Polystyrene-modified mortar

This paper presents the results of a study on the addition of sulfonated polystyrene, derived from discarded plastic cups, as an additive in mortars. Mortars with polystyrene contents of 0.0, 0.2, 0.6, 1.0 and 1.4% relative to the cement mass were analysed. Portland CPV - ARI cement and washed sand were used in a 1:4 mass ratio. To evaluate the influence of the addition of polystyrene on the properties of the mortars, the consistency index, water retention and absorption, void ratio, static modulus of elasticity, compressive strength, flexural strength and potential tensile bond strength were determined. Compared to mortar without additives, the modified mortar showed an increase in tensile adhesion strength, flexural tensile strength, porosity, consistency, water absorption and retention. However, the increase in the content of sulfonated polystyrene leads to a reduction in the modulus of elasticity, specific mass and water absorption by capillarity, which may indicate that the increase in the number of pores in the mortar do not intercommunicate and that the polymer film contributes to the improvement of the mechanical properties.