Frozen materials should never be used. Concrete should not be cast on a frozen subgrade, and ice must be removed from forms before concreting .Concrete allowed to freeze wet, before or during early curing, may be seriously damaged. Furthermore, temperatures should be kept above 40 F for any appreciable curing (strength gain) for the concreting […]
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Contractors should understand the process of rebar inspection , whether the inspection is done by their own forces or by an inspector re p resenting the owner or building official. The goal of inspection or quality – control programs is to ensure that contract documents and buildingcodes are followed. The programs also ensure structural safety
Currently, open-web steel joists are still relatively small, parallel-chord trusses, but hot-rolled steel shapes usually make up the components of design of open web steel joist . (For a time, cold-formed steel shapes were preferred for chords to utilize higher working stresses available in cold-formed sections of ordinary carbon-steel grades. Unfavorable fabrication costs, however, led
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In general, all types of beam connections are classified as either framed or seated. In the framed type, the beam is connected to the supporting member with fittings (short angles are common) attached to the beam web. With seated connections, the ends of the beam rest on a ledge or seat, in much the same
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There are many different types of foundation excavations performed during the construction of a project. For example, soil may be excavated from the cut or borrow area and then used as fill . Another example is the excavation of a shear key or buttress that will be used to stabilize a slope or landslide. Other
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A shallow foundations are often selected when the structural load will not cause excessive settlement of the underlying soil layers. In general, shallow foundations are more economical to construct than deep foundations. Common types of shallow foundations are listed in Table 6.2 and described below Spread Footings, Combined Footings, and Strip Footings. These types of
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Temporary retaining walls are often used during construction, such as for the support of the sides of an excavation that is made below-grade in order to construct the building foundation. If the temporary retaining wall has the ability to develop the active wedge, then the basic active earth pressure principles described in the previous sections
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Portland cement, the most common of the modern cements, is made by carefully blending selected raw materials to produce a finished material meeting the requirements of ASTM C150 for one of eight specific cement types. Four major compounds [lime (CaO), iron (Fe2O3), silica (SiO2), and alumina (Al2O3)] and two minor compounds [gypsum (CaSO4 2H2O)
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Buildings should be designed to have protection against earthquakes in minor earthquakes without damage, because they may occur almost everywhere. For major earthquakes, it may not be economical to prevent all damage but collapse should be precluded. Because an earthquake and a high wind are not likely to occur simultaneously, building codes usually do not
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The simplest major building systems consists of only two components. One component is a floor, a flat, horizontal surface on which human activities can take place. The other component is an enclosure that extends over the floor and generally also around it to provide shelter from the weather for human activities. The ground may serve
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