特种骨料混凝土的研究进展

Research Progress of Special Aggregate Concrete

骨料是水泥混凝土的主要组成,随着水泥混凝土技术的发展与应用场景的拓展,某些基本性能、表面状态与天然砂石骨料有较大差异的特种骨料逐渐引起人们的重视。例如通过使用轻质/重骨料是满足高层与大跨结构、桥梁悬臂施工、建筑地基抗浮等重大工程对混凝土特殊密度需求的主要手段。同时,利用再生骨料替代天然骨料制备再生骨料混凝土,可有效解决天然砂石资源匮乏与废弃物混凝土资源化利用的问题。这些特种骨料在应用过程中存在着某些共性的科学与技术问题,所配制混凝土的性能、界面过渡区结构、施工特性等与普通水泥混凝土有着显著的区别。本文综述了轻骨料混凝土、重混凝土以及再生骨料混凝土三类特种骨料混凝土的研究进展与发展趋势,重点介绍了特种骨料的性质、混凝土界面过渡区结构与混凝土施工性能等方面的技术现状,最后对上述特种骨料混凝土的未来发展方向提出一定的建议。

Aggregate is the major component of concrete.With the development of concrete technology and the expansion of application scenarios,some special aggregates whose basic properties and surface conditions are quite different from those of natural aggregates have gradually attracted wide attention.For example,the use of lightweight/heavyweight aggregates is the main method to meet the special density requirements of major construction projects such as high-rise and long-span structures,bridge cantilever construction,and building foundation anti-floating.Besides,the use of recycled aggregates instead of natural aggregates to prepare recycled aggregate concrete can effectively solve the problems of the shortage of natural aggregate resources and the recycling utilization of waste concrete.There are some common scientific and technical problems during the application of these special aggregates.The performance,microstructure,and construction characteristics of concrete prepared with these special aggregates are significantly different from those of ordinary concrete.This study reviews the research progress and development trend of three types of special aggregate concrete including lightweight aggregate concrete,heavyweight concrete and recycled aggregate concrete.The research on the aggregates properties,the interfacial transition zone(ITZ)and construction technology are highlighted.The suggestions on the development trend of the above concrete are also proposed.