University of Bradford

The influence of Styrene Butadiene Rubber (SBR) additive on the tensile bond strength of mortar was investigated by testing a series of half brick couplet specimens under axial tension. Eccentric load effects were minimised by using a test arrangement which incorporated a system of universal joints; a standard method of specimen preparation was devised to minimise any variations in workmanship. Three clay brick types, two mortar mixes and three different concentrations of SBR were studied. Increases in the tensile bond strength of about 80% were found with brickwork comprising low suction bricks laid in a 1:3 OPC:sand mortar and an SBR concentration of 16 litres per 50kg of OPC. In alt cases, a reduction in the tensile bond strength was found when using mortar with an SBR concentration of 8 litres per 50kg of cement.