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Glossary Of Prestressed Concrete Terms
This page is a glossary of Prestressed concrete terms. A B C D E F G H I J K L M N O P Q R S T U V W Y See also * Cable-stayed bridge * Cantilever bridge * Concrete * Beam (structure), Concrete beam * Concrete slab * Construction * Glossary of engineering * Glossary of civil engineering * Glossary of structural engineering * Incremental launch, Incremental launch method * Precast concrete * Prestressed concrete * Prestressed structure * Reinforced concrete * Segmental bridge Prestressing Wedges References [Baidu] |
Prestressed Concrete
Prestressed concrete is a form of concrete used in construction. It is substantially "prestressed" ( compressed) during production, in a manner that strengthens it against tensile forces which will exist when in service. Post-tensioned concreted is "structural concrete in which internal stresses have been introduced to reduce potential tensile stresses in the concrete resulting from loads." This compression is produced by the tensioning of high-strength "tendons" located within or adjacent to the concrete and is done to improve the performance of the concrete in service. Tendons may consist of single wires, multi-wire strands or threaded bars that are most commonly made from high-tensile steels, carbon fiber or aramid fiber. The essence of prestressed concrete is that once the initial compression has been applied, the resulting material has the characteristics of high-strength concrete when subject to any subsequent compression forces and of ductile high-strength steel when sub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tendon Extension
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability to withstand significant amounts of tension. Tendons are similar to ligaments; both are made of collagen. Ligaments connect one bone to another, while tendons connect muscle to bone. Structure Histologically, tendons consist of dense regular connective tissue. The main cellular component of tendons are specialized fibroblasts called tendon cells (tenocytes). Tenocytes synthesize the extracellular matrix of tendons, abundant in densely packed collagen fibers. The collagen fibers are parallel to each other and organized into tendon fascicles. Individual fascicles are bound by the endotendineum, which is a delicate loose connective tissue containing thin collagen fibrils and elastic fibres. Groups of fascicles are bounded by the epitenon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Young's Modulus
Young's modulus E, the Young modulus, or the modulus of elasticity in tension or compression (i.e., negative tension), is a mechanical property that measures the tensile or compressive stiffness of a solid material when the force is applied lengthwise. It quantifies the relationship between tensile/compressive stress \sigma (force per unit area) and axial strain \varepsilon (proportional deformation) in the linear elastic region of a material and is determined using the formula: E = \frac Young's moduli are typically so large that they are expressed not in pascals but in gigapascals (GPa). Example: * Silly Putty (increasing pressure: length increases quickly, meaning tiny E) * Aluminum (increasing pressure: length increases slowly, meaning high E) Higher Young's modulus corresponds to greater (lengthwise) stiffness. Although Young's modulus is named after the 19th-century British scientist Thomas Young, the concept was developed in 1727 by Leonhard Euler. The first exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yield (engineering)
In materials science and engineering, the yield point is the point on a stress-strain curve that indicates the limit of elastic behavior and the beginning of plastic behavior. Below the yield point, a material will deform elastically and will return to its original shape when the applied stress is removed. Once the yield point is passed, some fraction of the deformation will be permanent and non-reversible and is known as plastic deformation. The yield strength or yield stress is a material property and is the stress corresponding to the yield point at which the material begins to deform plastically. The yield strength is often used to determine the maximum allowable load in a mechanical component, since it represents the upper limit to forces that can be applied without producing permanent deformation. In some materials, such as aluminium, there is a gradual onset of non-linear behavior, making the precise yield point difficult to determine. In such a case, the offset yi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wire
Overhead power cabling. The conductor consists of seven strands of steel (centre, high tensile strength), surrounded by four outer layers of aluminium (high conductivity). Sample diameter 40 mm A wire is a flexible strand of metal. Wire is commonly formed by drawing the metal through a hole in a die or draw plate. Wire gauges come in various standard sizes, as expressed in terms of a gauge number. Wires are used to bear mechanical loads, often in the form of wire rope. In electricity and telecommunications signals, a "wire" can refer to an electrical cable, which can contain a "solid core" of a single wire or separate strands in stranded or braided forms. Usually cylindrical in geometry, wire can also be made in square, hexagonal, flattened rectangular, or other cross-sections, either for decorative purposes, or for technical purposes such as high-efficiency voice coils in loudspeakers. Edge-wound coil springs, such as the Slinky toy, are made of special flatten ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wire Rope
