Extent of healing of cracked normal strength concrete

The goal of the research presented here is to investigate the extent of hea ling of cracked concrete. A feedback-controlled test was used to generate a crack with a controlled width in concrete specimens. Then, water permeabil ity was evaluated by a low-pressure water permeability test (WPT). Elastic wave signal transmission measurements were performed immediately after crac king and repeated after 100 days of WPT. Immediately after cracking, water permeability increased and the signal transmission decreased with increasin g initial crack width. The water permeability of cracked specimens decrease d significantly, whereas the signal transmission increased with time. Both permeability and transmission measurements suggest autogenous healing of th e cracks. However, the recovery in signal transmission with crack healing i s not as spectacular as changes in permeability, inferring only partial mec hanical healing of the cracks.