钢渣碳酸化制备新型绿色加气混凝土制品结构与性能研究

Structure-performance relationship research on new green aerated concrete products by steel slag carbonation technology

以钢渣为骨料、铝粉为发泡剂,采用碳酸化工艺制备加气混凝土制品,考察制品的微观结构和发泡性能,并探究其“微观结构”与“宏观性能”之间的构效关系。经研究发现:(1)钢渣加气混凝土制品采用铝粉发泡工艺,发泡性能良好,孔隙率可达87.5%;(2)铝粉发泡钢渣浆体水化过程中形成了水化硅酸钙(C-S-H)凝胶,这种凝胶嵌入单碳型水化碳铝酸钙晶体间隙,从而形成稳定的凝胶-网络框架结构,大大增强了钢渣粒子之间的粘结强度,不但提高了浆体的稳泡能力,而且提高了制品的抗压强度(最高可达1.01MPa);(3)钢渣加气混凝土碳酸化反应后,因形成了“凝胶网络-棒状晶体”纠缠结构,显著提升了制品的抗压强度等级(达到C1.0级别)。该研究不仅能大量消耗钢渣废弃物,而且能够实现二氧化碳的长期固定,生产出成本低廉品质优良的碳酸化钢渣建材制品,符合国家环保降碳、节能减排的政策要求。

This article uses steel slag as aggregate and aluminum powder as foaming agent to prepare aerated concrete products using carbonation technology.The microstructure and foaming performance of the products are examined,and the structure-activity relationship between their"microstructure"and"macroscopic performance"is explored.Through this research,it has been found that as follows:(1)steel slag aerated concrete products use aluminum powder foaming technology,which has good foaming performance and a porosity of 87.5%;(2)During the hydration process of the aluminum powder foaming steel slag slurry,the hydrated calcium silicate(C-S-H)gel is formed.This gel is embedded into the single carbon type calcium carbide aluminate hydrate crystal gap,thus forming a stable gel network framework structure,greatly enhancing the bonding strength between steel slag particles,not only improving the foam stability of the slurry,but also improving the compressive strength of the product(up to 1.01MPa);(3)After carbonation reaction of steel slag aerated concrete,the compressive strength grade of the product(up to C1.0)was significantly improved due to the formation of"gel network rod crystal"entanglement structure;This research can not only consume a large amount of steel slag waste,but also achieve long-term fixation of carbon dioxide,producing low-cost and high-quality carbonated steel slag building materials products,meeting the national policy requirements of environmental protection and carbon reduction,energy conservation and emission reduction.