Bond strength evaluation of polymer modified cement mortar incorporated with polypropylene fibers

Bond strength is the adhesion between an overlay and a substrate mortar; it is the key parameter ensuring durability and having a monolithic system. A proper bond is essential to resist any stresses associated with volume changes, freeze-thaw cycles, and vibrations at the interface. Polymer-modified cement mortar (PCM) is one of the most well-known adhesive materials, used widely as a binding agent in engineering construction. Two forms of PCM were investigated in this study. These products are known commercially as Sika MonoTop (R)- 620, a form of repair material for concrete structures, and DCP Cemfix 2CS, which is occasionally used as an adhesive to connect the tiles to the concrete base. The effect of polypropylene fiber with volume fractions of 0, 0.5, 0.75, and 1 % was investigated using three different water-to-binder ratios. A total of 24 distinct mixes were made. The material's compressive strength, flexural strength, and bond strength were all determined. The bond strength of each mix was assessed using the Slant-Shear and Pull-off test methods. The bond strength values derived by Slant-Shear and Pull-off tests had a high correlation, about 85 %. Furthermore, bond strength was connected with the material's compressive and flexural strength with 95 % and 86 % with Slant-Shear, and 80 % and 76 % with Pull-off, respectively.