Fracture process in reinforced concrete beams

Crack propagation process in reinforced concrete (RC) beams has been investigated with the aid of acoustic emission (AE) and photoelastic coating methods. Beams with two asymmetric notches were reinforced by a single bar of variable diameter. The ''effective'' crack length was evaluated due to continuous monitoring of isochromatic fringe patterns and spectrum of the AE signal. Some preliminary results concerning fracture toughness parameters of RC beams have been presented.