大流动性免蒸养UHPC150的制备研究  

Study on the Preparation of UHPC150 with High Fluidity and Non-steam Curing

作　　者：王涛 

机构地区：[1]铁正检测科技有限公司,山东济南250014

出　　处：《混凝土世界》2024年第8期40-43,共4页China Concrete

基　　金：2021年中铁十四局集团科研课题《UHPC超高性能混凝土制备及性能研究》(91370000163055989120)。

摘　　要：本文采用紧密堆积理论,在前期制备的UHPC130配合比的基础上,通过调整胶凝材料组合,增加矿粉组成四元胶凝材料体系,研究不同的矿粉目数、石英砂级配和钢纤维种类对UHPC性能的影响,得到优化后的UHPC配合比,在常温状态下成功制备UHPC150。研究结果表明:添加的矿粉越细,UHPC的强度越高,其扩展度随着目数的增大而降低,当矿粉目数达到7000目时,UHPC的扩展度不再缩小;四级配石英砂会降低UHPC的扩展度,提升其各龄期的抗压强度,UHPC的28 d抗压强度大于150 MPa;凹痕型钢纤维能提高UHPC的韧性,但对其抗压强度的提升作用不明显;最终制备的UHPC150的配合比为超细粉∶水泥∶硅灰∶矿物降粘剂∶石英砂(10~20目)∶石英砂(20~40目)∶石英砂(40~80目)∶石英砂(80~120目)∶凹痕型钢纤维∶外加剂∶水=70∶750∶100∶200∶96∶193∶483∶193∶156∶21∶187,其扩展度大于640 m m,28 d抗压强度大于150 MPa。This article adopts the theory of close packing and based on the previously prepared UHPC130 mix propor tion,adjusts the combination of cementitious materials to increase the composition of mineral powder in a quaternary cementitious material system,studies the effects of different mineral powder mesh numbers,quartz sand gradation,and steel fiber types on the performance of UHPC and obtaines the optimized UHPC mix proportion,achieving the successful preparation of UHPC150 at room temperature.The results show that the finer the addes mineral powder,the higher the strength of UHPC,and its expansion degree decreases with the increase of fineness.When the fineness reaches 7000 mesh,the expansion degree of UHPC no longer decreased;four graded quartz sand can reduce the expansion of UHPC and improve its compressive strength at various ages,the 28 days compressive strength of UHPC is greater than 150 MPa;dented steel fibers can improve the toughness of UHPC,but their effect on enhancing its compressive strength is not significant.The final preparation ratio of UHPC150 is ultrafine powder∶cement∶silica fume∶mineral viscosity reducer∶quartz sand(10~20 mesh)∶quartz sand(20~40 mesh)∶quartz sand(40~80 mesh)∶quartz sand(80~120 mesh)∶dented steel fiber∶admixture∶water=70∶750∶100∶200∶96∶193∶483∶193∶156∶21∶187,with an expansion greater than 640 mm and a compressive strength greater than 150 MPa at 28 days.

关 键 词：超高性能混凝土 超细粉 级配 凹痕型钢纤维 

分 类 号：TU528[建筑科学—建筑技术科学]