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Recycled Concrete
__FORCETOC__ Concrete recycling is the use of rubble from demolished concrete structures. Recycling is cheaper and more ecological than trucking rubble to a landfill. Crushed rubble can be used for road gravel, revetments, retaining walls, landscaping gravel, or raw material for new concrete. Large pieces can be used as bricks or slabs, or incorporated with new concrete into structures, a material called urbanite. Circular economy Concrete is an excellent material with which to make long-lasting and energy-efficient buildings. However, even with good design, human needs change and potential waste will be generated.World Business Council for Sustainable Development, "Cement Sustainability Initiative, The Cement Sustainability Initiative – Recycling concrete", available online at: www.wbcsdcement.org (last access on October 5th 2021) Concrete may be considered waste according to the European Commission decision of 2014/955/EU for the List of Waste under the codes: 17 (construct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Waste
Waste are unwanted or unusable materials. Waste is any substance discarded after primary use, or is worthless, defective and of no use. A by-product, by contrast is a joint product of relatively minor Value (economics), economic value. A waste product may become a by-product, joint product or resource through an invention that raises a waste product's value above zero. Examples include municipal solid waste (household trash/refuse), hazardous waste, wastewater (such as sewage, which contains bodily wastes (feces and urine) and surface runoff), radioactive waste, and others. Definitions What constitutes waste depends on the eye of the beholder; one person's waste can be a resource for another person. Though waste is a physical object, its generation is a physical and psychological process. The definitions used by various agencies are as below. United Nations Environment Program According to the Basel Convention on the Control of Transboundary Movements of Hazardous Wastes a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base Course
The base course or basecourse in pavements is a layer of material in an asphalt roadway, race track, riding arena, or sporting field. It is located under the surface layer consisting of the '' wearing course'' and sometimes an extra ''binder course''. If there is a sub-base course, the base course is constructed directly above this layer. Otherwise, it is built directly on top of the subgrade. Typical base course thickness ranges from and is governed by underlying layer properties. Generally made of a construction aggregate, it is spread and compacted to at least 95% relative compaction, thus providing a stable foundation for additional layers of material. Aggregate base (AB) is typically a mix of different sizes of crushed rock '' Aggregate Base, Class 2'', is used in roadways and consists of rock particles of size and less. An aggregate is normally made from newly quarried rock, or it is sometimes allowed to be made from recycled asphalt concrete and/or Portland cement concr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hostile Architecture
Hostile architecture is an Urban design, urban-design strategy that uses elements of the built environment to purposefully guide behavior. It often targets people who use or rely on public space more than others, such as youth, poor people, and homeless people, by restricting the physical behaviours they can engage in. The term ''hostile architecture'' is often associated with items like "anti-homeless spikes" – studs embedded in flat surfaces to make sleeping on them uncomfortable and impractical. This form of architecture is most commonly found in densely populated and urban areas. Other measures include sloped window sills to stop people sitting; benches with armrests positioned to stop people lying on them; water sprinklers that spray intermittently; and Waste container, public trash bins with inconveniently small mouths to prevent the insertion of bulky wastes. Hostile architecture is also employed to deter skateboarding, BMXing, inline skating, littering, loitering, public ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retaining Wall
Retaining walls are relatively rigid walls used for supporting soil laterally so that it can be retained at different levels on the two sides. Retaining walls are structures designed to restrain soil to a slope that it would not naturally keep to (typically a steep, near-vertical or vertical slope). They are used to bound soils between two different elevations often in areas of inconveniently steep terrain in areas where the landscape needs to be shaped severely and engineered for more specific purposes like hillside farming or roadway overpasses. A retaining wall that retains soil on the backside and water on the frontside is called a seawall or a bulkhead. Definition A retaining wall is designed to hold in place a mass of earth or the like, such as the edge of a terrace or excavation. The structure is constructed to resist the lateral pressure of soil when there is a desired change in ground elevation that exceeds the angle of repose of the soil. A basement wall is thus one k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecology Block
An ecology block, also known as an eco-block or ecoblock, is a type of recycled concrete block used to make retaining walls. Ecology blocks are manufactured using concrete left over from other construction processes. A cross-section of an eco-block typically measures square, with block lengths ranging from to . One block weighs between and . Uses Ecology blocks are marketed for construction of retaining walls; they have grooves on the top and bottom to facilitate vertical stacking. They are used for storage of bulk materials and other modular construction projects where permanent structures are not needed. They have also been used as a temporary fix for a critical road in Skagit County, Washington, that had been damaged by floods. Following the September 11 attacks, at the Hanford Site's Plutonium Finishing Plant, eco-blocks and Jersey barriers were used to create a barrier against vehicular attack. The Seattle Police Department used eco-blocks to construct walls around the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riprap
