prestressed concrete

(redirected from Bonded post-tensioned concrete)
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Related to Bonded post-tensioned concrete: Prestressed concrete, Pretensioned concrete

prestressed concrete

[¦prē′strest ′kän‚krēt]
(materials)
Concrete compressed with heavily loaded wires or bars to reduce or eliminate cracking and tensile forces.

prestressed concrete

A process of anchoring steel rods into the ends of forms, then stretching them before the concrete is poured, putting them under tension. When the concrete hardens, they spring back to their original shape, providing additional strength. See also: Concrete

Prestressed concrete

Concrete with stresses induced in it before use so as to counteract stresses that will be produced by loads. Prestress is most effective with concrete, which is weak in tension, when the stresses induced are compressive. One way to produce compressive prestress is to place a concrete member between two abutments, with jacks between its ends and the abutments, and to apply pressure with the jacks. The most common way is to stretch steel bars or wires, called tendons, and to anchor them to the concrete; when they try to regain their initial length, the concrete resists and is prestressed. The tendons may be stretched with jacks or by electrical heating.

Prestressed concrete is particularly advantageous for beams. It permits steel to be used at stresses several times larger than those permitted for reinforcing bars. It permits high-strength concrete to be used economically, for in designing a member with reinforced concrete, all concrete below the neutral axis is considered to be in tension and cracked, and therefore ineffective, whereas the full cross section of a prestressed concrete beam is effective in bending. See Reinforced concrete, Stress and strain

prestressed concrete

Concrete in which internal stresses are introduced of such magnitude and distribution that the tensile stresses resulting from the service loads are counteracted to a desired degree; in reinforced concrete the prestress commonly is introduced by tensioning the tendons.