor for the city's previous Luten arch bridges. Work on the new bridge began in October of 1920, and was completed in the fall of 1921. By 2006, the bridge had deteriorated, with concrete spalling on the arches and sidewalks.
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In later years, the bridge proved inadequate to support heavy truck traffic on Route 82. A steel support system was added to the east end in 1986, but the bridge continued to suffer from spalling concrete on the piers. The bridge was added to the Historic American Engineering Record in 1988. A new bridge was constructed upstream to carry Route 82 so that the old bridge could be closed.
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The Leopard 2 utilizes a slanted first armour stage (disturber), a specially hardened second stage (disrupter) and a softer, high ductility third stage (absorber). The disturber is designed to either entirely deflect or manipulate the direction of incoming kinetic energy penetrators. If penetration does occur, the projectile is then shattered and fragmented when striking the disrupter. Assuming the first two stages work properly, the absorber stage captures spalling and fragments.
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Water vapor from the interior of the building, or from the underside of pavers can escape. This will reduce efflorescence, spalling and scaling that can occur from water being trapped inside the brick substrate and freezing during cold weather. Years ago, the water repellents trapped moisture in the masonry wall creating more problems than they solved. Condensation in areas that experienced the four seasons were much more problematic than their counterparts.
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Because of the technological trend to reduce alkali content from the majority of refractories, the amount of combined water present in the moment of heat-up was reduced in the last years. On the other hand, recent developments which led to increases in mechanical strength, thermal shock resistance, erosion resistance, etc., also led to a reduction in permeability. Such permeability reduction caused an increase in vapor entrapment, which can lead to explosive spalling.
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The iron-and-wood armor of Iron-built ships used wood as part of their protection scheme. HMS Warrior was protected by 4.5 in (114 mm) of wrought iron backed by 15 in (381 mm) of teak, the strongest shipbuilding wood. The wood played two roles, preventing spalling and also preventing the shock of a hit damaging the structure of the ship. Later, wood and iron were combined in 'sandwich' armor, for instance in .
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Upon contact, 760 grams of explosives contained within it were detonated and produced a blast effect. This enabled about 20-25 mm of armour to be penetrated and caused secondary damage, such as spalling, on contact with thicker armour. This made the grenade very effective against earlier German tanks, but ineffective against later models, such as the Panzer IV and the Panzer V, leading to the RPG-43 replacing it in 1943.
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Firesetting is the process of exposing a rock face to high temperatures to induce cracking, spalling, and an overall increase to the brittleness of the rock in order to make it more susceptible to mining processes.Timberlake S., 2007. The Use of Experimental Archaeology/Archaeometallurgy for the Understanding and Reconstruction of Early Bronze Age Mining and Smelting Technologies. In S. L. Niece et al. (ed.) Metals and Mines: Studies in Archaeometallurgy 27-36.
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These neodymium magnets corroded severely after five months of weather exposure. Sintered Nd2Fe14B tends to be vulnerable to corrosion, especially along grain boundaries of a sintered magnet. This type of corrosion can cause serious deterioration, including crumbling of a magnet into a powder of small magnetic particles, or spalling of a surface layer. This vulnerability is addressed in many commercial products by adding a protective coating to prevent exposure to the atmosphere.
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The large stones would either be drilled and blasted > with dynamite to a convenient handling size, or snigged by horse team to the > boundary line. Local tradition also records that: > Wooden sleds, pulled by draught horses, followed around the paddocks as the > land was being cleared. Rocks unearthed during this process were placed on > the sled. Big rocks which would not fit on the sled would be broken up with > spalling hammers.
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The supercavitating propeller operates submerged with the entire diameter of the blade below the water line. Its blades are wedge-shaped to force cavitation at the leading edge and to avoid water skin friction along the whole forward face. As the cavity collapses well behind the blade, the supercavitating propeller avoids the spalling damage due to cavitation that is a problem with conventional propellers. An alternative to the supercavitating propeller is the surface piercing, or ventilated propeller.
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One benefit of such reactors is the relatively short half-lives of their waste products. For proton accelerators, the high-energy proton beam impacts a molten lead target inside the core, chipping or "spalling" neutrons from the lead nuclei. These spallation neutrons convert fertile thorium to protactinium-233 and after 27 days into fissile uranium-233 and drive the fission reaction in the uranium. Thorium reactors can generate power from the plutonium residue left by uranium reactors.
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When a unit has lost all available manpower, it will show up on the map as a dead soldier icon. Armour penetration in Combat Mission is given realistic treatment. Partial penetrations, spalling, and non-fatal penetrating hits are all modelled in the game, with realistic ballistic stats for both armour and armour-piercing weapons. Catastrophic damage to vehicles is modelled, with real life tank models prone to fires being equally prone to "brewing up" in the game.
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The major disadvantage of RC is that its steel reinforcement is prone to corrosion. Concrete is highly alkaline and forms a passive layer on steel, protecting it against corrosion. Substances penetrating the concrete from outside (carbonisation) lowers the alkalinity over time (depassivation), making the steel reinforcement lose its protection thus resulting in corrosion. This leads to spalling of the concrete, reducing the permanency of the structure as a whole and leading to structural failure in extreme cases.
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The design is used in military applications, high-performance racing boats, and model racing boats. It operates fully submerged with wedge-shaped blades to force cavitation on the entire forward face, starting at the leading edge. Since the cavity collapses well behind the blade, the supercavitating propeller avoids spalling damage caused by cavitation, which is a problem with conventional propellers. Supercavitating ammunition is used with German (Heckler & Koch P11) and Russian underwater firearms, and other similar weapons.
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However, other materials have proven to be effective, even lowering winter maintenance costs by preserving salt in the pavement itself. This also reduces the amount of storm water runoff that is contaminated with salt chlorides. Porous pavement designed to reduce frost heave and spalling damage has been used successfully in Norway. Furthermore, experience suggests that preventive measures with rapid drainage below porous surfaces be taken in order to increase the rate of snow melt above ground.
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Side of bridge The King Road–Whitefish River Bridge is a girder bridge built on two skewed through girders, supported by concrete abutments and a center pier. The deck is a concrete slab, with the girders rising above to form the guardrails on either side. A bronze plate designating the bridge as a "Trunk Line Bridge" is mounted on the girders’ inside walls. The structure is fundamentally unaltered, but has undergone a considerable amount of concrete spalling and chipping.
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This is mainly due to its ability to absorb impacts, making this an ideal material for RC aircraft for beginners and amateurs. Polypropylene is used in the manufacture of loudspeaker drive units. Its use was pioneered by engineers at the BBC and the patent rights subsequently purchased by Mission Electronics for use in their Mission Freedom Loudspeaker and Mission 737 Renaissance loudspeaker. Polypropylene fibres are used as a concrete additive to increase strength and reduce cracking and spalling.
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A fire in one part of the collision can quickly spread via spilled gasoline and cover the entire crash area. Multiple-vehicle collisions can also overwhelm local firefighting, ambulance, and police services making speedy rescues more difficult. If the collision takes place in a remote area, getting medical help to the scene can be a daunting task. The destruction and intense heat of fires can also damage roadways, particularly by melting and burning the asphalt or spalling concrete surfaces.
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Two sites, 62.46 and 62.47, include representations of small European sailing ships. Dr. Mark Hedden, an archaeologist specialized in Maine's rock art, believes them to be consistent with small ships used by Plymouth Colony traders who are known to have paid visits to Machias Bay in the early 1630s. They are located on rock ledges in the bay, and only 62.46 is complete; the panel at 62.47 has suffered spalling, and all of its figures are fragmentary.
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Spalling at elevated temperature is pronounced, driven by vapor pressure and thermal stresses. When the concrete surface is subjected to a sufficiently high temperature, the water close to the surface starts to move out from the concrete into atmosphere. However, with a high temperature gradient between the surface and the interior, vapor can also inwards where it may condense with lower temperatures. A water- saturated interior resists the further movement of vapor into the mass of the concrete.
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Spalling Examining the structure before working will also help establish the strength and permeability of the original mortar in order to match the new. It helps to establish what the original components of the old mortar are in order to find the best match. It is essential that the mortar used for repointing have similar performance characteristics to the original mortar used in a building. Such performance characteristics include permeability, compressive strength, and coefficient of thermal expansion.
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Formstone prevents the historic brick from breathing and the accumulation of moisture causes cracks to form.“Baltimore City Historic Preservation Design Guidelines,” Baltimore City Department of Planning, Commission for Historical and Architectural Preservation, adopted December 8, 2015. This moisture combined with the freeze-thaw cycle can damage the Formstone material and, if left uncorrected, can lead to further deterioration and penetration of moisture into the underlying brick. This can lead to spalling, efflorescence, and loosened mortar joints on the brick façade.
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Scabbing, also known as spalling, is the violent separation of a mass of material from the opposite face of a plate or slab subjected to an impact or impulsive loading, without necessarily requiring that the barrier itself be penetrated. While soil is a less dense material, it also does not transmit shock waves as well as concrete. So while a penetrator may actually travel further through soil, its effect may be lessened due to its inability to transmit shock to the target.
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Usually, the load-bearing walls are supported on a continuous strip foundation while a column rests on brick footings, which were in turn supported on bakau (mangrove) timber piles. Lime mortar is usually used in the construction of the brickwork in early buildings and due to the damp evaporation ability, which slows down the proliferation of the spalling of surface finishes, such as plaster and paintwork, caused by accumulated damp inside the structural element as compared to cement mortar used in later construction.
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The original bridge used a concrete deck. Salt carried by fog or mist reached the rebar, causing corrosion and concrete spalling. From 1982 to 1986, the original bridge deck, in 747 sections, was systematically replaced with a 40% lighter, and stronger, steel orthotropic deck panels, over 401 nights without closing the roadway completely to traffic. The roadway was also widened by two feet, resulting in outside curb lane width of 11 feet, instead of 10 feet for the inside lanes.
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It has been common since the widespread availability of Portland cement to see London stock brickwork repointed using much stronger cement mortar. As repointing consists of replacing the outer 20–40mm of mortar, the effect of this is to make the outer 20–40mm of the brickwork harder and stronger than the interior of the wall. This can lead to spalling of the brick surface, and can also encourage the bulging associated with snapped headers.Bidwell, T. G., "The Conservation of Brick Buildings".
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However, the high silhouette and low, hull-mounted 75 mm were tactical drawbacks since they prevented fighting from a hull-down firing position. In addition, the use of riveted hull superstructure armor on the early versions led to spalling, where the impact of enemy shells caused the rivets to break off and become projectiles inside the tank. Later models were built with all-welded armor to eliminate this problem. These lessons had already been applied to the design and production of the M4.
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Rock bursts result from brittle fracturing of rock, causing it to collapse rapidly with violent spalling of rock that is approximately 100 to 200 tonnes, or more. This release of energy reduces the potential energy of the rock around the excavation. Another explanation is that the changes brought about by the mine's redistribution of stress trigger latent seismic events, deriving from the strain energy produced by its geological aspects. The likelihood of rock bursts occurring increases as the depth of the mine increases.
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In the late 1920s another addition was planned under the direction of Louis A. Simon, Superintendent of the Architectural Section of the Treasury Department. The design was intended to duplicate the earlier facades, but an unforeseen problem arose. During construction of the building's final addition, extensive cracking and spalling were discovered in the soft Kyune sandstone that faced the 1905 and 1912 sections. As a consequence, the addition was constructed entirely in granite and nearly all the existing facades were refaced to match.
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Too much concrete cover can cause bigger crack widths which also compromises the local guard. As rust takes up greater volume than the steel from which it was formed, it causes severe internal pressure on the surrounding concrete, leading to cracking, spalling, and, ultimately, structural failure. This phenomenon is known as oxide jacking. This is a particular problem where the concrete is exposed to salt water, as in bridges where salt is applied to roadways in winter, or in marine applications.
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The project involved cutting out loose concrete where spalling was evident, cleaning, treating the steel reinforcement and repairing the concrete. All loose paint and moss was removed, anti-mould solution was applied, a sealer coat was added as well as a coat of bitumen and woven fibreglass cloth was used to cover all the cracks and repairs. Finally two more coats of bitumen, two colour coats and two coats of clear plastic were applied. The new colour chosen was beige.
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In addition, such zirconates may have a high concentration of oxygen ion vacancies, which may facilitate oxygen transport and exacerbate the formation of the TGO. With a large enough TGO, spalling of the coating may occur, which is a catastrophic mode of failure for TBCs. The use of such coatings would require addition coatings that are more oxidation resistant, such as alumina or mullite. The bond-coat is an oxidation-resistant metallic layer which is deposited directly on top of the metal substrate.
