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Shell Pavement Design Method
The Shell pavement design method was used in many countries for the design of new pavements made of asphalt. First published in 1963, it was the first mechanistic design method, providing a procedure that was no longer based on codification of historic experience but instead that permitted computation of strain levels at key positions in the pavement. By analyzing different proposed constructions (layer materials and thicknesses), the procedure allowed a designer to keep the tensile strain at the bottom of the asphalt at a level less than a critical value and to keep the vertical strain at the top of the subgrade less than another critical value. With these two strains kept, respectively, within the design limits, premature fatigue failure in the asphalt and rutting of the pavement would be precluded. Relationships linking strain values to fatigue and rutting permitted a user to design a pavement able to carry almost any desired number of transits of standard wheel loads. In such ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Countries
A country is a distinct part of the Earth, world, such as a state (polity), state, nation, or other polity, political entity. When referring to a specific polity, the term "country" may refer to a sovereign state, List of states with limited recognition, state with limited recognition, Country (other)#Administrative divisions, constituent country, or dependent territory. Most sovereign states, but not all countries, are members of the United Nations. There is no universal agreement on List of sovereign states, the number of "countries" in the world, since several states have disputed sovereignty status or limited recognition, and a number of non-sovereign entities are commonly considered countries. The definition and usage of the word "country" are flexible and have changed over time. ''The Economist'' wrote in 2010 that "any attempt to find a clear definition of a country soon runs into a thicket of exceptions and anomalies." Areas much smaller than a political entit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Sidewalk
A sidewalk (North American English), pavement (British English, South African English), or footpath (Hiberno-English, Irish English, Indian English, Australian English, New Zealand English) is a path along the side of a road. Usually constructed of concrete, pavers, brick, stone, or asphalt, it is designed for pedestrians. A sidewalk is normally higher than the carriageway, roadway, and separated from it by a curb. There may also be a Road verge, planted strip between the sidewalk and the roadway and between the roadway and the adjacent land. Terminology The preferred term for a pedestrian path beside a road varies based on region. The term "sidewalk" is preferred in most of the United States and Canada. The term "pavement" is more common in the United Kingdom and some other members of the Commonwealth of Nations, as well as parts of the Mid-Atlantic United States such as Philadelphia and parts of New Jersey. Australia, New Zealand, and many other Commonwealth countr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Asphalt Concrete
Asphalt concrete (commonly called asphalt, blacktop, or pavement in North America, and Tarmacadam, tarmac or bitumen macadam in the United Kingdom and the Republic of Ireland) is a composite material commonly used to surface road surface, roads, parking lots, airports, and the core of embankment dams. Asphalt mixtures have been used in pavement construction since the nineteenth century. It consists of Construction aggregate, mineral aggregate Binder (material), bound together with bitumen (a substance also independently known as asphalt, Pitch (resin), pitch, or tar), laid in layers, and compacted. The American English terms ''asphalt'' (or ''asphaltic'') ''concrete'', ''bituminous asphalt concrete'', and ''bituminous mixture'' are typically used only in engineering and construction documents, which define concrete as any composite material composed of mineral aggregate adhered with a binder. The abbreviation, ''AC'', is sometimes used for ''asphalt concrete'' but can also denot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Structural Road Design
Structural road design aims to ensure the road is strong enough for the expected number of vehicles in a certain number of years. The input of a calculation is the number expected of vehicles (e.g. 10,000,000) divided in groups (e.g. trucks, vans, cars) and the number of years that the road has to function before the road structure has to be fully renewed (e.g. 20 years). The given example of 20 years does not mean that there is no maintenance during this period. There is a certain amount of maintenance, but it can be scheduled and is low. For asphalt, the Shell pavement design method is often used. See also * Road traffic control * Geometric design of roads *Road surface A road surface (British English) or pavement (North American English) is the durable surface material laid down on an area intended to sustain vehicular or foot traffic, such as a road or walkway. In the past, gravel road surfaces, macadam, ... References External links *https://web.archive.org/we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Soil
Soil, also commonly referred to as earth, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by restricting the former term specifically to displaced soil. Soil consists of a solid collection of minerals and organic matter (the soil matrix), as well as a porous phase that holds gases (the soil atmosphere) and water (the soil solution). Accordingly, soil is a three- state system of solids, liquids, and gases. Soil is a product of several factors: the influence of climate, relief (elevation, orientation, and slope of terrain), organisms, and the soil's parent materials (original minerals) interacting over time. It continually undergoes development by way of numerous physical, chemical and biological processes, which include weathering with associated erosion. Given its complexity and strong internal connectedness, soil ecologists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Parameter
