Effect of Sand Particle Size (Grading) On Mechanical Strength and Durability of Epoxy Resin Mortar

Abstract

This experimental study compares the properties of traditional cement mortar with epoxy resin-based mortars. In the resin mortars, Portland cement was entirely replaced with a blend of epoxy resin and hardener, used at a fixed ratio of 12.5% resin-hardener mixture to 87.5% aggregates by weight. Various aggregate types and sizes were investigated, including three grades of fine silica sand (fine: 0.063–0.63 mm; medium: 0.16–0.63 mm; coarse: 0.08–1.25 mm) and two grades of marble sand (fine: 1–4 mm; medium: 3–8 mm).

The study evaluates the mechanical performance (compressive and flexural strength), thermal insulation (via thermal conductivity), and durability of these mortars. Durability was assessed through changes in mass and compressive strength before and after exposure to hydrochloric and sulfuric acid solutions.

Results show that mortars made with marble aggregates exhibited slightly lower mechanical strength compared to those with silica sand. However, all epoxy resin mortars demonstrated significantly improved thermal insulation, with thermal conductivity values decreasing from 1.75 to 0.95 W/m·K. Acid resistance was also enhanced in all resin mortars, with the greatest degradation observed in hydrochloric acid and the least in sulfuric acid. Additionally, the reduced water absorption of resin mortars contributed to their improved durability.