Influence of glass wool fiber reinforcement and heat resistant coating on behavior of self-compacting mortar at elevated temperatures

Abstract

In present study, the influence of glass wool fiber (GWF) reinforcements and the application of heat resistant paint has been studied on the performance of self-compacting mortar (SCM) at ambient condition and at elevated temperatures of 200 °C, 400 °C, 600 °C, and 800 °C. Sixteen mix designs were prepared for SCM (with 25% fly ash) using GWF reinforcement of 0%, 0.5%, 1%, 1.5%, and varying the effective water to cement (w/c) ratio as; 0.43, 0.49, 0.55, and 0.70. The intrusion of GWF resulted into decrease in slump flow and v-funnel flow speed, increase in yield stress and plastic viscosity, whereas, the influence of effective w/c ratio on rheology of fresh SCM mix was opposite to glass wool fiber (GWF). For all variation of effective w/c ratio and GWF reinforcements, the values of slump flow and v-funnel flow were within the EFNARC limits. Increasing GWF reinforcement and the effective w/c ratio, compressive strength of SCM were decreased, but GWF yielded positive impact on flexural strength. SCM with 1% GWF reinforcements showed best result at effective w/c of 0.43, imparting highest flexural strength of 8.7 MPa. The application of heat resistant coating has shown a significant protection to SCM samples up to the maximum heating temperature of 800 °C by limiting the loss of mechanical strength within small percentage, whereas, the loss of mechanical strength was severe (about 45% to 65%) for uncoated samples. Thermogravimetric (TG) analysis of SCM powder revealed the thermal stability of SCM mix up to 1000 °C and the mass loss occurred correspond to the heating at temperature of 400 °C and 800 °C was 0.3%, and 7.5%, respectively.