Diagonal Shear Strength of Masonry Wall Using Mortar Joints Mixed with Rubber Tire Crumbs and Fly Ash

Recently, a lot of research has been developed to determine the usefulness of mortar mixed with rubber tire crumbs, which is often called RTC mortar. The advantages of RTC mortar are that it is lighter, more ductile, and has better damping capabilities than ordinary mortar. However, RTC mortar has a weakness, namely its low compressive strength. Several studies have added fly ash to RTC mortar, and it is known to increase the compressive strength of the mortar. This research aims to determine the diagonal shear strength of masonry walls if the mortar joints use RTC mortar with the addition of fly ash. Laboratory testing uses 1⁄2 brick masonry wall test specimens measuring 300x300 mm2 which are composed of clay bricks and mortar joints referring to ASTM E519-02. The research results show that the addition of fly ash to RTC mortar can increase the compressive strength of the mortar, but results in the shear strength of the masonry wall decreasing. To use RTC mortar mixed with fly ash as mortar joints in masonry walls, additional materials need to be considered to increase the bond strength between the mortar and the brick. The effect of adding fly ash to RTC mortar on the bond strength between the mortar and bricks needs to be investigated further.