聚羧酸高效减水剂对混凝土抗碳化性能的影响

Effect of Polycarboxylate Superplasticizer on Carbonation Performance of Concrete

为研究聚羧酸高效减水剂对混凝土抗碳化性能的影响,试验采用不同水胶比、减水剂掺量的混凝土试件,在相对湿度分别为75%、54%的条件下碳化28d,测定碳化试件不同深度处碳化产物CaCO_3的含量,并绘制碳化产物CaCO_3含量和深度的曲线。试验结果表明:当水胶比小于或等于0.45,聚羧酸高效减水剂的掺入对低水胶比混凝土的碳化作用不明显;水胶比为0.50时,较低掺量减水剂对混凝土的碳化作用不显著,但掺量较高时(0.8%),对混凝土的碳化性能不利。

In order to study the effect of polycarboxylate superplasticizer on the carbonation resistance of concrete, the concrete specimens with different water-to-binder ratio and different water reducing agent dosage have been tested and carbonized under the conditions of relative humidity of 75% and 54% respectively. 28 d, the content of carbonized product CaCO3 at different depths of the carbonized test piece has been measured, and the CaCO3 content and depth curve of the carbonized product have been plotted. The test results have shown that when the water-binder ratio is less than or equal to 0.45, the incorporation of polycarboxylate superplasticizer has little effect on the carbonation of concrete with low water-binder ratio;when the water-binder ratio is 0.50, the amount of water-reducing additive on concrete is low. The carbonization effect is not significant, but when the amount is high(0.8%), the carbonation resistance of the concrete would be unfavorable.