Tensile bond strength of polymer modified mortar

This paper describes an investigation of improving the bond strength of mas onry mortars through the use of polymer additives, so that more efficient u se of unreinforced masonry may be realized. A brief description of the mech anisms involved in polymer-modification of cementitious materials is provid ed as back-ground for the experimental program. Results from a clay brick, type S cement-lime masonry mortar bond strength testing program investigati ng various admixtures are presented. The admixture treatments include numer ous latexes, a defoaming agent, and a superplasticizer. Test specimens were cured under both moist and dry conditions. Very significant increases in b ond strength were realized through the addition of several polymers, a plas ticizer, and combinations of polymers and the plasticizer.