Search results
Results from the WOW.Com Content Network
In engineering, span is the distance between two adjacent structural supports (e.g., two piers) of a structural member (e.g., a beam). Span is measured in the horizontal direction either between the faces of the supports ( clear span ) or between the centers of the bearing surfaces ( effective span ): [ 1 ]
Prestressed concrete is a method for overcoming the concrete's natural weakness in tension. [ 1 ] [ 2 ] It can be used to produce beams , floors or bridges with a longer span than is practical with ordinary reinforced concrete .
Waffle slabs are preferred for spans greater than 40 feet (12 m), because, for a given mass of concrete, they are much stronger than flat slabs, flat slabs with drop panels, two-way slabs, one-way slabs, and one-way joist slabs. [2] Section of a waffle slab including beam, ribs, and column head
Unlike an I-beam, a T-beam lacks a bottom flange, which carries savings in terms of materials, but at the loss of resistance to tensile forces. [5] T- beam designs come in many sizes, lengths and widths to suit where they are to be used (eg highway bridge, underground parking garage) and how they have to resist the tension, compression and shear stresses associated with beam bending in their ...
The Precast/Prestressed Concrete Institute (PCI) published the double tee load capacity calculation (load tables) for the first time in the PCI Design Handbook in 1971. The load tables use the code to identify double tee span type by using the width in feet, followed by "DT", followed by depth in inches, for example, 4DT14 is for 4-foot (1.2 m ...
Concrete has a very low coefficient of thermal expansion, and as it matures concrete shrinks. All concrete structures will crack to some extent, due to shrinkage and tension. Concrete which is subjected to long-duration forces is prone to creep. The density of concrete varies, but is around 2,400 kilograms per cubic metre (150 lb/cu ft). [1]
Grade beam. A grade beam or grade beam footing is a component of a building's foundation. It consists of a reinforced concrete beam that transmits the load from a bearing wall into spaced foundations such as pile caps or caissons. [1]
The concrete elements may be reinforced or prestressed. Such modern bridges include girder , plate girder , and box girder bridges, all types of beam bridges. Types of construction could include having many beams side by side with a deck across the top of them, to a main beam either side supporting a deck between them.