The Influence of Single Inclusions to the Crack Initiation, Propagation and Compression Strength of Mortar

Previous studies concluded that inclusions highly influence the initial cracking and propagation of the surrounding mortar. This initial cracking and propagation further affects the specimen's compression strength. It was also shown that the ratio of the inclusion area with respect to the mortar and the inclusion configuration determine the stress levels where cracking starts. The stress concentrations were especially pronounced for the inclusions with sharp angles in the line of loading. This paper evaluates the influence of the inclusion-to-mortar area ratio and the inclusion angle to the micro-crack behaviour and compression strength of a single-inclusion mortar specimen. Visual observations to the specimen's behaviours under increasing load were accessed, and the STRAND7 software was utilized to study the stress distributions and concentrations of the mortar area adjacent to the interface between the aggregate and mortar.