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Refractory Cement
Concrete is produced in a variety of compositions, finishes and performance characteristics to meet a wide range of needs. Mix design Modern concrete mix designs can be complex. The choice of a concrete mix depends on the need of the project both in terms of strength and appearance and in relation to local legislation and building codes. The design begins by determining the requirements of the concrete. These requirements take into consideration the weather conditions that the concrete will be exposed to in service, and the required design strength. The compressive strength of a concrete is determined by taking standard molded, standard-cured cylinder samples. Many factors need to be taken into account, from the cost of the various additives and aggregates, to the trade offs between the "slump" for easy mixing and placement and ultimate performance. A mix is then designed using cement (Portland or other cementitious material), coarse and fine aggregates, water and chemical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
I-355 At The Illinois Prairie Path
Interstate 355 (I-355), also known as the Veterans Memorial Tollway, is an Interstate Highway and toll road, tollway in the western and southwest suburbs of Chicago in the U.S. state of Illinois. Like most other toll roads in the northeastern portion of the state, I-355 is maintained by the Illinois State Toll Highway Authority (ISTHA). I-355 runs from Interstate 80 in Illinois, I-80 in New Lenox, Illinois, New Lenox north to Interstate 290 (Illinois), I-290 in Itasca, Illinois, Itasca, a distance of . With the exception of a expansion in 2009, from U.S. Route 34 in Illinois, U.S. Route 34 (US 34, Ogden Avenue) to 75th Street, the highway is six lanes wide for its entire length. The tollway authority opened I-355 as the North–South Tollway in 1989 to ease congestion on Illinois Route 53 (IL 53), a parallel two-lane state highway in central DuPage County, Illinois, DuPage County. Initially, I-355 ran from Interstate 55 in Illinois, I-55 north to I-290. The new highw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Segregation In Concrete
Segregation in concrete is a case of particle segregation in concrete applications, in which particulate solids tend to segregate by virtue of differences in the size, density, shape and other properties of particles of which they are composed. when the workability of concrete is high under pouring conditions, or the amount of mortar is larger than the void volume of coarse aggregate, or the particle size of aggregate is not ideal, excessive vibration can cause segregation bleeding or lighter weight Definition It is described by American Society for Testing and Materials as follows: "Segregation in concrete is commonly thought of as separation of some size groups of aggregates from cement mortar in isolated locations with corresponding deficiencies of these materials in other locations. Segregation results in proportions of the laid concrete being in variation with those designed. Segregation could result from internal factors such as concrete that is not proportioned properly an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lime (material)
Lime is an Inorganic compound, inorganic material composed primarily of calcium oxides and hydroxides. It is also the name for calcium oxide which is used as an industrial mineral and is made by heating calcium carbonate in a kiln. Calcium oxide can occur as a product of coal-seam fires and in altered limestone xenoliths in volcanic ejecta. The International Mineralogical Association recognizes lime as a mineral with the chemical formula of CaO. The word ''lime'' originates with its earliest use as building mortar and has the sense of ''sticking or adhering''. These materials are still used in large quantities in the manufacture of steel and as building and engineering materials (including limestone products, cement, concrete, and mortar (masonry), mortar), as chemical feedstocks, for sugar refining, and other uses. Lime industries and the use of many of the resulting products date from prehistoric times in both the Old World and the New World. Lime is used extensively for was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roman Concrete
Roman concrete, also called , was used in construction in ancient Rome. Like its modern equivalent, Roman concrete was based on a hydraulic-setting cement added to an aggregate. Many buildings and structures still standing today, such as bridges, reservoirs and aqueducts, were built with this material, which attests to both its versatility and its durability. Its strength was sometimes enhanced by the incorporation of pozzolanic ash where available (particularly in the Bay of Naples). The addition of ash prevented cracks from spreading. Recent research has shown that the incorporation of mixtures of different types of lime, forming conglomerate "clasts" allowed the concrete to self-repair cracks. Roman concrete was in widespread use from about 150 BC; some scholars believe it was developed a century before that. It was often used in combination with facings and other supports, and interiors were further decorated by stucco, fresco paintings, or coloured marble. Further inn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Accelerant
Accelerants, or accelerators, are substances that increase the rate of a natural or artificial chemical process. They play a major role in chemistry, as most chemical reactions can be hastened with an accelerant. Understanding accelerants is crucial in forensic science, engineering, and other fields where controlled chemical reactions are essential. Accelerants function by either altering a chemical bond, speeding up a chemical process, or changing the reaction conditions. Unlike catalysts, accelerants may be consumed during the process. They are commonly used in contexts such as fire investigation where they can indicate arson, in construction to speed the curing of building materials, and in sulfur vulcanization to produce rubber products such as tyres. In fire investigation, accelerants are often detected through laboratory analysis of fire debris. Various types of accelerants exist, including liquids, solids, and gases, each with specific properties and applications. Ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compressed Air
