制备工艺对超高性能混凝土工作性能与抗压强度的影响

Effects of preparation process on workabilty and compressive strength of ultra high performance concrete

随着对建筑材料力学性能和耐久性能要求的日益增长,超高性能混凝土(Ultra High Performance Concrete,UHPC)逐渐成为了建筑工业领域的研究热点.国内外关于UHPC的力学性能已有许多报导,但缺少对其搅拌工艺的研究,导致UHPC在工程上推广应用有一定的局限性.本研究以强度等级为150~200 MPa的UHPC为研究对象,探讨不同制备工艺和制备设备对UHPC工作性能和抗压性能的影响,在此基础上,给出该类UHPC制备方法的建议.试验研究结果表明:UHPC是多相级配高致密材料,制备工艺对于其工作性能与抗压强度影响显著;二次搅拌工艺较传统搅拌工艺更能提高UHPC的搅拌质量和效率;实际水胶比的控制以及材料的均匀搅拌是保证UHPC工作性能和力学性能的关键。

With the increasing requirements on the mechanical properties and durability of building materials,ultra high performance concrete(UHPC)has gradually become a research hotspot in construction industry.Many studies have been conducted on the mechanical properties of UHPC,however,the lack of research on its effective mixing method has limited the promotion and application of UHPC.In this study,the influence of different preparation process and mixer equipment was investigated on the workability and compressive strength of the UHPC,which has a compressive strength of 150~200 MPa.Based on the experimental results,the suggestions of preparation method were proposed for this kind of UHPC.The results show that mixing process has significant influence on its workability and compressive strength,as UHPC is constituted of multiphase material.Compared with the traditional preparation process,the method of two-mixing process can further improve the mixing quality and efficiency of UHPC.Moreover,the controlling of the actual water-binder ratio and the uniform mixing of materials are the keys to ensure the performance of UHPC.