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Three meals were supplied daily, as specified by Government regulations. While some of the properties had been cleared initially by the selectors, the role of the Islanders was to clear the remaining virgin scrub: felling, burning and clearing the large volcanic stones, which were collected and sometimes drilled and blasted. Rocks unearthed during this process were placed on wooden sleds, pulled by draught horses. Big rocks which would not fit on the sled would be broken up with spalling hammers.
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The mortar must have greater vapor permeability and softer compressive strength than the original mortar. The mortar should also not be stronger (in compressive strength) than the masonry units because it will not have give. Rather than the mortar relieving the stress, the masonry units will, which will cause further damage to the masonry unit, such as cracking or spalling. This is when the face or outer section of a masonry unit breaks away from the rest of the unit.
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Exfoliating slabs of granite, on Half Dome in Yosemite National Park, USA Exfoliating granite is a granite undergoing exfoliation, or onion skin weathering (desquamation). The external delaminated layers of granite are gradually produced by the cyclic variations of temperature at the surface of the rock in a process also called spalling. Frost and ice expansion in the joints during the winter accelerate the alteration process while the most unstable loosen external layers are removed by gravity assisted by runoff water.
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Although the hull could deflect heavy machine gun fire of up to 12.7mm AP, it was easily penetrated by rocket propelled grenades, which could destroy the vehicle if the spalling contacted the caseless main gun rounds. Like the M113 armored personnel carrier, it was also vulnerable to mines. Swimming capability was provided by a flotation screen, similar to that used by the World War II, amphibious DD Tanks. The front armor was overlain by a wooden "surfboard", actually three folded layers, hinged together.
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This hygroscopic gel swells and increases in volume when absorbing water: it exerts an expansive pressure inside the siliceous aggregate, causing spalling and loss of strength of the concrete, finally leading to its failure. ASR can lead to serious cracking in concrete, resulting in critical structural problems that can even force the demolition of a particular structure. The expansion of concrete through reaction between cement and aggregates was first studied by Thomas E. Stanton in California during the 1930s with his founding publication in 1940.
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Works to the Rose Bay Promenade since completion were generally limited to maintenance and repairs until 2007, when a major upgrade occurred. An engineering study in 2003 into the condition of the concrete seawall, balustrade, stairs and light standards found evidence of cracking and salt attack in the seawall and varying degrees of spalling and corrosion in the other elements. The study proposed various remedial measures. The major restoration and upgrade works carried out in 2007 included repairs to the balustrade, light standards and stairs.
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Very bad flat spot A flat spot, or wheel flat, also called spalling or shelling, is a fault in railroad wheel shape. A flat spot occurs when a rail vehicle's wheelset is dragged along the rail after the wheel/axle has stopped rotating. Flat spots are usually caused by use of the emergency brake, or slip and slide conditions that causes wheels to lock up while the train is still moving. Flat spots are more common in the autumn and winter when the rails are slippery.
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Hydronic tubes that are cast into concrete slabs will create an uneven heating pattern in the concrete thus causing uneven stresses to occur within the concrete slab. The use of high temperature fluid entering a very cold slab will create stress cracks and possible spalling of the concrete surface. Close tube spacing and a controlled slow increase in temperature will lessen the negative effects of a tube based system. Another method is to maintain a minimum slab temperature above freezing throughout the winter season.
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One rule of thumb is to consider all pink colored concrete as damaged that should be removed. Fire will expose the concrete to gases and liquids that can be harmful to the concrete, among other salts and acids that occur when gases produced by a fire come into contact with water. If concrete is exposed to very high temperatures very rapidly, explosive spalling of the concrete can result. In a very hot, very quick fire the water inside the concrete will boil before it evaporates.
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Common fireproofing methods for structural steel include intumescent, endothermic, and plaster coatings as well as drywall, calcium silicate cladding, and mineral wool insulating blankets.Best Practice Guidelines for Structural Fire Resistance Design of Concrete and Steel Buildings, NIST Technical Note 1681, L. T. Phan, J. L. Gross, and T. P. McAllister, 2010. (View report) Concrete building structures often meet code required fire-resistance ratings, as the concrete thickness over the steel rebar provides sufficient fire resistance. However, concrete can be subject to spalling, particularly if it has an elevated moisture content.
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The Home Improvement Programme (HIP) is a programme announced by HDB, during the National Day Rally in August 2007 that replaced the Main Upgrading Programme (MUP). The HIP offers lessees a choice on the works they want to be included in the upgrading of their flats. It also helps lessees deal with common maintenance problems in ageing flats, such as spalling concrete and ceiling leaks, in a systematic and comprehensive manner. Flats are eligible for HIP twice, one at 30 years old and one at 60-70 years old.
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1264 Instead of rounded forms, the turrets of tanks using Chobham armour typically have a slab-sided appearance. The backing plate reflects the impact energy back to the ceramic tile in a wider cone. This dissipates the energy, limiting the cracking of the ceramic, but also means a more extended area is damaged. Spalling caused by the reflected energy can be partially prevented by a malleable thin graphite layer on the face of the ceramic absorbing the energy without making it strongly rebound again as a metal face plate would.
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Example of the spalling damage caused by High-explosive squash head. High- explosive squash head (HESH) is a type of explosive ammunition that is somewhat effective against tank armor and is also useful against buildings, fortifications and infantry. It was fielded chiefly by the British Army as the main explosive round of its main battle tanks during the Cold War. It was also used by other military forces, particularly those that acquired the early post-World War II British 105 mm Royal Ordnance L7A1, including Germany, India, Israel and Sweden.
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For purposes of fireproofing, an adequate thickness of cement concrete cover or protective cladding is necessary. The addition of 1 kg/m3 of polypropylene fibers to concrete has been shown to reduce spalling during a simulated fire. (The improvement is thought to be due to the formation of pathways out of the bulk of the concrete, allowing steam pressure to dissipate.) Another problem is the effectiveness of shear reinforcement. FRP rebar stirrups formed by bending before hardening generally perform relatively poorly in comparison to steel stirrups or to structures with straight fibres.
