Effect of VAE emulsion and inorganic fillers on the properties of styrene-acrylic emulsion based cement composite joint sealant

Abstract

A VAE emulsion was used to replace part of styrene-acrylic emulsion, and different inorganic fillers were used alone or compounded to prepare styrene-acrylic emulsion based cement composite joint sealant (SCJS). Leveling test, pour consistency test, constant elongation test, tensile test and shear test were conducted for the SCJS. The effect of VAE emulsion dosage and different inorganic fillers on the properties of SCJS were studied through measuring the working capabilities (leveling property and pour consistency), cohesive properties (form at the fixed tensile displacement and elastic recovery rate), tensile properties (tensile strength property, tensile deformation property, tensile energy consumption performance, and tensile failure mode) and shear properties (shear strength property, shear deformation property, shear energy consumption performance, and shear failure mode) of the SCJS. The effect of VAE emulsion and inorganic fillers on SCJS pore structure was also analyzed by a MIP test. The results showed that VAE emulsion and inorganic fillers did not affect working capabilities of SCJS. With the content of VAE emulsion increased, both tensile strength and shear strength of SCJS decreased, while in general, the deformation and energy consumption indexes increased significantly, with good cohesive properties, and both tensile and shear failure modes were of cohesiveness failure. The pore volume, pore size and large pore ratio decreased significantly. When talcum powder and heavy calciumcarbonate were used alone or compounded in a 1:1 ratio as inorganic fillers, SCJS had good cohesive properties and deformation flexibility, the tensile and shear failure modes were of cohesive failure. When the talcum powder and heavy calcium carbonate were compounded as inorganic fillers, the pore volume, pore size and large pores of SCJS decreased significantly. The optimal VAE emulsion dosage ranged from 30% to 40%, and for the inorganic fillers of SCJS, 50% talcum powder + 50% heavy calciumcarbonate compound was appropriate.