关键词: 混凝土;粉煤灰掺量;沙漠砂替代率;碳化性能

Abstract: The carbonation resistance tests of concrete with single fly ash,single desert sand and compound of fly ash and desert sand at 3 d,7 d,14 d,28 d and 56 d were carried out. The influences of fly ash dosage and desert sand replacement ratio on the carbonation resistance property of concrete were analyzed. The regression model among the carbonation depth of concrete at 28 d and fly ash dosage and desert sand replacement ratio was established. Experimental results show that the carbonation depth of concrete increases with fly ash dosage. The carbonation depth of concrete with single fly ash at early age increases faster than the latter. With the enhancement of desert sand replacement ratio,the carbonation depth of concrete with single desert sand decreases firstly,and then increases. When desert sand replacement ratio is equal to 20%,the carbonation depth of concrete with single desert sand reaches minimum value. When fly ash and desert sand are mixed into concrete simultaneously,the carbonation depth of concrete with the compound of fly ash and desert sand reaches the minimum value on the condition that the fly ash dosage is 10% and desert sand replacement ratio is 20%.

Key words: concrete;fly ash dosage;desert sand replacement ratio;carbonation property