Postcracking Behavior of Prestressed Masonry in Flexure

To fully exploit the structural potential of prestressed masonry in flexure, it is essential to know its postcracking behavior. For this, a nonlinear finite element model has been developed to predict the complete response of prestressed masonry structural elements subjected to a monotonically increasing load. The present model incorporates the effects of geometric as well as material nonlinearity caused by nonlinear stress-strain relationship, cracking and crushing of masonry, yielding of prestressing steel, and predicts deflections, stresses and strains at different points in masonry and in steel. The model is suitable for predicting behavior of both bonded and unbonded in-plane prestressed masonry structures. The masonry super element has been employed to make such an analysis economically viable for prediction of the behavior at macro level. For the purpose of validation of the proposed model, the experimental test results of prestressed masonry beams and slab specimens have been used. The theoretically predicted results using the proposed model and the reported test results are found to be in good agreement both in pre- and postcracking regimes.