Effect of the mixing procedure on the properties of lightweight EPS mortar

Abstract

The management of thermocol wastage has become a major problem in developing countries like Nepal. This paper describes the physical, mechanical, and durability properties of lightweight mortar using expanded polystyrene (EPS) beads, extracted from thermocol wastage, as aggregates. The content of EPS was 0, 20, 30, 40, 50, and 60 percentages by the total volume. The effectiveness of the High Ductile Mortar (HDM) mixing method was compared with the conventional (CON) mixing method on those properties of EPS mortar. The HDM method refers to the addition of EPS in the viscous mortar mixed with the first part of the water and then increasing its workability with the remaining water. The HDM method enhanced compressive strength and Modulus of elasticity by a minimum of 20%, and with a minimum of 10% enhancement in flexural and splitting tensile strengths to the CON method. With the assessment of drying shrinkage, freezing and thawing, and water absorption tests, the durability properties of EPS mortar were found less effective on mixing methods and percentage of EPS. The empirical models were proposed for different strengths and Modulus of elasticity. As result, the structural EPS mortar can be developed with the HDM method up to 30% of EPS but it is limited to 20% with the CON method. Up to 60% of EPS can be used to produce the non-structural mortar with both methods which can replace autoclaved lightweight concrete (ALC) for use in non-load bearing infill and partition walls. EPS beads extracted from thermocol wastage can be re-used to produce structural and non-structural mortar depending on their percentages. It can easily solve the never-decomposing problems of thermocol wastage.