Residue compressive strength, ultrasonic pulse velocity and mass loss of nano sio2 mortar after exposure to elevated temperatures

In this study, the effect of elevated temperatures on chemical composition and mechanicalproperties of mortars with nano silica was investigated. Mortars with 0.5, 1, 1.5 and2% nano silica as cement replacement were prepared and then exposed to 200 °C, 400°C, 600 °C, 800 °C and 1000 °C. Residual compressive strength, mass loss andultrasonic pulse velocity of samples were also obtained. Along with the loss ofresidual compressive strength, the ultrasonic pulse velocity of mortar was also reducedat elevated temperature. It was found that after an initial increase in compressivestrength at 200 °C for the mortar specimens, the strength decreased considerably athigher temperatures. Moreover, 1% replacement of NS showed higher strength for alltemperatures.

Keywords:

elevated temperatures , mortar , nano silica , Residual compressive strength , mass loss , ultrasonic pulse velocity