Physicomechanical Properties of Mortar with Diluted EPS as the Binding Material

Abstract

Expanded polystyrene (EPS) is a widely used material in multiple industries, especially in the construction and packaging of appliances and equipment, owing to its properties of lightweight, sound insulation, thermal insulation, and strength. However, in the final stage of the EPS life cycle, multiple environmental issues arise related to the management of this material’s waste due to the large volume occupied and greenhouse gas emissions. This issue has generated growing interest among researchers worldwide, seeking sustainable alternatives to mitigate these negative impacts. In this study, an alternative for utilizing EPS waste was explored, using it in a diluted form with gasoline to manufacture mortar, where EPS acts as a binder. The properties of the material were evaluated, including compressive strength (CS), density (D), and ultrasonic pulse velocity (UPV), using nonparametric statistical tests and multiple linear regression. Variables such as the weight ratio of EPS, the curing method and temperature, and the pressing load were considered in manufacturing 175 cylindrical samples. The results revealed notable strengths of up to 25 MPa, and correlations were established with nondestructive test data, such as UPV. This research opens new perspectives in the search for sustainable solutions for using EPS waste. Optimizing the proportion of diluted EPS using gasoline as a solvent and implementing thermal curing resulted in the material’s outstanding performance. The most imperative results were achieved with a 9% EPS content, followed by 24 h of air drying and an additional 24 h at 110°C. It is relevant to highlight that applying a pressing load of 35 kN led to an additional improvement in compressive strength. The research presents an environmentally friendly curing method characterized by its energy efficiency compared to conventional materials, such as clay blocks. In addition, up to 46% of the solvent evaporates during manufacturing, offering opportunities for solvent recovery techniques. The development of materials, such as dilute EPS mortars, is positioned as a promising and sustainable alternative in construction, with the potential to generate significant savings and environmental benefits. In the construction field, these innovations could find applications in manufacturing masonry blocks, both structural and nonstructural, paving stones, pavements, and filling in structural expansion joints for buildings, among other architectural and structural elements. These applications illustrate the broad spectrum of possibilities of these advanced mortars in the construction landscape.