免蒸养抗开裂超高性能混凝土的制备及性能研究

Preparation and performance evaluation of cracking resistance ultra-high performance concretewithout steam curing

为进一步提高超高性能混凝土(UHPC)抗开裂性能,降低生产制备中热养护所产生的能耗,通过复合掺入硫铝酸盐水泥(CSA)熟料制备了一种免蒸养抗开裂UHPC。基于最紧密堆积原理对UHPC原材料配合比进行设计,评价了UHPC的工作性能、力学性能、抗开裂性能。结果显示:制备的UHPC工作性能优异,随CSA熟料掺量的增加,UHPC的流动度减小,凝结时间缩短;CSA掺量为10%时,UHPC的流动度为240 mm,抗拉强度为7.848 MPa,28 d抗压强度为146.3 MPa,7 d总收缩值约为3000με,抗裂指数为11.23%。

In order to further improve the cracking resistance of ultra-high performance concrete(UHPC),and reduce the energy consumption generated by thermal curing in its production and preparation.This article developed a non-steam curing,and cracking resistant UHPC.Firstly,based on the closest packing theory,the raw material mix proportion of UHPC was designed,and then the working performance,mechanical properties,and crack resistance of UHPC were evaluated.The results showed that the prepared UHPC exhibited excellent performance.With the increase of CSA clinker content,the flowability of UHPC decreased and the setting time shortened.When the CSA content is 10%,the flowability of UHPC is 240 mm,the tensile strength is 7.848 MPa,the compressive strength at 28 days is 146.3 MPa,the total shrinkage value at 7 days is about 3000με,and the crack resistance index is 11.23%.