碳化与酸雨侵蚀共同作用下钢纤维混凝土的耐久性能

Durability of Steel Fiber Reinforced Concrete under the Combined Effects of Carbonization and Acid Rain Erosion

测试了碳化和酸雨侵蚀共同作用下钢纤维混凝土的质量变化率、劈拉强度变化率、溶蚀深度、中性化深度,系统研究了碳化和酸雨侵蚀共同作用下钢纤维混凝土的耐久性能.结果表明:碳化加速了酸雨侵蚀下混凝土的溶蚀;碳化和酸雨侵蚀共同作用下的混凝土质量损失率、劈拉强度损失率以及溶蚀深度都大于单独酸雨侵蚀作用下的混凝土质量损失率、劈拉强度损失率以及溶蚀深度,中性化深度大于单独酸雨侵蚀下中性化深度和单独碳化作用下中性化深度的叠加;碳化与酸雨侵蚀作用对混凝土中性化都有贡献,并且贡献大小几乎相当.适量钢纤维的掺入能有效抑制酸雨侵蚀引起的混凝土溶蚀,并降低混凝土中性化速度;掺1.5%(体积分数)钢纤维混凝土的耐久性能最优.

The durability of steel fiber reinforced concrete（SFRC） was investigated under the combined effects of carbonization and acid rain erosion by testing mass change rate, splitting tensile strength change rate, corroded depth and neutralization depth. Test results indicate that the concrete corrosion under the acid rain erosion effect is accelerated by carbonization. Under the combined effects of carbonization and acid rain erosion, the concrete mass loss rate, splitting tensile strength loss rate and corroded depth are greater than those of concrete under the acid rain erosion effect alone, and the neutralization depth is larger than the superposition of that under the acid rain erosion effect and that under the carbonization effect. The effect of carbonization and acid rain erosion has almost equal contribution to the neutralization of concrete. Proper mixture of steel fiber can effectively inhibit the concrete corrosion under the acid rain erosion effect and reduce the neutralization speed. The concrete with 1.5 % （by volume） steel fiber is of the optimal durability.