Mechanism of fatigue crack growth in concrete

Abstract

Through recent studies on the fracture mechanics of concrete, the existence of a fracture process zone has been indentified, and governing mechanisms are clarified. Although analytical prediction of crack growth phenomena under static, mode I loading has been made possible, the mechanism of fatigue crack growth under cyclic loading has not been studied. In the present study an analytical model of fatigue crack growth in concrete is proposed in order to identify its governing mechanism. Consideration is based on the tension-softening behaviour of concrete under cyclic load. Low-cycle fatigue crack growth tests have been carried out in which the distribution of crack opening displacement was measured by the laser speckle method. Experimental results are compared with analytical predictions by the proposed model in order to discuss the mechanism of fatigue crack growth.