Compressive strength and thermal conductivity of concrete with nanoclay under Various High-Temperatures

•Nanoclay concrete exhibits increased strength when temperature is not greater than 300 °C.•Nanoclay is benefit to the strength and thermal conductivity coefficient of concrete.•The replacement of cement with 0.3% and 0.5% nanoclay increases the thermal conductivity coefficient of concrete.•Ignition loss can deduce the strength of concrete in high-temperature conditions.

Concrete with nanoclay is utilized to replace cement of 0.1%-0.5% by weight, observing the compressive strength and thermal conductivity coefficients under 25-1000 °C for one hour. Results show that nanoclay concrete exhibits increased strength when temperature is not higher than 300 °C; strength is significantly reduced at a temperature range of 440-580 °C; and strength is lower than 10% of the original strength when temperature reaches 1000 °C. The thermal conductivity coefficient is reduced with increased temperature. When cement is replaced by 0.3% and 0.5% nanoclay, and the compressive strength and thermal conductivity coefficients of concrete increase.