Polymer-modified mortar flexibility of the masonry-concrete structure interface

Abstract

High crack occurrences at the masonry-infilled wall partition-reinforced concrete structure interface is a problem that challenges the Brazilian construction process. Improving the mortar’s flexibility is suggested as a potential solution, but it's still not widely known. This paper evaluates industrialized mortar properties modified with four polymers and one plasticizer additive. The research methodology consisted of an experimental investigation related to the mortar properties using styrene-acrylic copolymer (SAE), polyvinyl acetate copolymer (PVAc), styrene-butadiene copolymer (SBR), white glue PVA (polyvinyl acetate), and a sulfated ethoxylated fatty alcohol salt plasticizer additive. The polymers were used in addition to (4%, 5% and 8%) and instead of (4% and 5%) the amount of water established by the manufacturer of the reference mortar, while the amount of additive used was 0.08%. The investigation characterization considered the fresh and hardened conditions, especially, the flexibility evaluation, and tests of elasticity modulus and transverse deformation were carried out, in addition to scanning electron microscopy (SEM). The results showed that there was an elasticity modulus reduction of all mixtures compared with the reference mortar without modification. The transverse deformation results range from a minimum of 0.23 mm (SBR) to a maximum of 0.94 mm (SAE). Regarding SEM, the tests with polymers have smoother and less porous surfaces. The mortar flexibility performance with different additive contents is the main contribution of this research.