Experimental Investigation of Mechanical Property Improvement of Expanded Polystyrene Concrete with Glass Fibers

The application of expanded polystyrene (EPS) concrete in the construction industry is significantly increasing due to its many advantages, including low cost, fast construction speed, light weight, high temperature resistance, and environmental protection. However, the issue of low strength has not yet been resolved. In this study, glass fiber powder was adsorbed on the surface of EPS with epoxy resin curing agent as binder, thus forming a new type of lightweight aggregate of glass fiber–reinforced EPS. Four kinds of chopped glass fiber with different lengths and three kinds of chopped fiber with different contents were selected to be mixed into the matrix of EPS concrete. The interface between glass fiber and matrix was observed using a scanning electron microscope (SEM). It was found that the glass fiber was evenly dispersed in the cement matrix. This uniform dispersion has been proven to improve the overall crack resistance and toughness of concrete. The bonding interface between the EPS ball outer glass fiber powder and cement is tight and seamless, which reduces the brittle failure of concrete caused by excessive internal voids. The experimental results demonstrate that in several groups of designs in this experiment, the gain effect of using 12-mm glass fiber with a mass fraction of 1.5% is better. At this time, the compressive strength of the concrete sample is 9.32 MPa, 39.3% higher than that of the sample without fiber, and the density is 1.189 g/cm3, only 7.6% higher. In view of the good cost-benefit ratio, economic benefit, and simple implementation mode of glass fiber, the experimental results can provide a valuable reference point for improving the strength of lightweight concrete.