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The precast concrete double-wall panel has been in use in Europe for decades. The original double-wall design consisted of two wythes of reinforced concrete separated by an interior void, held together with embedded steel trusses. With recent concerns about energy use, it is recognized that using steel trusses creates a "thermal bridge" that degrades thermal performance. Also, since steel does not have the same thermal expansion coefficient as concrete, as the wall heats and cools any steel that is not embedded in the concrete can create thermal stresses that cause cracking and spalling.
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A direct hit usually destroyed or damaged the target's tracks and suspension, immobilizing it. While the low-velocity 152mm shell did not generally penetrate heavy armor, it frequently killed or severely wounded the crew through spalling (splintering) inside the hull as well as injuries caused by blast concussion. Surviving crew were often left with an immobilized vehicle which had to be hurriedly abandoned before being destroyed. For anti-tank operations following the July 1943 Battle of Kursk, armour-piercing ammunition was developed, with an eye towards giving the howitzer a more traditional anti-tank capability.
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Early European iron armour consisted of between four and five inches (roughly 10 to 13 cm) of wrought iron backed by between 18 and 36 inches (roughly one-half to one metre) of solid wood. After considerable testing, the committee found that wood prevented spalling, cushioned the shock of a hit from damaging the structure of the ship and distributed the force over a larger area, which prevented penetration. The drawback of using wood and iron was extreme weight. Experiments with reducing or eliminating wooden backing to save weight proved unsuccessful.
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Girls in their mid-teens cobbed the resulting chunks, separating the valuable ore from waste rock. Grown women would carry out the heavy manual labour of breaking rocks with hammers ('spalling'), of crushing sorted ore to small grains ready for smelting ('bucking') and of transporting ore between various pieces of apparatus. An experienced bal maiden working as a spaller would produce approximately one ton (2240 lb; 1016 kg) of broken ore per day, depending on the type of stone. In the tin mines, in which ore could be crushed far more finely than copper before smelting, cobbing and bucking did not take place.
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The program was delayed by about a month by late radiobarium shipments, as the test scheduled for 15 August was not conducted until mid- September. The first test with radiobarium was fired on 22 September. In late August and at the request of Rossi's group, the RaLa group was reformed under the leadership of Rossi, and Alvarez and his group took over the exploding bridgewire detonator research. At the suggestion of Robert Christy solid spheres instead of the originally intended hollow ones were chosen for the pit, in order to reduce the problems with jets and spalling.
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Elmet Towers in Swarcliffe, Leeds, showing the dereliction that led to its demolition Coleman's 1985 work argues that in trying to emulate Le Corbusier's ideas, the tower block planners only succeeded in encouraging social problems.Lund, B. (1996) Housing problems and housing policy, New York, Longman, p. 127. Although architects and local authorities intended the opposite, tower blocks quickly became, as Hanley sharply stated, 'slums in the sky'. Due to demanding deadlines, complicated construction practices were rushed and many tower blocks experienced structural decay as a result – roofs leaked, concrete suffered spalling, steel corroded, and damp penetrated the buildings.
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Lastly, in 1886, the six-rank Odell organ was purchased from Jardine and Son in New York for ($ in contemporary dollars) in 1886. There have been no significant changes to the church interior since then, other than the replacement of most of the other stained glass in the 1950s. The parish house was built at that time as well, and the brick on the church exterior painted over in white in the hope of preventing spalling. A half century later, in the early 2000s, the organ was restored and then designated a historic instrument by the Organ Historical Society.
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There is evidence of past patch repair work around numerous areas of the shaft and pedestal, and presently there is evidence of spalling and reinforcement corrosion on the southern wall of the pedestal particularly. The area surrounding the vent shaft is dominated by late 20th century flats and to the north is the Railway line across Railway Parade. The immediate ground surrounding the shaft is cleared which forms part of a small reserve at the corner of Wentworth Road and Railway Parade. A manhole is located some 15 metres to the east adjacent the footpath to Railway Parade.
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Lithic morphology in ash is generally controlled by the mechanical properties of the wall rock broken up by spalling or explosive expansion of gases in the magma as it reaches the surface. The morphology of ash particles from phreatomagmatic eruptions is controlled by stresses within the chilled magma which result in fragmentation of the glass to form small blocky or pyramidal glass ash particles. Vesicle shape and density play only a minor role in the determination of grain shape in phreatomagmatic eruptions. In this sort of eruption, the rising magma is quickly cooled on contact with ground or surface water.
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Cerium tarnishes in air, forming a spalling oxide layer like iron rust; a centimeter-sized sample of cerium metal corrodes completely in about a year. It burns readily at 150 °C to form the pale-yellow cerium(IV) oxide, also known as ceria: :Ce + O2 → CeO2 This may be reduced to cerium(III) oxide with hydrogen gas. Cerium metal is highly pyrophoric, meaning that when it is ground or scratched, the resulting shavings catch fire. This reactivity conforms to periodic trends, since cerium is one of the first and hence one of the largest (by atomic radius) lanthanides.
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In corrosion, spalling occurs when a substance (metal or concrete) sheds tiny particles of corrosion products as the corrosion reaction progresses. Although they are not soluble or permeable, these corrosion products do not adhere to the parent material's surface to form a barrier to further corrosion, as happens in passivation. Spallation happens as the result of a large volume change during the reaction. In the case of actinide metals (most notably the depleted uranium used in some types of ammunition), the material expands so strongly upon exposure to air that a fine layer of oxide is forcibly expelled from the surface.
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At the point where the compression and tension waves intersect, a high-stress zone is created in the metal, causing pieces of steel to be projected off the interior wall at high velocity. This fragmentation by blast wave is known as spalling, with the fragments themselves known as spall. The spall travels through the interior of the vehicle at high velocity, killing or injuring the crew, damaging equipment, and/or igniting ammunition and fuel. Unlike high-explosive anti-tank (HEAT) rounds, which are shaped charge ammunition, HESH shells are not specifically designed to perforate the armour of main battle tanks.
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Therefore, a straight lime mortar joint should be repointed in kind. Due to the popularity of Portland cement, this often is not the case. A wall system needs a balance between the mortar and brick that allows the mortar to be the weak part of the unit. When mortar is stronger than the brick, it prevents any natural movement in the wall and the faces of the brick will begin to deteriorate, a process known as spalling, the process by which the outer face of a brick degrades and can flake off or turn to powder.
