Non-linear behavior of weak brick-strong mortar masonry in compression

Abstract

Non-linear (stress-strain) properties of masonry form a pre-requisite in carrying out the non-linear analysis of structures. A detailed study on the non-linear behavior of strong burnt clay brick masonry was carried out by Kaushik et al. (J Mater Civ Eng 19:728-739, 2007), whereas non-linear stress-strain characteristics for weak brick-strong mortar was not available. To evaluate the same, fly ash bricks whose compressive strength was lesser than the strength of mortar were selected. Prisms with three different grades of mortar: Strong (cement:sand 1:3), intermediate (1:4) and weak (1:6) were constructed to evaluate the non-linear behavior of weak brick-strong mortar, and to assess the influence of strength of mortar on masonry prisms. Specimens were instrumented with strain measuring instruments and tested under monotonic compressive loading using servo controlled hydraulic actuator. Stress-strain curves for weak brick-strong mortar masonry were plotted and the results were compared with strong brick-weak mortar masonry (Kaushik et al. J Mater Civ Eng 19:728-739, 2007). From the results, it was observed that strength of weak brickstrong mortar masonry was lower when compared to strong brick-weak mortar masonry, but the failure strain observed in case of weak brick-strong mortar masonry was significantly higher when compared to strong brick-weak mortar masonry.