再生集料固化CO_(2)影响因素研究进展

Research Progress of Influencing Factors on CO_(2) Solidification of Recycled Aggregate

再生集料固化CO_(2)是一种利用废旧混凝土中的氢氧化钙、C-S-H凝胶、未水化水泥颗粒等活性物质与CO_(2)反应,实现CO_(2)的捕集、固化与封存的技术。该技术将CO_(2)以稳定存在的碳酸盐形式固化在再生集料中,并通过再生集料的使用实现CO_(2)的封存,为减少CO_(2)排放提供一种可行的途径。再生集料的固碳量和固碳效率受诸多因素影响,近年来国内外学者在再生集料的固碳机理、再生集料固碳量的影响因素、提高再生集料固碳效率的工艺参数等方面,做了大量工作并取得了一定的研究成果。根据已有的研究成果,阐述了再生骨料固化CO_(2)的机理,并基于再生集料固碳量和固碳效率的视角,综述了再生集料的原生混凝土胶凝材料种类、水胶比、集料量、再生集料粒径等自身因素对再生集料固碳的影响规律,同时着重介绍环境温度、环境湿度、CO_(2)浓度、环境气压、碳化时间、再生集料含水率等环境条件对再生集料固碳的影响,并总结归纳了再生集料捕集固化CO_(2)的适宜环境参数。

Recycled aggregate solidification CO_(2) is a technology that utilize active substances such as calcium hydroxide,C-S-H gel,unhydrated cement particles and other active substances in waste concrete to react with CO_(2) to achieve the purpose of CO_(2) capture,solidification a nd storage.T his technology solidifies CO_(2) i n t he form of stable carbonate in recycled aggregates,and storages CO_(2) through the application of recycled aggregates,providing a feasible way to reduce application emissions.The carbonation rate and carbonation efficiency of recycled aggregates are influenced by many factors.In recent years,domestic and foreign scholars have done a lot of work on the carbonation mechanism of recycled aggregates,the influencing factors of carbonation rate,the process parameters to improve carbonation efficiency of recycled aggregates,have achieved certain research results.Based on existing research results,this article elaborated on the mechanism of CO_(2) solidification of recycled aggregates,and summarized the influence of factors such as the type of primary concrete cementitious material,water cement ratio,aggregate quantity,and particle size of recycled aggregates from the perspective of carbonation amount and carbonation efficiency of recycled aggregates.At the same time,the influence of environmental temperature,environmental humidity,CO_(2) concentration,environmental pressure,carbonization time,moisture content of recycled aggregateon carbonation of recycled aggregate were introduced,and the suitable environmental parameters for capturing and solidifying CO_(2) by recycled aggregate were summarized.