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The two large windows at the Verney Road end of the church were dedicated as memorial windows to Mr and Mrs Taylor. In 1963 the original Trustee committee was replaced by the Property Board of Graceville Methodist Church who selected the restoration of the church and memorial hall as its jubilee project. The most important issues were the spalling of the concrete in the hall and church owing to the penetration of moisture which caused the steel reinforcing to rust, and damage and disfigurement caused by pigeon droppings. The restoration work was completed in 1965 by Building Plastics.
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Since opening, the McEwen Bridge has not been subjected to major rehabilitation or repair and is currently in an advanced state of disrepair. In 2010, the City of Vaughan initiated an environmental assessment study for the bridge's proposed rehabilitation. The bridge scored 45.1 on the Bridge Condition Index by the Ministry of Transportation of Ontario, which is considered poor condition. Its structural integrity has been compromised in many ways, including damage to the deck, bottom arch chord, vertical arch hangers, floor beams and guard rails, with large sections affected by spalling, all of which poses significant risk to users.
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Unweave the Weave, a project to eliminate weaving at the I-694 overlap, was completed in 2008. The 1965 bridge just north of downtown Saint Paul carrying a daily traffic volume of 148,000 vehicles over Cayuga Street and the BNSF Railway line was rated by MnDOT as meeting minimum tolerable limits in 2006. Its superstructure and substructure were described as poor with advanced section loss, deterioration, spalling, or scour. As the fourth busiest bridge in the state, it was scrutinized following the collapse of the I-35W Mississippi River Bridge in nearby Minneapolis on August 1, 2007.
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Multiple strikes (from hitting a bird flock) on twin-engine jet aircraft are very serious events because they can disable multiple aircraft systems, requiring emergency action to land the aircraft, as in the January 15, 2009 forced ditching of US Airways Flight 1549. Modern jet aircraft structures must be able to withstand one collision; the empennage (tail) must withstand one bird collision. Cockpit windows on jet aircraft must be able to withstand one bird collision without yielding or spalling. At first, bird strike testing by manufacturers involved firing a bird carcass from a gas cannon and sabot system into the tested unit.
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These original Horses of Saint Mark have been relocated indoors, and replaced by replicas. The cornice at the top of the Land Title Building was damaged by oxide jacking. Oxide jacking damage was discovered after a flood at the Farnsworth House. Oxide jacking has caused concrete spalling on walls of the Herbst Pavilion at Fort Mason Center in San Francisco In a 1987 article in New Scientist, Jack Harris reported that oxide jacking has caused significant damage to many historic structures in the United Kingdom, including St Paul's Cathedral, the British Museum and the Albert Memorial in London, Gloucester Cathedral, St. Margaret's Church in King's Lynn, Winchester Cathedral, and Blackburn Cathedral.
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Praseodymium metal tarnishes slowly in air, forming a spalling oxide layer like iron rust; a centimetre-sized sample of praseodymium metal corrodes completely in about a year. It burns readily at 150 °C to form praseodymium (III,IV) oxide, a nonstoichiometric compound approximating to Pr6O11: :12 Pr + 11 O2 → 2 Pr6O11 This may be reduced to praseodymium(III) oxide (Pr2O3) with hydrogen gas.Greenwood and Earnshaw, pp. 1238–9 Praseodymium(IV) oxide, PrO2, is the most oxidised product of the combustion of praseodymium and can be obtained by either reaction of praseodymium metal with pure oxygen at 400 °C and 282 bar or by disproportionation of Pr6O11 in boiling acetic acid.
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The frost-thaw cycle has caused some cracking and spalling of the concrete. In 1980, the building was listed in the National Register of Historic Places as "Great Blue Hill Weather Observatory", as part of a multiple property nomination by the Commonwealth of Massachusetts entitled "Prehistoric and Historic Resources of the Blue Hills and Neponset River Reservations and Selected Adjacent Lands". In 1981, the Metropolitan District Commission transferred responsibility for the observatory to the Blue Hill Weather Club, a local group of supporters, who plan to restore the observatory and establish a weather museum on the site. The observatory will be kept open to continue its record of continuous weather observations.
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Once repairs were made, a new contractor was hired to complete the bridge once the initial contractor (Stevin Construction) and the state agreed to terminate their contract in exchange for both sides dropping their lawsuits over the accident. The new contractor developed a method of heating the concrete to allow construction during the winter. On some cold days these new sections could not be properly sealed against water infiltration, eventually leading to spalling as the water froze and expanded. Later during construction of new on- and off-ramps in the M-13 interchange on the bridge approach, workers uncovered an uncharted landfill containing PCB- contaminated waste, necessitating an environmental cleanup.
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In the North African campaign, the M3 was generally appreciated for its mechanical reliability,initially there were problems with engine wear and suspension springs (Fletcher p 92) good armor and heavy firepower. In all three areas, it outclassed the available British tanks and was able to fight German tanks and towed anti-tank guns. The tall silhouette and low, hull-mounted 75 mm were severe tactical drawbacks, since they prevented the tank from fighting from hull-down firing positions. The use of riveted armor led to a problem called "spalling", whereby the impact of enemy shells would cause the rivets to break off and become projectiles inside the tank.
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While the Russians knocked out at least seven German Ferdinands in SU-152 ambushes at Kursk during one operation, German after-action engineers were able to repair, recrew and return nearly all to battle the next day. This has been attributed to the gun's reliance on blast rather than penetration, which killed the crew and destroyed the vehicle's interior via concussion and spalling without harming the ammunition supply or chassis. In response, Soviet doctrine was changed by ordering SU-152 crews to continue firing on incapacitated vehicles until the turret was knocked off.The Combat History of Schwere Panzer Abteilung 654, by Karlheinz Munch, pp.
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The Barwon Sewer Aqueduct has become an issue in terms of its condition and the cost of conservation, although it is still of relatively high integrity. The structure was repaired continuously from 1977-1980 using shotcrete to cover reinforcing exposed by spalling of the concrete through fumes and carbonation. The loss of cover to reinforcing appears to be limited for the most part to vertical and diagonal members of the trusses where the members are smaller in cross section. A report completed in 1995 for Barwon Water concluded that, due to its condition, there was no factor of safety and the structure could collapse at any time.
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Rock spalling (or thermal exfoliation) accelerates weathering of rock and potentially the release of some nutrients. Increase in the pH of the soil following a fire is commonly observed, most likely due to the formation of calcium carbonate, and the subsequent decomposition of this calcium carbonate to calcium oxide when temperatures get even higher. It could also be due to the increased cation content in the soil due to the ash, which temporarily increases soil pH. Microbial activity in the soil might also increase due to the heating of soil and increased nutrient content in the soil, though studies have also found complete loss of microbes on the top layer of soil after a fire.
