Anchor Zone Stresses in Prestressed Concrete Beams

A solution for the stress distribuiton in the anchorage zone of post-tensioned concrete beams based on the three-dimensional elasticity theory is presented. The problem is idealized as that of a rectangular prism with normal forces acting on a pair of opposite sides. A three-dimensional solution for this problem is obtained using the Galerkin vector and adopting a multiple Fourier series procedure so that all the governing equations are satisfied. Numerical results were obtained for a particular case and the results compared and analyzed with the results of previous investigations. It was found that the two-dimensional elasticity solution gives good values for the bursting tension except when the end load is concentrated. In this particular case the value for bursting tensile stress given by the present solution is very large compared to the two-dimensional solution. In general, results of actual tests on concrete glock apear to greatly overestimate the bursting stresses.