Experimental Study of Mechanical Properties of Slag Geopolymer Concrete Under High Temperature, Used in Road Pavement

Providing the mechanical properties of concrete used in road paving is of great importance. in the current study, granulated blast furnace slag (gbfs) based geopolymer concrete (gpc) was used with 0-2% polyolefin fibers (pofs) and 0-8% nano silica (ns) to improve its structure. after curing the specimens under dry conditions at a temperature of 60 °c in an oven, they were subjected to tensile strength, modulus of elasticity and ultrasonic pulse velocity (upv) tests to evaluate their mechanical properties. all tests were performed at 90 days of age under ambient temperature (20 ℃) and high temperature (500 ℃). the addition of ns enhanced the whole properties of the gbfs-based gpc. addition of up to 8% ns to the gpc composition at 20% temperature improved the modulus of elasticity test results by 13.42%, tensile strength by 15.19% and upv by 11.58%. addition of up to 2% of pofs to the composition of gpc improved the tensile strength up to 11.76%, modulus of elasticity 07.05% and upv drop up to 12.02%. applying high heat to gpc samples reduced the modulus of elasticity by up to 42%, tensile strength by up to 21% and upv by up to 46%. the effect of heat on the drop in results in control concrete is more than gpc. in the following, by conducting the scanning electron microscope (sem) analysis, a microstructure investigation was carried out on the concrete samples. in addition to their overlapping with each other, the results indicate the gpc superiority over the regular concrete.