A discussion on major factors affecting crack path of concrete-to-concrete interfacial surfaces

This paper elaborates major factors affecting the crack path of concrete-to-concrete interfacial surfaces produced with placing joint. Eleven types of specimens were employed for the evaluation of tension softening diagram followed by surface observation of the ligament after fracture test. The surface analysis revealed that the layer of Ca(OH)2 plays a primary role on the crack path. The authors discuss the relationship between fracture mechanics parameters and the ratio of fractured part which excludes detached part in the ligament. The mechanism for determining crack path near concrete-to-concrete interface is proposed using ‘scattered hole model’.