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Small volumes of un-melted and relatively un-shocked material may be spalled at very high relative velocities from the surface of the target and from the rear of the impactor. Spalling provides a potential mechanism whereby material may be ejected into inter-planetary space largely undamaged, and whereby small volumes of the impactor may be preserved undamaged even in large impacts. Small volumes of high-speed material may also be generated early in the impact by jetting. This occurs when two surfaces converge rapidly and obliquely at a small angle, and high-temperature highly shocked material is expelled from the convergence zone with velocities that may be several times larger than the impact velocity.
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SHR listing # 00084 The Fishwick house was then rented by Nancy and Rawson Deans who later purchased the house in 1945 for 1,450 pounds. In 1976, Andrew and Susan Kirk, the present owners, purchased the Fishwick house for $98,000. During the 1970s and 1980s, a major works program was undertaken to restore the fabric of the property, including the rebuilding of the kitchen, replacement of the bituminous and pebble roof membrane, underpinning of the north-east corner, repair of concrete spalling to internal walls, and upgrading of water, gas, sewage, stormwater and electrical services. A further restoration program was completed in 1998 under the supervision of conservation architects, including restoration of interior finishes, interior conservation and repair work.
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Maentwrog, Plas Tan y Bwlch. Occasional Paper No. 1.Timberlake 2007 Typically firesetting experiments are conducted by setting a fire next to a predetermined rock face while taking measurements on the amount of and type of fuel used, temperatures of the fire and rock face, the amount of spalling before and after excavation, as well as the amount of time required for the different procedures.Crew 1990Lewis 1990Pickin and Timberlake 1988Timberlake 1990 This examination allows for several possible inferences to be made about the mining process including the total amount of fuel a mining site may have needed to complete and its effects on the surrounding environment as well as how mining labor could have been organized.
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The combination of these effects can lead to hearing loss, tinnitus, headache, vertigo (dizziness), and difficulty processing sound. In general, primary blast injuries are characterized by the absence of external injuries; thus internal injuries are frequently unrecognized and their severity underestimated. According to the latest experimental results, the extent and types of primary blast-induced injuries depend not only on the peak of the overpressure, but also other parameters such as number of overpressure peaks, time-lag between overpressure peaks, characteristics of the shear fronts between overpressure peaks, frequency resonance, and electromagnetic pulse, among others. There is general agreement that spalling, implosion, inertia, and pressure differentials are the main mechanisms involved in the pathogenesis of primary blast injuries.
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The USMC's preferred technique to prevent this is a hard-throw, skip/bounce technique, where the grenade is thrown hard enough that it bounces or skips around, being hard to pick up and throw back – this is applicable when clearing a room, for instance. In other uses, such as to reach upper floors of a building, a grenade may be lobbed for greater distance or accuracy. Throwing a grenade upstairs is dangerous, due to the risk of it falling back down; it is much safer to throw a grenade downstairs, so it is safer to capture a building from the top, rather than the bottom. Grenades generally explode near the floor, causing spalling downwards towards lower floors.
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Portions of the armour plating on earlier models of the T-26 used riveted construction and were very vulnerable to both types of attacks. The use of riveted armour on some older T-26 models led to "spalling", when the impact of enemy shells, even if they failed to disable the tank or kill the crew on their own, caused the rivets to break off and become projectiles inside the tank.Baryatinskiy (2006, in Russian), pp. 84–85 On the eve of World War II, T-26s served mainly in separate light tank brigades (each brigade had 256–267 T-26s) and in separate tank battalions of the rifle divisions (one company of T-26s consisted of 10–15 tanks).
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The introduction of wire mesh has the potential to hasten deterioration of both the masonry and the stucco finish as the slightest amount of moisture will lead to rust developing on the wire mesh, which expands as it rusts. This may lead to the spalling of not only the new stucco, but also of the masonry itself. > After thoroughly dampening the masonry or wood lath, the first, scratch coat > should be applied to the masonry substrate, or wood or metal lath, in a > thickness that corresponds to the original if extant, or generally about ″ > to ″. The scratch coat should be scratched or crosshatched with a comb to > provide a key to hold the second coat.
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It was notable from all other Lycoming models by incorporating hydraulic lifters that were barrel shaped instead of mushroom type, in an attempt to make the lifters possible to be serviced without having to disassemble the entire engine case, but the higher load on the cam lobes resulted in severe spalling. Multiple service bulletins and airworthiness directives have been issued regarding this specific model, and multiple modifications exist to attempt to mitigate its design defects.Lycoming Service Bulletins #424 (new lifter modification), #446C, #435C, #1406B ("T" case modification), Ney Nozzles modification ;O-320-H2BD : at 2700 rpm, Minimum fuel grade 100LL avgas, compression ratio 9.00:1. Same as the H2AD but with a D4RN-2200 retard breaker dual magneto.
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The Fire Island Inlet Bridge, an integral part of the Robert Moses Causeway, is a two-lane, steel tied arch span with a concrete deck that carries the parkway over Fire Island Inlet. Construction of the Fire Island Bridge was completed in 1964 and although a relatively young structure, (less than 50 years old), its concrete deck has suffered from severe chloride ingress resulting in cracks, spalling, and the formation of potholes. The Fire Island Inlet span of the Robert Moses Causeway connects to Robert Moses State Park on the western tip of Fire Island. The Fire Island Inlet Bridge is located south of the State Boat Channel Bridge, a long bascule bridge modeled after Brooklyn's Mill Basin Drawbridge.
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Example of flat piece of concrete having dislodged with corroded rebar underneath, Welland River bridge across Queen Elizabeth Way in Niagara Falls, Ontario. The expansion of the corrosion products (iron oxides) of carbon steel reinforcement structures may induce mechanical stress that can cause the formation of cracks and disrupt the concrete structure. If rebars have been improperly installed or have inadequate concrete cover at surfaces exposed to the elements, oxide jacking and spalling can occur during the structure's lifetime: flat fragments of concrete are detached from the concrete mass as a result of the rebar's corrosion. Corrosion and its prevention is of considerable importance in the design and construction of steel reinforced concrete structures.
