粉煤灰及沙漠砂对混凝土抗碳化性能的影响

通过进行单掺粉煤灰、单掺沙漠砂、双掺粉煤灰和沙漠砂混凝土3d、7d、14d、28d和56d抗碳化性能试验,分析了粉煤灰掺量和沙漠砂替代率对混凝土抗碳化性能的影响,建立了混凝土28 d碳化深度与粉煤灰掺量及沙漠砂替代率之间回归关系模型.试验结果表明:对于单掺粉煤灰混凝土,随着粉煤灰掺量增加,混凝土碳化深度逐渐增大,且碳化早期比后期增长较快;对于单掺沙漠砂混凝土,随着沙漠砂替代率增加,混凝土碳化深度呈先减小后增大趋势,沙漠砂替代率20%时混凝土碳化深度最小;对于双掺粉煤灰和沙漠砂混凝土,粉煤灰掺量10%,沙漠砂替代率20%时混凝土碳化深度最小.

Influence of Fly Ash and Desert Sand on the Carbonation Resistance Property of Concrete

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%.