Riprap (in North American English), also known as rip rap, rip-rap, shot rock, rock armour (in British English) or rubble, is human-placed rock or other material used to protect shoreline structures against scour and water, wave, or ice erosion. Riprap is used to armor shorelines, streambeds, bridge abutments, foundational infrastructure supports and other shoreline structures against erosion. Common rock types used include granite and modular concrete blocks. Rubble from building and paving demolition is sometimes used, as well as specifically designed structures called ''tetrapods'' or similar concrete blocks. Riprap is also used underwater to cap immersed tubes sunken on the seabed to be joined into an undersea tunnel. Environmental effects Sediment effects Riprap causes morphological changes in the riverbeds they surround. One such change is the reduction of sediment settlement in the river channel, which can lead to scouring of the river bed as well as coarser sedime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quarry
A quarry is a type of open-pit mining, open-pit mine in which dimension stone, rock (geology), rock, construction aggregate, riprap, sand, gravel, or slate is excavated from the ground. The operation of quarries is regulated in some jurisdictions to manage their safety risks and reduce their environmental impact. The word ''quarry'' can also include the underground quarrying for stone, such as Bath stone. History For thousands of years, only hand tools had been used in quarries. In the eighteenth century, the use of drilling and blasting operations was mastered. Types of rock Types of rock extracted from quarries include: *Chalk *China clay *Scoria, Cinder *Clay *Coal *Construction aggregate (sand and gravel) *Coquina *Diabase *Gabbro *Granite *Gritstone *Gypsum *Limestone *Marble *Ores *Phosphate rock *Quartz *Sandstone *Slate *Travertine Methods of quarrying The method of removal of stones from their natural bed by using different operations is called quarryin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crusher
A crusher is a machine designed to reduce large rocks into smaller rocks, gravel, sand or rock dust. Crushers may be used to reduce the size, or change the form, of waste materials so they can be more easily disposed of or recycled, or to reduce the size of a solid mix of raw materials (as in rock ore), so that pieces of different composition can be differentiated. Crushing is the process of transferring a force amplified by mechanical advantage through a material made of molecules that bond together more strongly, and resist deformation more, than those in the material being crushed do. Crushing devices hold material between two parallel or tangent solid surfaces, and apply sufficient force to bring the surfaces together to generate enough energy within the material being crushed so that its molecules separate from (fracturing), or change alignment in relation to (deformation), each other. The earliest crushers were hand-held stones, where the weight of the stone provided a boost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aggregate (composite)
Aggregate is the component of a composite material that resists compressive stress and provides bulk to the material. For efficient filling, aggregate should be much smaller than the finished item, but have a wide variety of sizes. Aggregates are generally added to lower the amount of binders needed and to increase the strength of composite materials. Sand and gravel are used as construction aggregate with cement to make concrete and increase its mechanical strength. Aggregates make up 60-80% of the volume of concrete and 70-85% of the mass of concrete. Comparison to fiber composites ''Aggregate composites'' are easier to fabricate, and more predictable in their finished properties, than '' fiber composites''. Fiber orientation and continuity can have a large effect, but can be difficult to control and assess. Aggregate materials are generally less expensive. Mineral aggregates are found in nature and can often be used with minimal processing. Not all composite materials i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnet
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, cobalt, etc. and attracts or repels other magnets. A permanent magnet is an object made from a material that is magnetized and creates its own persistent magnetic field. An everyday example is a refrigerator magnet used to hold notes on a refrigerator door. Materials that can be magnetized, which are also the ones that are strongly attracted to a magnet, are called ferromagnetic (or ferrimagnetic). These include the elements iron, nickel and cobalt and their alloys, some alloys of rare-earth metals, and some naturally occurring minerals such as lodestone. Although ferromagnetic (and ferrimagnetic) materials are the only ones attracted to a magnet strongly enough to be commonly considered magnetic, all other substances respond weakly to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rebar
Rebar (short for reinforcement bar or reinforcing bar), known when massed as reinforcing steel or steel reinforcement, is a tension device added to concrete to form ''reinforced concrete'' and reinforced masonry structures to strengthen and aid the concrete under tension. Concrete is strong under compression, but has low tensile strength. Rebar usually consists of steel bars which significantly increase the tensile strength of the structure. Rebar surfaces feature a continuous series of ribs, lugs or indentations to promote a better bond with the concrete and reduce the risk of slippage. The most common type of rebar is carbon steel, typically consisting of hot-rolled round bars with deformation patterns embossed into its surface. Steel and concrete have similar coefficients of thermal expansion, so a concrete structural member reinforced with steel will experience minimal differential stress as the temperature changes. Other readily available types of rebar are manufacture ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
