Analytical and Experimental Studies on Interface between Different Mortars and Brick

Abstract

Usage of masonry materials in a country like Iran is still significantly high. As most of the failures during an earthquake in this system is failure caused by low ductility of cement mortars and also the high rate of carbon dioxide produced by cement. Experiences of Kermanshah earthquake in 2017 in Iran has doubled the importance of this issue. Hence, in the present investigation, an attempt to enhance the shear bond characteristics of structures constructed by masonry using green materials has been made. “Taftan” natural Pozzolan and two types of rice husk ash (RHA) was used in mix design of used mortars as a green material. In this investigation, a direct shear test (DST) device is modified and proposed to determine brick-mortar shear bond strength. The proposed method of applying DST has the advantageous of changing normal load and determine pure bond characteristics. For this purpose, two bricks bonded to each other by a mortar and subjected to the shear load. Tests were performed using DST for nine different types of mortars with different normal loads. The effect of increasing shear bond strength over time was also studied. Tests showed that using waste material like RHA in mortar is reasonable as its causes to the increase mortar plasticity and failure strain and also reduce the cost of mortar and its environmental effect.