An experimental study on the in-plane behavior of interlocking blocks with different interconnection mechanisms

The utilization of interlocking systems in masonry structures provides numerous advantages, such as decreased construction time, improved construction quality, and enhanced structural integrity. Despite these advantages, the behavior of interlocking blocks is still not fully understood due to the variations in the construction methods and the geometry of these blocks around the world. Considering the limited capacity, as well as the inherent brittle behavior of walls built with interlocking blocks under extreme loads, it is crucial to employ supplementary techniques that enhance structural behavior and increase ductility through various connecting mechanisms. This experimental study aims to investigate the effectiveness of adhesive paste as an alternative to mortar, and its combination with grout and steel rebar to improve the structural performance of these walls. The proposed interlocking system is designed with middle and side holes to facilitate incorporating the connecting elements. For this purpose, compression, diagonal shear, and in-plane shear behaviors of specimens made up of blocks interconnected with adhesive paste, grout and steel rebar were tested and the results including failure mode, strength, and force–displacement response were discussed. Under compressive loading, the use of adhesive paste between the blocks effectively increased the strength of the masonry prism. In the diagonal and direct shear tests, where the interlocking keys are directly engaged, the presence of paste and grout was found to have a positive influence on the capacity. The incorporation of grout, steel rebar, and adhesive paste substantially improved the ductility as well as the strength in different loading conditions.