A parameter (), generally, is any characteristic that can help in defining or classifying a particular system (meaning an event, project, object, situation, etc.). That is, a parameter is an element of a system that is useful, or critical, when identifying the system, or when evaluating its performance, status, condition, etc. ''Parameter'' has more specific meanings within various disciplines, including mathematics, computer programming, engineering, statistics, logic, linguistics, and electronic musical composition. In addition to its technical uses, there are also extended uses, especially in non-scientific contexts, where it is used to mean defining characteristics or boundaries, as in the phrases 'test parameters' or 'game play parameters'. Modelization When a system theory, system is modeled by equations, the values that describe the system are called ''parameters''. For example, in mechanics, the masses, the dimensions and shapes (for solid bodies), the densities and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Foundation (engineering)
In engineering, a foundation is the element of a structural engineering, structure which connects it to the ground or more rarely, water (as with Floating building, floating structures), transferring force, loads from the structure to the ground. Foundations are generally considered either Shallow foundation, shallow or Deep foundation, deep. Foundation engineering is the application of soil mechanics and rock mechanics (geotechnical engineering) in the design of foundation elements of structures. Purpose Foundations provide the structure's stability from the ground: * To distribute the weight of the structure over a large area in order to avoid overloading the underlying soil (possibly causing unequal settlement). * To anchor the structure against natural forces including earthquakes, floods, droughts, frost heaves, tornadoes and wind. * To provide a level surface for construction. * To anchor the structure deeply into the ground, increasing its stability and preventing over ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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AASHTO
The American Association of State Highway and Transportation Officials (AASHTO) is a standards setting body which publishes specifications, test quality control, protocols, and guidelines that are used in highway design and construction throughout the United States. Despite its name, the association represents not only highways but air, rail, water, and public transportation as well. Although AASHTO sets transportation standards and policy for the United States as a whole, AASHTO is not an agency of the federal government; rather it is an organization of the states themselves. Policies of AASHTO are not federal laws or policies, but rather are ways to coordinate state laws and policies in the field of transportation. Purpose The American Association of State Highway Officials (AASHO) was founded on December 12, 1914. Its name was changed to American Association of State Highway and Transportation Officials on November 13, 1973. The name change reflects a broadened scope to co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Road Surface
A road surface (British English) or pavement (North American English) is the durable surface material laid down on an area intended to sustain vehicular or foot traffic, such as a road or walkway. In the past, gravel road surfaces, macadam, hoggin, cobblestone and granite setts were extensively used, but these have mostly been replaced by asphalt or concrete laid on a compacted base course. Asphalt mixtures have been used in pavement construction since the beginning of the 20th century and are of two types: metalled (hard-surfaced) and unmetalled roads. Metalled roadways are made to sustain vehicular load and so are usually made on frequently used roads. Unmetalled roads, also known as gravel roads or dirt roads, are rough and can sustain less weight. Road surfaces are frequently marked to guide traffic. Today, permeable paving methods are beginning to be used for low-impact roadways and walkways to prevent flooding. Pavements are crucial to countries such as United St ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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Pavements
Pavement(s) or paving may refer to: Surfacing * Road surface, the durable surfacing of roads and walkways * Sidewalk, a walkway along the side of a road, called a pavement in British English * Asphalt concrete, a common form of road surface * Cool pavement, pavement that delivers higher solar reflectance than conventional dark pavement * Crazy paving, a means of hard-surfacing used outdoors * Nicolson pavement, a road surface material consisting of wooden blocks * Pavers (flooring), an outdoor floor done in blocks * Permeable paving, paving that enables stormwater to flow through it or between gaps * Portuguese pavement, the traditional paving used in most pedestrian areas in Portugal * Resin-bound paving, a mixture of aggregate stones and resin used to pave footpaths, driveways, etc. * Tactile paving, textured ground surface indicators to assist vision-impaired pedestrians * Whitetopping, the covering of an existing asphalt pavement with a layer of Portland cement concret ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |