Hydration, Microstructure and Mechanical Properties of the Research Progress of Ultra-High-Performance Concrete

超高性能混凝土(Ultra-High Performance Concrete，简称UHPC)是一种具有超高强度、高韧性、低孔隙率的超高强水泥基材料，具有抗渗、抗疲劳和高耐久的特点。尽管UHPC拥有很多显著的优点，但也存在一些缺陷。例如其胶凝材料的用量高达1000 kg/m3，这增大了水化热，产生收缩，提高了工程造价。生产超高性能混凝土时往往采用蒸汽或蒸压养护，复杂的生产工艺限制了UHPC在实际工程中的应用。为了更好的研究UHPC材料，本文基于国内外已有的研究成果，介绍了UHPC的发展历史和研究现状，总结了UHPC凝结硬化的水化过程、微观结构、力学性能和耐久性能的研究现状，并对纤维增强增韧机理细观力学分析。结果发现，UHPC在理论研究与工程应用方面都取得了可喜的进展，随着我国对环保的日益重视，UHPC有着广阔的应用前景。 Ultra-High Performance Concrete (UHPC) is an ultra-high strength cement-based material with ultrahigh strength, high toughness and low porosity. It has the features of impermeability, fatigue resistance and high durability. Although UHPC has many significant advantages, there are some examples of defects, such as the amount of cementitious materials up to 1000 kg/m3, which in-creases the heat of hydration, results in shrinkage and improves the project cost. The production of ultra-high performance concrete often adopts steam or autoclave curing, and the complicated production technology limits the application of UHPC in practical engineering. In order to better study the UHPC material, this paper introduces the development history and research status of UHPC based on the existing research results at home and abroad, summarizes the current research status of UHPC condensation hardening process hydration process, microstructure, mechanical properties and durability, analyzes meso-mechanics of fiber reinforced toughening mechanism. The results show that UHPC has made gratifying progress in both theoretical research and engineering applications. With the increasing emphasis on environmental protection in China, UHPC has broad application prospects.