地铁盾构管片混凝土电通量性能的试验研究

Experimental research on electric flux performance of concrete for metro shield segment

为了提高混凝土抗氯离子渗透性能,延长地铁盾构管片的服役寿命,研究了养护龄期、掺合料种类及掺量对混凝土电通量的影响规律。试验结果表明,在56 d前,混凝土电通量随着养护龄期的延长而降低;低活性的粉煤灰会增大混凝土的电通量,降低混凝土抗氯离子渗透性能;矿粉与硅灰的掺入都可有效降低混凝土的电通量,混凝土电通量与矿粉的掺量具有良好的线性关系;硅灰的加入对降低混凝土电通量的效果非常显著,掺量为7.5%时,混凝土的电通量达到最低值,电通量下降90.2%。同时,结果对于普通混凝土的高性能化也具有一定指导意义。

In order to improve the resistance to chloride ion penetration of concrete, extend the service life of the metro tunnel seg- ments, we studied the influence of curing age, type and dosage of mineral admixture on concrete electric flux. The test results show that 56 days ago, the concrete electric flux decreases with extended curing ages. dding fly ash with low activity to increases the concrete e- lectric flux, reducing the concrete resistance to chloride ion permeability. Addition of slag and silica fume can effectively reduce the con- crete electric flux, and the concrete electric flux has a good linear relationship with slag content. Addition of silica fume can effectively reduce the concrete electric flux, when the content is 7.5% the concrete electric flux reaches a minimum value,the electric flux decrea- sing by 90.2%. Meanwhile, the results of this study also has some significance for the improvement of ordinary concrete.