Investigation of Shale Brick Interface with Cement‐Lime and Polymer‐Modified Mortars

Abstract

Bonds between cement‐lime mortar and shale brick, and between polymer‐modified mortar and shale brick, were studied using a scanning electron microscope (SEM). The results showed that the bond is greatly influenced by the microstructure and chemical composition of the mortar at the interface contact area and by the microstructure of the brick surfaces. For relatively porous bricks, cement‐lime mortars give a better bond, apparently due to better interpenetration of the fresh mortar into the open pores of the brick, creating a greater bond area. The presence of calcium contributes to good bonds, while large amounts of silicon were found in poorly bonded areas. Latex‐modified mortars are not able to penetrate brick surfaces and are able to create strong bonds only on limited locations and allow water to enter brick masonary.