摘要
超高性能混凝土(ultra-high performance concrete,UHPC)是一种力学性能、耐久性能优异的新型水泥基复合材料,但其较大的早期收缩,制约着UHPC的进一步应用。普通混凝土膨胀剂并不适用于超低水胶比UHPC的收缩,而氧化镁膨胀剂(MgO expansive agent,MEA)是一种需水量小、水化产物稳定的膨胀剂,可以用来补偿UHPC的收缩。首先综述了MEA的水化特性,对不同活性的MEA水化规律进行了总结,最后综述了MEA添加至UHPC对其工作性能、力学性能和体积稳定性的影响,并对超低水胶比条件下,MEA在胶凝体系中的补偿机理进行了分析,以期为MgO基减缩型UHPC的应用提供参考。
Ultra-high performance concrete(UHPC)is a new type of cementitious composite material with excellent mechanical properties and durability,but its large early shrinkage restricts the further application of UHPC.Ordinary concrete expansion agent is not applicable to the shrinkage of ultra-low water-to-cement ratio UHPC,while magnesium oxide expansive agent(MgO expansive agent,MEA)is a kind of expansion agent with small water requirement and stable hydration products,which can be used to compensate the shrinkage of UHPC.Firstly,the hydration characteristics of MEA were reviewed,and the hydration laws of MEA with different activities were summarized.Finally,the effects of MEA added to UHPC on its workability,mechanical properties and volumetric stability were reviewed,and the compensation mechanism of MEA in the gelling system under the condition of ultra-low water-to-cementitious ratio was analyzed,with a view to providing a reference for the application of MgO-based shrinkage re‐ducing UHPC.
作者
张大伟
黄兴启
刘凯强
陈平
明阳
ZHANG Dawei;HUANG Xingqi;LIU Kaiqiang;CHEN Ping;MING Yang(Shandong High-Speed Railway Construction Equipment Co.,Ltd.;School of Civil Engineering,Guilin University of Technology)
出处
《广东建材》
2024年第4期162-164,共3页
Guangdong Building Materials