Steel wire rope (right hand lang lay) Wire rope is several strands of metal wire twisted into a helix forming a composite ''rope'', in a pattern known as ''laid rope''. Larger diameter wire rope consists of multiple strands of such laid rope in a pattern known as ''cable laid''. In stricter senses, the term ''wire rope'' refers to a diameter larger than , with smaller gauges designated cable or cords. Initially wrought iron wires were used, but today steel is the main material used for wire ropes. Historically, wire rope evolved from wrought iron chains, which had a record of mechanical failure. While flaws in chain links or solid steel bars can lead to catastrophic failure, flaws in the wires making up a steel cable are less critical as the other wires easily take up the load. While friction between the individual wires and strands causes wear over the life of the rope, it also helps to compensate for minor failures in the short run. Wire ropes were developed starting with mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stressing Stool
Stressing is a rail engineering process. It is used to prevent heat and cold tension after installation of continuous welded rail (CWR). Environmental heat causes CWR to expand and therefore can cause the fixed track to buckle. Environmental cold can lead to the contraction of the fixed railway track causing brittleness and cracks. Before it is installed, the rail is altered by stretching with hydraulic tensors or heated to its stress-free temperature to make these dangerous problems less likely. Background Railway steel contracts at low temperatures and expands at high temperatures.Bibel G''Train Wreck: The Forensics of Rail Disasters''JHU Press, 2012 In extreme cold, a length of CWR suffers tensile stress. This stress can cause railway steel to fracture. In extreme heat, a length of CWR suffers compressive stress. This type of stress can cause sun kink where a length of a railway buckles laterally (sideways). Other factors that affect CWR condition include the state of the tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jack Ram
Jack Ram (born 14 January 1987) is a Tongan professional rugby union footballer. He plays for New England Free Jacks of Major League Rugby (MLR). He represented the Tonga sevens team and Tonga national rugby teams between 2009 and 2015. Early life Ram's father, Samuel Santa Ram is a Fiji-Indian and is from Tavua. His mother is a Tongan who his father met and married in Australia. Ram was born in Australia, his parents moved to Tonga when he was 3 to start a business there. He plays club rugby for Lavengamalie Rugby Club. He represented the Tongan under-19 team in 2006. Career He joined Lavengamalie Rugby Club in 2005. In 2009, he played in the Pacific Rugby Cup for Tautahi Gold. In the same year, he was recruited into the Tonga sevens team. One of his biggest victory came in 2012 when he scored a try to help Tonga 7's beat the Fiji sevens side for the first time in history at the 2012 Wellington Sevens. He joined the Kerikeri rugby club in 2011. He represented Northl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydraulic Pump
Hydraulic pumps are used in hydraulic drive systems and can be hydrostatic or hydrodynamic. A hydraulic pump is a mechanical source of power that converts mechanical power into hydraulic energy ( hydrostatic energy i.e. flow, pressure). It generates flow with enough power to overcome pressure induced by the load at the pump outlet. When a hydraulic pump operates, it creates a vacuum at the pump inlet, which forces liquid from the reservoir into the inlet line to the pump and by mechanical action delivers this liquid to the pump outlet and forces it into the hydraulic system. Hydrostatic pumps are positive displacement pumps while hydrodynamic pumps can be fixed displacement pumps, in which the displacement (flow through the pump per rotation of the pump) cannot be adjusted, or variable displacement pumps, which have a more complicated construction that allows the displacement to be adjusted. Hydrodynamic pumps are more frequent in day-to-day life. Hydrostatic pumps of various types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tendon Profile
A tendon or sinew is a tough, high-tensile-strength band of dense fibrous connective tissue that connects muscle to bone. It is able to transmit the mechanical forces of muscle contraction to the skeletal system without sacrificing its ability to withstand significant amounts of tension. Tendons are similar to ligaments; both are made of collagen. Ligaments connect one bone to another, while tendons connect muscle to bone. Structure Histologically, tendons consist of dense regular connective tissue. The main cellular component of tendons are specialized fibroblasts called tendon cells (tenocytes). Tenocytes synthesize the extracellular matrix of tendons, abundant in densely packed collagen fibers. The collagen fibers are parallel to each other and organized into tendon fascicles. Individual fascicles are bound by the endotendineum, which is a delicate loose connective tissue containing thin collagen fibrils and elastic fibres. Groups of fascicles are bounded by the epitenon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macalloy
McCalls Special Products Ltd is a British manufacturer of steel bar and cable components for tensioned concrete, ground anchors, curtain walling, and steel structures. It operates under the Macalloy brand and claims to be a world leader in that market. Macalloy's work supports landmarks including the Sphere at the Academy Museum of Motion Pictures, VTB Stadium, Stade Roland Garros, Tottenham Hotspur Stadium, Soccer City Stadium, Marina Bay Sands, Jewel Changi Airport, Forth Road Bridge, and Burj Al Arab. , of the company's products are exported. History McCall and Company Ltd was founded in 1921 by T H McCall, Edwin Llwewllyn Raworth, and C W Hamilton, on Queens Street, Sheffield to supply steel rebar for concrete contractors. In 1927, it moved to former railway engineering sheds on Nunnery Lane for two years then again to its steel supplier, United Bar Strip Mills' Templeborough Steelworks. In 1948, the firm began to manufacture bars for post tensioned concrete. Thes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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