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When the reactor went critical on May 9, 1944 with , the accuracy of Christy's figures raised the laboratory's confidence in T Division's calculations. The discovery by Emilio Segrè's group in April and May 1944 of high levels of plutonium-240 in reactor-produced plutonium meant that an implosion-type nuclear weapon was required, but studies indicated that this would be extremely difficult to achieve. By August 1944, the calculations had been made of how an ideal spherical implosion would work; the problem was how to make it work in the real world where jets and spalling were a problem. Christy worked in Rudolf Peierls's T-1 Group, which studied the theory of implosion.
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The most significant damage outside the Coalinga area was at Avenal, southeast of the epicenter. A disaster assessment by the American Red Cross listed the following statistics on damage in the area: almost destroyed – 309 single-family houses and 33 apartment buildings; major damage – 558 single- family houses, 94 mobile homes, and 39 apartment buildings; and minor damage – 811 single-family houses, 22 mobile homes, and 70 apartment buildings. Most public buildings, including the City Hall, hospital, schools, fire house, post office, and police station, sustained only minor damage. Six bridges of 60 in the area sustained measurable structural damage, which consisted of hairline cracks and spalling at the top of the support columns, fracturing and displacement of wing walls and parapets, and settlement of fill.
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On January 30, 2016, a chunk of concrete the size of an automobile tire fell from the tunnel wall into the slow lane of eastbound traffic on the lower deck of the Yerba Buena Tunnel, causing a minor accident. The concrete fell from where the upper deck is connected to the tunnel wall. Based on an examination of photographs, a professor from Georgia Tech postulated that water infiltration into the concrete wall had caused the reinforcing steel to corrode and expand, forcing a chunk of the tunnel wall out. A subsequent California Department of Transportation (Caltrans) investigation identified 12 spots on both sides of the tunnel wall in the lower deck space showed signs of corrosion-induced damage, but no immediate risk of further spalling.
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The life of a rolling bearing is expressed as the number of revolutions or the number of operating hours at a given speed that the bearing is capable of enduring before the first sign of metal fatigue (also known as spalling) occurs on the raceway of the inner or outer ring, or on a rolling element. Calculating the endurance life of bearings is possible with the help of so-called life models. More specifically, life models are used to determine the bearing size – since this must be sufficient to ensure that the bearing is strong enough to deliver the required life under certain defined operating conditions. Under controlled laboratory conditions, however, seemingly identical bearings operating under identical conditions can have different individual endurance lives.
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In 1851, Imperial Commissioner Sengge Rinchen carried out a comprehensive renovation of the forts, building 6 large forts: two on the south of the estuary, called "Wēi" (威-Might) and "Zhèn"(震-Thunder, Tremor, Quake), three to the north, "Hǎi"(海-sea), "Mén"(门-gate) "Gāo" (高-high), and the sixth, the "Shitoufeng" (石头缝-Stone Seam) Fort, was built on a small ridge on the northern shore. Each fort had three large guns and 20 small caliber guns. Forts were constructed of wood and brick with an external curtain of two feet of concrete, the layering designed to avoid spalling and minimize penetration by artillery rounds. The forts were around high, which located as they were in an exceedingly flat landscape, provided a critical vantage point.
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As the University of Massachusetts Amherst began to grow exponentially in the 1960s it was decided by the Board of Trustees that a large University Library would be needed for the Library System to make the transition into the future. The designer was Edward Durrell Stone who followed recommendations by a Boston library consultant who recommended that the University would require a building of nearly 310,000 square feet to meet with the growing demands of students. Ground was broken in April 1969 and the building was opened to the public in 1973, with an official dedication taking place in 1974. The building was ordered closed in September 1979 by then Chancellor Henry Koffler to address the serious issue of "spalling" where bits of brick from the facade on the exterior building would fall away.
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The building has fallen victim to several myths since its opening in 1973, the most popular of these being a variation of the "Sinking Library Myth," where the architect supposedly forgot to account for the weight of the books in the buildings designs, resulting in a settling of the building. This is a popular myth attributed to many university libraries and is untrue. The spalling of the bricks has also led to the common assumption that entire bricks fall away from the building, and invariably make contact with someone on the ground. While bits of material do occasionally break away, a full brick has never come away from the building, and a safety fence stands around the exterior of the building to keep passersby safe from the small chips which do.
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The NWSC was founded in 1985 in the root of the New Youth Study Society in Tsuen Wan which was a social group formed by activist Lau Shan-ching and other graduates from the University of Hong Kong aiming at providing education for workers and raise their social consciousness. However, as the government set up night courses for adults in the early 1980s, the number of workers attended to the society's courses dropped. The lecturers and students in the society decided to participate in the newly established District Board elections as the government introduced constitutional reform. Leung Yiu-chung, lecturer of the New Youth Study Society, led the Kwai Chung residents who were affected by concrete spalling and seepage in their public housing estates to demand solutions from the Housing Department.
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Detonation of this shaped charge turns it into a highly focused stream moving forward at extreme speeds. Like medium and high velocity solid shot armour piercing projectiles, these warheads also cause spalling on the interior of the vehicle's armour plate.(solid shot AP projectiles also strike other items inside the vehicle and transfer very large amounts of kinetic energy to the object(s) struck) A problem with shaped charge warheads is that if the ogive shaped liner is deep, the warhead will have more penetration but will form a smaller hole; smaller holes are associated with less damage inside the armoured vehicle than larger ones. Research on shaped charge warheads has shown a hole that is the size of a large coin on the outside of a tank turret will have the diameter of a pencil lead on the turret's inner face.
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If successful, it caused internal spalling of the armor plate, killing or injuring the tank crew inside.A 1941 issue of LIFE magazine showed a series of photo on how to make such antitank grenades along with X shaped slit trenches to protect the grenade thrower It is not known if this type of improvised anti-tank grenade was ever successfully employed in combat. By late 1940, the British had brought into production a purpose-built adhesive anti-tank grenade - known as the "sticky bomb"Ian Hogg "Grenades & Mortars" page 38 Ballantine Books 1974 \- that was not very successful in combat. When tanks overran entrenchments, hand grenades could be, and were, used by infantry as improvised anti-tank mines by placing or throwing them in the path of a tank in the hope of disabling a track.
