硫酸盐腐蚀对透水混凝土抗压强度及透水性能的影响

Effect of sulfate corrosion on compressive strength and permeable properties of pervious concrete

采用体积法配制了3种不同透水混凝土,对其不同硫酸盐腐蚀龄期(30、60、90、120 d)的抗压性能及透水性能进行研究,分析了硫酸盐对透水混凝土的腐蚀机理。结果表明:随硫酸盐腐蚀龄期的延长,透水混凝土的抗压强度有不同程度的降低;腐蚀龄期一定时,骨料粒径越小,其抗压强度的降幅越大。透水系数随腐蚀龄期的延长有增大的趋势,腐蚀龄期一定时,骨料粒径越小,其透水系数的提升幅度越大。硫酸盐与混凝土内部集料反应,生成物体积发生膨胀而导致混凝土内部开裂,使混凝土整体强度降低;并导致混凝土的胶凝物质含量下降,由于生成物自身强度较低,使混凝土的粘结力随之下降,宏观强度降低。

Three types of different pervious concrete were prepared by volume method. The compressive properties and permeable properties of pervious concrete in different sulphate corrosion ages(30,60,90,120 d) were tested. The corrosion mechanism of sulfate to pervious concrete was analyzed. The results show that the compressive strength of pervious concrete decreases with the increase of sulfate corrosion age. When the corrosion age is fixed,the smaller the aggregate size,the greater the decrease range of compressive strength. The permeability coefficient increases with the increase of corrosion age. When the corrosion age is fixed,the smaller the aggregate size is,the greater the increase range of permeability coefficient. The reaction of sulphate and components-aggregate causes the volume dilation of the concrete,which resulting in cracking inside the concrete,and then resulting in a decrease in the overall strength of the concrete. On the other hand,the content of cementitious material in concrete is decreased,and the strength of the product itself is low,which leads to the decrease of the bond strength of concrete and the decrease of the macro strength.