Experimental study of the cracking behavior of specimens containing inclusions (under uniaxial compression)

This paper presents the results of an experimental investigation on the cracking behavior of brittle heterogeneous materials. Unconfined, uniaxial compression tests were conducted on prismatic gypsum specimens containing either one, or two, inclusions. These inclusions were of different strengths, stiffnesses shapes, and sizes. Emphasis was placed on crack coalescence processes associated with specimens containing an inclusion pair, as this was the primary objective of the research. Some observations reported in this study compare well with those of other researchers as the overall cracking sequences are similar. On the other hand, the amount of debonding observed in this study at the inclusion interface is significantly less than what was previously observed. Moreover, the extent of shear crack growth at an inclusion boundary increased substantially in specimens containing two inclusions, compared to those with single inclusions.