ACOUSTIC EMISSION MONITORING OF STEEL-FIBER REINFORCED CONCRETE BEAMS UNDER BENDING

The present paper describes acoustic emission (AE) behavior of concrete under four-point bending. Different contents of steel fiber were included to investigate their influence on the loadbearing capacity, as well as on the fracture mechanisms. The main crack was accompanied by many minor cracks indicating that the fibers increased the width of the fracture process zone. The total AE activity was directly proportional to the fiber content. The subsequent study of the AE waveform characteristics revealed that the increase in the fiber content resulted in a shift from the tensile to the shear mode of failure due to improvement of the weak tensile properties of concrete.