EFFECTS OF DESERT SAND REPLACEMENT RATE AND FLY ASH CONTENT ON THE COMPRESSIVE STRENGTH OF CONCRETE UNDER LOW TEMPERATURE

In order to study the effects of desert sand replacement rate and fly ash content on the compressive strength of concrete under low temperature, the compressive strength tests of concrete with desert sand, fly ash, the mixture of desert sand and fly ash under room temperature, -10℃, -20℃, -30℃ were carried out. The influences of temperature, desert sand replacement rate and fly ash content on the compressive strength of concrete were analyzed. The regression model between the compressive strength of concrete with temperature, desert sand replacement rate and fly ash content was established. The test results showed that the compressive strength of concrete increased under low temperature with the decrease of temperature. Whereas, after being subjected to low temperature, the compressive strength of concrete decreased with the decrease of temperature. For the concrete with desert sand, the compressive strength of concrete increased firstly, and then decreased with the increase of desert sand replacement rate. The compressive strength of concrete with desert sand replacement rate 50% was the maximum value. For the concrete with fly ash, the compressive strength of concrete tended to decrease with the increase of fly ash content. For the concrete with the mixture of desert sand and fly ash, the compressive strength of concrete reached the maximum value when desert sand replacement rate and fly ash content were 50% and 10%, respectively.