Mechanical and thermal properties of insulated mortar incorporated with GFRP powder

The negative impact of glass fibre-reinforced polymers (GFRP), slag and fly ash on the environment has garnered significant attention; therefore, the aim of this study was to explore the possibility of replacing cementitious materials with GFRP powder, slag and fly ash to develop mortar with better thermal insulation and mechanical properties. The use of GFRP powder to replace cementitious materials was investigated. The experimental variables were the substrate, fly ash, and GFRP powder content. To analyse the mortar materials and specimens, various tests including X-ray fluorescence, X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and mechanical and thermal property testing were performed. The mortar with 20% GFRP powder using the ordinary Portland cement or alkali-activated slag as cementitious material exhibited excellent mechanical and thermal properties at 0.6 water-cement ratio. The use of fly ash as a substitute for cement resulted in a decrease in flexural strength by approximately 50%, compressive strength by 30%, and thermal conductivity by 66.3%. The use of fly ash and GFRP powder instead of cement reduced thermal conductivity of the mortar but decreased its flexural and compressive strengths by up to 40%.