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HMS New Zealands 'X' turret during the Battle of Jutland on display at the Torpedo Bay Navy Museum in Auckland. Caption reads, "The chunk of armour plating you see here was gouged out of X turret by a German shell." In anti-tank warfare, spalling through mechanical stress is an intended effect of high-explosive squash head (HESH) anti-tank shells and many other munitions which may not be powerful enough to pierce the armor of a target. The relatively soft warhead, containing or made of plastic explosive, flattens against the armor plating on tanks and other armored fighting vehicles (AFVs) and explodes, creating a shock wave that travels through the armor as a compression wave and is reflected at the free surface as a tensile wave breaking (tensile stress/strain fracture) the metal on the inside.
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The most well- known problem that can be avoided with proper heat-up is the dry-out spalling, which is often the result of excessive pressurization of entrapped steam after heating above the ebullition point of water. Similarly to the Portland concrete used in civil engineering, water is added to the refractory castables to provide workability and allow molding, pumping, shotcreting or other forms of placement. Water exists within castables in free or combined forms: while free water remains in the pores without reaction with the materials' other constituents, combined water is present usually in the hydrated compounds of cement. As a result, the energy needed for their removal is different and, while free water leaves for the atmosphere at higher rates from about 100 degrees Celsius, temperatures at the range of 150 to 300 degrees Celsius may be necessary to remove the combined water.
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The deck armor would be in three layers, consisting of STS laminated on STS for a total of STS weather deck, Class B laminated on STS for a total of second deck on the centerline, and a splinter deck; the outboard section would have Class B laminated on STS for a total of second deck and a splinter deck. Over the magazines, the splinter deck would be replaced by a STS third deck to protect from spalling. The main batteries were designed to have very heavy protection, with turret faces having Class B mounted on STS, resulting in thick laminated plate. The turret sides were to have up to Class A and turret roofs would have Class B. The barbettes would have been protected by up to Class A forward and aft, while the conning tower sides would have Class A.Garzke and Dulin, pp.
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As such, the lithologic characteristics of Cottonwood Limestone has made it one of the best building stones in the state and many past quarries, large and small, may be found on nearly every hill capped by this resource. Large, cut blocks of Cottonwood Limestone were famously used in historic, monumental buildings in the region, including churches, courthouses, and educational buildings; while rough stones of other limestones are more common in older, smaller homes and buildings. Its use in a building within its region can often be recognized by the use of large cut blocks, near-white or buff color, and showing abundant fossils or molds of “wheat-grain” shaped fusulinids coupled with general absence of spalling, splotchy black coloring from mold that find portions of the stone particularly favorable, and sculptured or protruding rough faces. Especially in older buildings close to a source, Cottonwood Limestone is sometimes paired with the Neva Limestone that is commonly exposed only 35 feet lower in the hills.
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Repair principles which do not improve the strength or performance of concrete beyond its original (undamaged) condition include: replacement and restoration of concrete after spalling and delamination; strengthening to restore structural load-bearing capacity; and increasing resistance to physical or mechanical attack. Repair principles for arresting and preventing further degradation include: control of anodic areas; cathodic protection, cathodic control; increasing resistivity; preserving or restoring passivity; increasing resistance to chemical attack; protection against ingress of adverse agents; and moisture control. Techniques for filling holes left by the removal of spalled or damaged concrete include: mortar repairs; flowing concrete repairs and sprayed concrete repairs. The filling of cracks, fissures or voids in concrete for structural purposes (restoration of strength and load-bearing capability), or non-structural reasons (flexible repairs where further movement is expected, or alternately to resist water and gas permeation) typically involves the injection of low viscosity resins or grouts based on epoxy, PU or acrylic resins, or micronised cement slurries.
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Historic England, the body responsible for listed buildings and other heritage assets in England, also publishes an annual "Heritage at Risk Register"—a survey of assets at risk through decay, damage and similar issues. The Anglican churches identified as at risk in the latest update were St Mary's Church in Cowes (affected by ingress of water), St James's Church in East Cowes (damp and structural problems), All Saints Church in Godshill (decaying stonework), St Thomas's Minster in Newport (decaying stonework and roofs), St John the Baptist's Church in Niton (decaying stonework, roof damage and ingress of water), St John's Church in Sandown (decaying stonework and ingress of water), the Church of St Saviour-on-the-Cliff in Shanklin (severe salt spalling of stonework and damage to windows), St Paul's Church in Shanklin (decaying stonework and timberwork and damage to windows) and Holy Trinity Church in Ventnor (decaying stonework). The Catholic Church of St Mary in Ryde is at risk due to water ingress.
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In the 1930s, as part of the extensive electrification project that brought New York–Washington and Harrisburg–Philadelphia intercity passenger and through-freight service under wire, the Schuylkill Branch was electrified from its 52nd Street Junction in Philadelphia to Haws Avenue in Norristown. With the surge in automobile sales and construction of extensions of the Pennsylvania Turnpike and the Interstate Highway System in Pennsylvania in the 1950s, the PRR eliminated commuter rail service in 1960 north of Manayunk, yielding Philadelphia, Norristown, and Reading commuter and through-passenger service to the rival Reading. With the bankruptcies of the PRR's successor Penn Central and the Reading Company, the creation of Conrail in 1976 led to the closure and abandonment of the Schuylkill Valley Branch north of Manayunk. SEPTA, which took over the rail line in 1983, operated the former Conrail service as its Cynwyd Line rail service until 1986, when spalling conditions on the Manayunk Bridge concrete viaduct connecting the line between Bala Cynwyd and Manayunk/Ivy Ridge warranted its closure, forcing SEPTA to scale back service its Cynwyd Station in Bala Cynwyd.
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An aerial view of Glen Canyon Dam from upstream, showing the spillways to lower left and right, the Glen Canyon Bridge and the electric switchyard to the right of the bridge. Glen Canyon's overall design was based on that of Hoover Dam – a massive concrete arch-gravity structure anchored in solid bedrock – with several significant changes. The engineers wanted the dam to rely predominantly on its arch shape to carry the tremendous pressure of the impounded water into the canyon walls instead of depending on the sheer weight of the structure to hold the reservoir back, as had been done at Hoover. However, the foundation rock at Glen Canyon consists of porous sandstone prone to spalling, in contrast to the stronger granite at the Hoover Dam site, forcing the Glen Canyon design to follow more conservative lines by greatly thickening the abutments, thus increasing the surface area through which the weight of dam and reservoir would be transmitted to the rock and relieving the pressure per square inch on the highly breakable cliffs.
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