ABSTRACT
In the cross-sectional analyses of Chapters 4, 5 and 6, it was assumed that concrete can carry imposed stresses, both compressive and tensile. However, in reality concrete is not able to carry large tensile stress. If the tensile stress at a point reaches the tensile strength of concrete (Eq. 2.1), cracking occurs. Cracking is irreversible. On a cracked cross-section, tensile stress of any magnitude cannot be carried normal to the crack surface at any time after cracking and tensile forces can only be carried across a crack by steel reinforcement. Therefore, on a cracked cross-section, internal actions can be carried only by the steel reinforcement (and tendons) and the uncracked parts of the concrete section.
