Durability properties of basalt fiber-reinforced mortars with different mineral admixtures exposed to high temperatures

This study investigated the durability properties of mortars containing basalt fiber and various mineral admix-tures against high temperatures. Different types of mortar samples were produced with basalt fiber, metakaolin, silica fume and fly ash. The samples were exposed to temperatures of 400 degrees C, 600 degrees C and 800 degrees C. Residual compressive strength, flexural strength, ultrasonic pulse velocity, mass loss, water absorption, capillary water absorption and microscope analysis tests were carried out. Test results revealed that basalt fiber improved the residual durability properties of the mortars exposed to high temperatures. Basalt fibers exhibited bridging behavior and prevented high temperature-induced cracks. Basalt fibers showed excellent consistency with all three mineral admixtures, and the mineral admixtures increased the contribution of basalt fiber to durability properties. Because of this harmony, basalt fiber-reinforced and mineral admixture-added samples had 86.42% greater residual compressive strength and 144.42% greater flexural strength than the control samples. The void -free internal structure provided by mineral admixtures increased the effect of BF and significantly reduced water absorption, capillary water absorption and mass loss values. UPV tests and microscopic analysis revealed that basalt fiber and mineral admixtures reduced high temperature-induced cracks.