The effects of high temperature and cooling regimes on the mechanical and durability properties of basalt fiber reinforced mortars with silica fume

Abstract

This study implemented an experimental program to evaluate performance of high strength mortars with basalt fibers (BF) and silica fume (SF) at ambient and elevated temperatures. The effects of ambient and elevated temperatures and curing regimes on the physical, mechanical and durability properties of BF reinforced SF blended mortars were investigated in this study. The effects of two types of cooling namely air cooling and water cooling after exposed elevated temperatures on the durability and mechanical performance of mortars was also assessed. In this study, all mortar mixtures were modified by replacing ordinary Portland cement (OPC) by 10% SF by weight and mortar mixtures were fabricated by the inclusion of BF at the rates of 0, 0.2, 0.4 and 0.6% by volume. The specimens were examined for compressive strength, flexural strength, porosity, ultrasonic pulse velocity, water absorption and unit weight and Scanning Electron Microscopy (SEM) analysis at ambient and elevated temperatures under air and water cooling after exposure to elevated temperatures. The effects of using different BF contents on the flowability of mortar mixtures were assessed by slump test. The results indicated that the flowability of mortar mixtures reduces with increasing fiber content. Test results also showed that with the inclusion of BF, the compressive strength enhances significantly and basalt fibers dosages of 0.2, 0.4, and 0.6% increased the compressive strength of mortar specimens by 19.46%, 21.77% and 31.40%, respectively, compared with that of reference mixture M1 at ambient temperature.