二氧化碳矿化养护混凝土技术及新型材料研究进展

Review on carbon dioxide mineral carbonation curing technology of concrete and novel material development

CO2矿化养护技术利用早期成型后的混凝土材料和CO2之间的碳酸化反应和产物沉积过程实现产品力学强度等特性的提升,主要关注的是预养护/早期水化成型后的混凝土中胶凝成分和CO2之间的矿化反应(即加速碳酸化)。此过程中胶凝材料的水化过程不再是强度形成的主要反应,因此为了充分实现矿化成型和CO2固定,实现环境效益最大化,研究者近几年积极开发具有CO2矿化潜力的碱金属矿物材料,并探究其反应后对于混凝土微观结构和性能的促进效应。本文综述了CO2矿化养护技术在新型混凝土材料方面的研究进展,分别对传统混凝土采用的水化活性硅酸钙材料、水化惰性硅酸钙材料、镁基水泥材料以及工业固废材料等进行了具体介绍,比较了在不同材料与CO2反应特性以及养护后建材制品性能优化方面的最新成果,并对CO2矿化养护技术的后续发展进行了展望。主要建议:一是着眼于微观反应机制和矿物材料特性,开发有效的矿化反应强化方法;二是开发水化惰性的低钙硅比硅酸钙材料;三是将工业固废资源化与矿化养护技术结合,实现固废和气废利用流程耦合,推进特定工艺开发和装置研发。

CO2 mineral curing technology is based on the carbonation reaction and product formation process between the early-formed concrete material and CO2 to improve the mechanical strength of concrete products.The development of CO2 mineral carbonation curing focuses on the mineralization reaction(i.e.,accelerated carbonation)between the binder materials and CO2 in the concrete after precuring/early hydration molding.In this process,the hydration process of the cementitious material is no longer the main reaction for the strength gain.Therefore,in order to fully realize the mineralization cementation and the CO2 fixation,and maximize the environmental benefits,researchers have widely explored the alkali metal materials with CO2 mineralization potential in recent years,and investigated the effect of mineralization reaction on the microstructure and properties of concrete.In this paper,the research progress of CO2 mineral carbonation curing technology on novel concrete materials is reviewed.The hydraulic calcium silicate materials used in traditional concrete,non-hydraulic calcium silicate materials,magnesium-based cement materials and industrial solid waste materials are considered and compared.The paper introduced the latest achievements on the CO2 reaction characteristics of different materials and the performance optimization of building materials after curing.The prospects for the future development of CO2 mineral carbonation technology are also summarized.The main suggestions include:firstly,focusing on the microstructure reaction mechanism and mineral properties,and developing effective reaction enhancement methods;secondly,developing the non-hydraulic calcium silicate materials;thirdly,combining the industrial solid waste recycling and the CO2 mineral carbonation processes to use solid waste and gas waste in one process,and developing the specific process and device.