材料期刊网

通过自然暴露环境条件下掺合料混凝土的早期碳化试验，分析了粉煤灰掺量、矿渣掺量、煤矸石掺量对单掺混凝土碳化深度的影响规律，探讨了双掺掺合料对混凝土碳化深度发展规律的交互作用，并基于试验数据建立了掺合料碳化速度影响系数的表达式。结果表明：单掺粉煤灰掺量小于15%时混凝土的碳化深度略有减小但掺量超过15%后碳化深度随粉煤灰掺量的增加而增加，单掺矿渣混凝土的碳化深度随矿渣掺量的增加而增加，单掺小于20%的煤矸石使混凝土早期抗碳化性能提高但掺入超过30%的煤矸石后混凝土碳化深度明显增加；随着粉煤灰掺量的增加，双掺粉煤灰和矿渣、双掺粉煤灰和煤矸石的混凝土碳化深度增加，在粉煤灰混凝土中掺入25%矿渣或20%煤矸石后混凝土的碳化深度变化较小；在煤矸石混凝土中掺入25%~40%的矿渣时混凝土的碳化深度无明显变化但再掺入超过40%的矿渣时碳化深度明显增大，在矿渣混凝土中掺入20%煤矸石后混凝土的碳化深度增长约40%。

Through the carbonation test of admixture concrete under natural exposure condition, the influence laws of fly ash content, slag content, coal gangue content on the carbonation depth of concrete were analyzed, and the interaction of double-mixed admixtures on the concrete carbonation depth was also discussed. On basis of experimental data, an expression of the influence coefficient of mineral admixture on carbonation speed was established. The results show that the carbonation depth of concrete decreases slightly when the content of single mixing fly ash is less than 15%, and concrete carbonation depth increases with the increase of fly ash content after its content is more than 15%. The carbonation depth of slag powder concrete increases with the increase of slag content. The anti-carbonation performance of concrete increases when the content of single mixing coal gangue is less than 20%, while mixed with more than 30% of coal gangue, the concrete carbonation depth increases significantly. Along with the increase of fly ash content, the carbonation depth of both concrete mixed with fly ash and slag powder and concrete mixed with fly ash and coal gangue increases, concrete carbonation depth changes smaller after in the fly ash concrete adding 25% slag or 20% coal gangue. In the coal gangue concrete adding 25%-40% slag powder, the concrete carbonation depth has no obvious change, while the carbonation depth increases obviously when it mixed with more than 40% of slag powder. In the slag powder concrete adding 20% coal gangue, the concrete carbonation depth will increase by about 40%.