Na^+和SO_4^(2-)对混凝土Cl-扩散系数的影响

Effect of Na^+ and SO_4^(2-) to the concrete chloride-ion-diffusion-coefficient

采用Cl-扩散系数法测试混凝土试件不同龄期的Cl-扩散系数以及经过冻融循环后的Cl-扩散系数变化情况。研究不同掺量的Na+和SO42-对混凝土内部结构和抗冻性能存在的影响以及影响程度,以保证混凝土的耐久性。表明随着Na+量增加,混凝土的Cl-扩散系数提高,冻融循环后混凝土Cl-扩散系数差值降低;随着SO42-量增加,混凝土的Cl-扩散系数降低,冻融循环后混凝土Cl-扩散系数差值提高。Na+对混凝土抗渗性不利,对混凝土抗冻性有利;SO42-对混凝土抗渗性有利,对混凝土抗冻性不利。

Study the effect and effect degrees of different quantity Na＋ and SO42- to the concrete internal structure and anti-freezing,to guarantee the durability of concrete.The chloride-ion-diffusion-coefficient method is used to test the concrete chloride-ion-diffusion-coefficient in different hydrat- ed periods and the change of chloride-ion-diffusion-coefficient after the freezing and thawy circulation.And along with the Na＋ quantity increase,the concrete chloride-ion-diffusion-coefficient is raised,the margin of chloride-ion-diffusion-coefficient after the freezing and thawy circulation is de- creased;Along with the SO42- quantity increase,the concrete chloride-ion-diffusion-coefficient is decreased,the margin of chloride-ion-diffusion-co- efficient after the freezing and thawy circulation is raised.So the Na＋ is disadvantageous to the concrete anti-infiltration,but advantageous to the con- crete anti-freezing;And the SO42- is advantageous to the concrete anti-infiltration,but disadvantageous to the concrete anti-freezing.