Compressed air is air kept under a pressure that is greater than atmospheric pressure. Compressed air in vehicle tires and shock absorbers are commonly used for improved traction and reduced vibration. Compressed air is an important medium for the transfer of energy in industrial processes and is used for power tools such as air hammer (fabrication), air hammers, Jackhammer, drills, power wrench, wrenches, and others, as well as to atomize paint, to operate air cylinders for automation, and can also be used to propel vehicles. Brakes applied by compressed air made large railway trains safer and more efficient to operate. Compressed air brakes are also found on large highway vehicles. Compressed air is used as a breathing gas by underwater diving, underwater divers. The diver may carry it in a high-pressure diving cylinder, or surface supplied diving, supplied from the surface at lower pressure through an air line or diver's umbilical. Similar arrangements are used in breathing ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunnel
A tunnel is an underground or undersea passageway. It is dug through surrounding soil, earth or rock, or laid under water, and is usually completely enclosed except for the two portals common at each end, though there may be access and ventilation openings at various points along the length. A pipeline differs significantly from a tunnel, though some recent tunnels have used immersed tube construction techniques rather than traditional tunnel boring methods. A tunnel may be for foot or vehicular road traffic, for rail traffic, or for a canal. The central portions of a rapid transit network are usually in the tunnel. Some tunnels are used as sewers or aqueducts to supply water for consumption or for hydroelectric stations. Utility tunnels are used for routing steam, chilled water, electrical power or telecommunication cables, as well as connecting buildings for convenient passage of people and equipment.Salazar, Waneta. ''Tunnels in Civil Engineering''. Delhi, India : Wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plasticizer
A plasticizer ( UK: plasticiser) is a substance that is added to a material to make it softer and more flexible, to increase its plasticity, to decrease its viscosity, and/or to decrease friction during its handling in manufacture. Plasticizers are commonly added to polymers and plastics such as PVC, either to facilitate the handling of the raw material during fabrication, or to meet the demands of the end product's application. Plasticizers are especially key to the usability of polyvinyl chloride (PVC), the third most widely used plastic. In the absence of plasticizers, PVC is hard and brittle; with plasticizers, it is suitable for products such as vinyl siding, roofing, vinyl flooring, rain gutters, plumbing, and electric wire insulation/coating. Plasticizers are also often added to concrete formulations to make them more workable and fluid for pouring, thus allowing the water contents to be reduced. Similarly, they are often added to clays, stucco, solid rocket fuel, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transportation In The United States
The vast majority of passenger travel in the United States occurs by automobile for shorter distances and airplane or railroad for longer distances. Most cargo in the U.S. is transported by, in descending order, railroad, truck, pipeline, or boat; air shipping is typically used only for perishables and premium express shipments. Transportation is the largest source of greenhouse gas emissions by the United States, greenhouse gas emissions in the United States. Ownership and jurisdiction The overwhelming majority of roads in the United States are owned and maintained by state and local governments. Federally maintained roads are generally found only on federal lands (such as List of National Parks of the United States, national parks) and at federal facilities (like military bases). The Interstate Highway System is partly funded by the federal government but owned and maintained by individual state governments. There are a few private highways in the United States, which use t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Formwork
Formwork is Molding (process), molds into which concrete or similar materials are either precast concrete, precast or cast-in-place concrete, cast-in-place. In the context of concrete construction, the falsework supports the shuttering molds. In specialty applications formwork may be permanently incorporated into the final structure, adding insulation or helping reinforce the finished structure. Types Formwork may be made of wood, metal, plastic, or composite materials: #''Traditional timber formwork''. The formwork is built on site out of timber and plywood or moisture-resistant particleboard. It is easy to produce but time-consuming for larger structures, and the plywood facing has a relatively short lifespan. It is still used extensively where the labour costs are lower than the costs for procuring reusable formwork. It is also the most flexible type of formwork, so even where other systems are in use, complicated sections may use it. #''Engineered Formwork System''. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wear And Tear
Wear and tear is damage that naturally and inevitably occurs as a result of normal wear or aging. It is used in a legal context for such areas as warranty contracts from manufacturers, which usually stipulate that damage from ''wear and tear'' will not be covered. Wear and tear is a form of depreciation, which is assumed to occur even when an item is used competently and with care and proper maintenance. For example, repeated impacts may cause stress to a hammer's head. This stress is impossible to prevent in the normal use of the tool for its designed task, and any attempt to avert it impedes its functionality. At the same time, it is expected that the normal use of a hammer will not break it beyond repair during a reasonable life cycle. If an object's restoration is impossible, it is regarded as consumable. Parts that are designed to wear inside a machine—e.g., bearings and O-rings—are intended to be replaced with new ones; consumables like paper, cardboard, fabrics, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vibrator (mechanical)
A vibrator is a mechanical device to generate vibrations. The vibration is often generated by an electric motor with an unbalanced mass on its driveshaft. There are many different types of vibrator. Typically, they are components of larger products such as smartphones, pagers, or video game controllers with a "rumble" feature. Vibrators as components When smartphones and pagers vibrate, the vibrating alert is produced by a small component that is built into the phone or pager. Many older, non-electronic buzzers and doorbells contain a component that vibrates for the purpose of producing a sound. Tattoo machines and some types of electric engraving tools contain a mechanism that vibrates a needle or cutting tool. Aircraft stick shakers use a vibrating mechanism attached to the pilots' control yokes to provide a tactile warning of an impending aerodynamic stall. Eccentric rotating mass (ERM) vibrators work by rotating a deliberately unbalanced weight, so the weight is eccentr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
