养护制度对超高性能混凝土微观结构和力学性能影响的研究综述

超高性能混凝土(UHPC)是指兼具超高抗渗性能和力学性能的纤维增强水泥基复合材料。在制备UHPC过程中,高温、加压的养护制度是UHPC获得高性能的重要手段。本文综述了不同的养护制度对UHPC基本力学性能和微观结构的影响,并分析其作用机理。研究表明,热养护加速了UHPC的水化过程,提高了材料的密实度,使其具有超高强度。在引入SiO₂组分下,热养护比标准养护使UHPC具有更致密的微观结构和更好的早期力学性能。但温度过高导致界面孔隙结构粗化和微裂纹产生,造成损伤,不利于UHPC的后期强度发展。本文旨在综合比较不同养护制度对UHPC力学性能和微观结构的影响,进而指导其生产和工程应用。

Review on Effects of Microstructure and Mechanical Properties of Ultra-High Performance Concrete by Curing Regimes

Ultra-high performance concrete (UHPC) is a fiber reinforced cement-based composite material with ultra-high permeability and mechanical properties. In the process of preparing UHPC, the curing regime of high temperature and pressure is an important measure for UHPC to obtain high performance. The basic mechanical properties and microstructure of UHPC with different curing regimes were reviewed, and the action mechanism of curing regime was analyzed. The research shows that thermal curing accelerates the hydration process of UHPC, improves the compactness of the material, and UHPC can obtain the ultra-high strength. With the introduction of SiO₂ component,UHPC has compact microstructure and good early mechanical properties under thermal curing compared with standard curing. However, excessively high temperature leads to coarsening and microcracks in the pore structure of the interface, resulting in interface damage, which is not conducive to the later strength development of UHPC. This paper aims to comprehensively compare the effects of different curing regimes on the mechanical properties and microstructure of UHPC, so as to guide the production and engineering application of UHPC.