Compressive strength in grouted dry-stack concrete block masonry: Experimental and analytical predictions

Compressive strength is a crucial factor in designing masonry walls to withstand various loading conditions, and it is equally significant for the designing of dry-stack masonry walls. Dry-stack masonry uses interlocking blocks, that enable a faster walling construction than the conventional mortared masonry. Widespread use of this walling system is limited due to lack of detailed design provisions in standards, as opposed to conventional mortared masonry. In this study, the compressive strength properties of un-grouted and grouted dry-stack concrete block masonry were experimentally evaluated. In total, 80 dry-stack concrete block masonry wallettes were built and tested with five different types of dry-stack blocks and three different grouts strength (20 MPa, 32 MPa and 40 MPa). The failure patterns, stress-strain curves and compressive strength characteristics obtained through the testing campaign are reported in this paper. The grouted dry-stack concrete block masonry wallettes demonstrated higher compressive capacities (ranging from 11 % to 152 %) than the corresponding ungrouted concrete block masonry wallettes, the increment was dependent on the grout and block types. The experimental data collected in this campaign was then used to assess the available formulae and tabulated values to predict the compressive strength of dry-stack concrete block masonry wallettes. The predictabilities of these formulae and tabulated values are presented and discussed.