预制盾构高性能混凝土的研究和应用

Research and application of prefabricated shield high performance concrete

结合南水北调中线穿黄II-AI、I-B标工程预制盾构管片的施工,对配制管片高性能混凝土的原材料和配合比进行了优选。该配合比通过正交试验,对内掺掺合料的高性能混凝土配合比的多项指标进行了考查,确定出经济合理的配合比。依据该配合比配制的混凝土试验结果表明:混凝土强度达到了C50、拌合物易于浇捣、抗渗等级满足W12、抗冻等级满足F200,碱含量仅2.18 kg/m3;通过蒸养工艺的优化,有效提高了混凝土的早期强度,使8 h(含升、降温过程)蒸养强度达到20 MPa以上,达到每天可以生产两批产品的效率。

Considering the prefabrication shield parts construction of median line of South-to-North Water Diversion Project crossed levels of II-A and II-B on Yellow River, the raw materials and mix ratio of high-performance concrete with tunneling are optimized.The mix ratio is verified by orthogonal experiments, checking various indexes of mix ratio for high-performance concrete with inner admixtures,identifying the economical and appropriate ratio.The results show： the various mixtures are poured and vibrated easily, if the concrete strength reaches C50, and the permeability degree reaches W12, freezing resistance degree reaches F200, the alkali content is only 2.18 kg/m^3;through the steam curing optimization, the early-age strength is enhanced effectively, the curing strength of 8 hours is more than 20 MPa, including the process of raising and lowing temperature, two batch of products can be prepared in one day .