隧道弃渣磨细火山灰对混凝土抗渗性能的影响

本文将中国西南地区某隧道弃渣中的火山岩破碎、粉磨制成磨细火山灰（GVA），分析GVA对混凝土抗氯离子渗透性、吸水特性的影响，基于压汞法（MIP）测试了混凝土孔结构。结果表明，当GVA掺量大于20%（按水泥质量）时，混凝土电通量和单位面积吸水量显著增加；建议GVA掺量不超过20%，复掺3%~5%的硅灰（SF）可降低混凝土中50~100nm有害孔含量，进而提升GVA混凝土的抗渗性能。

Influence of ground volcanic ash produced by tunnel waste slags on impermeability of concrete

In this study, the volcanic rock in the waste slags of a tunnel in Southwest China is crushed and ground into ash. The influence of the ground volcanic ash (GVA) on the chloride ion permeability and water absorption characteristics of concrete is analyzed. The pore structure of concrete is tested based on mercury injection method (MIP). The results show that when the content of GVA is more than 20% (by mass of cement), the electric flux and water absorption of concrete increase significantly. It is suggested that the content of GVA should not exceed 20%, and adding 3%~5% silica fume (SF) can reduce the content of 50~100nm harmful pores in concrete, so as to improve the impermeability of GVA concrete.