Recycled glass fiber reinforced polymer additions to Portland cement concrete

With recent developments in grinding and sorting technology it is possible to recover glass fibers from waste glass fiber reinforced polymers (GFRPs). The recycled fibers still retain some of the polymer and filler materials, but have the potential to provide some of the same benefits achieved by conventional fiber additions. The research program explored the influence of recycled GFRP on compressive strength, splitting tensile strength, and drying shrinkage in concrete, and alkali silica reaction (ASR) expansion in accelerated mortar beam and concrete prism tests. Compressive strength and drying shrinkage were not improved by recycled GFRP additions at a substitution level of 5 wt% of the coarse aggregate, but splitting tensile strengths were improved in most cases. Negligible expansion was observed from the ASR testing. A scanning electron microscope investigation of the concrete prisms indicated a pozzolanic reaction of the glass fibers.