隧道弃渣磨细火山灰对水泥水化及混凝土抗压强度的影响

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），通过扫描电镜（SEM）、X射线衍射（XRD）测试该火山灰的物理和化学性能，分析GVA对普通硅酸盐水泥水化、混凝土抗压强度及碳排放的影响。结果表明，GVA会延缓水泥水化进程，但延缓作用弱于同掺量粉煤灰（FA）；GVA替代水泥50%（质量）时，混凝土28d抗压强度下降38.8%，掺入3%~5%硅灰（SF）可明显提高混凝土抗压强度；GVA替代水泥降低了混凝土碳排放指数（CI），建议掺量为20%。

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

In this study, the volcanic rock in the waste slags of a tunnel in Southwest China is crushed and ground into ash. The physical and chemical properties of the ground pozzolanic ash are tested by SEM, XRD and so on, and the effects of ground volcanic ash (GVA) on the hydration of ordinary Portland cement, compressive strength of concrete and carbon emission index are analyzed. The results show that GVA can delay the hydration process of cement, but the delaying effect is weaker than that of the same amount of fly ash (FA). When GVA replaces 50% (by mass) content of cement, the 28-day compressive strength of concrete decreases by 38.8%, while adding 3%~5% silica fume (SF) can significantly improve the compressive strength of concrete. GVA replacing part of cement reduces the carbon emission index (CI) of concrete, and the recommended dosage is 20%.