快硬UHPC的研发及其在道路快速维养工程中的示范应用

Development of rapid hardening UHPC and its application in road rehabilitation

基于市政快速维养工程需求开发了一种硅酸盐水泥基快硬UHPC,通过对拌合物黏度的调控,使其具有优异的工作性且钢纤维分散均匀无结团,在保持30 min以上可操作时间的前提下,2 h抗压强度大于30 MPa、抗折强度大于10 MPa,28 d抗压强度大于150 MPa,抗拉强度大于5 MPa,长龄期强度可持续发展,R90/R28抗压强度比大于105%。快硬UHPC不仅可满足快速维养施工需求,同时可克服传统快硬材料由于质量不稳定、脆性大、后期强度倒缩等耐久性不佳缺陷导致的反复维养问题。研究成果已成功应用于浦东新区张杨路道路快速维养工程,结合专用车载集成式搅拌设备的应用,降低了施工现场劳动作业强度,大幅提高了制备效率。

Based on the demand of municipal rapid maintenance project,a kind of Portland cement-based rapid hardening UHPC has been developed successfully.By adjusting the viscosity of the mixture,it has excellent workability and the steel fiber is evenly distributed without agglomeration.Under the premise of maintaining the workable time for more than 30 minutes,the 2 h compressive strength is greater than 30 MPa,the 2 h flexural strength is greater than 10 MPa,the 28 d compressive strength is greater than 150 MPa,and the tensile strength is greater than 5 MPa.Meanwhile the compressive strength ratio of R90/R28 is more than 105%which means it has long time continuous hydration characteristic.The research results can not only meet the needs of fast maintenance construction,but also overcome the repeated maintenance problems caused by the poor durability defects of traditional fast hardening materials,such as unstable quality,high brittleness and later strength shrinkage.The research products have been successfully applied to the Zhangyang road rapid maintenance project in Pudong Shanghai.Combined with the development of special vehicle integrated mixing equipment and the application of demonstration project,the labor intensity is lower,the preparation efficiency is greatly improved.