掺偏高岭土免蒸养衬砌管片混凝土的配制技术

摘要

According to later strength and durability of the precast concrete segment affected by steam curing process and mix proportion of pure portland cement,the preparation of non-steam curing segment by compound mixture of metakaolin and fly ash was proposed.The results show that the early strength of concrete is improved significantly by mixing with the metakaolin,the strength of segment demoulding and non-steam curing is achieved under natural curing condition,the impermeability,dry shrinkage property and carbonation resistance of concrete could be improved by mixing with metakaolin,the compound mixture of metakaolin and moderate fly ash can make up for the lack of concrete crack resistance with single metakaolin mixing.%针对蒸汽养护工艺和纯硅酸盐水泥配合比易影响预制混凝土管片的后期强度和耐久性问题,提出采用偏高岭土与粉煤灰复掺配制免蒸养管片.试验结果表明:掺入偏高岭土可显著提高混凝土早期强度,在自然养护条件下达到管片脱模强度要求,实现免蒸养;掺入偏高岭土可改善混凝土的抗渗性能、干缩性能和抗碳化性能;偏高岭土与适量的粉煤灰复掺可弥补单掺偏高岭土抗裂性能不足.