Study on Preparation and Strength of Foamed Lightweight Soil Mixed with Red Mud and Coal Gangue

本研究以工业固废资源化利用为核心理念，聚焦赤泥与煤矸石的高效协同利用技术，针对公路工程沉降防控、路基置换及脱空注浆加固等关键技术需求，成功开发出环境友好型固废基泡沫轻质土。通过对抗压强度、干密度等核心性能指标的系统测试，完成了材料配合比的科学优化。主要研究成果可归纳为：通过活性指数法研究赤泥与煤矸石在水泥泡沫轻质土进行定量表征。实验数据结果表明：赤泥与煤矸石在水泥基中的活性指数趋近，验证了作为辅助胶凝材料制备泡沫轻质土的技术可行性；通过单因素试验揭示材料性能的关键控制参数，分析得到各个因素对各个性能指标影响，确定赤泥和粉煤灰单因素的优化区间为：赤泥掺量5%~15%、煤矸石掺量5%~15%。本实验制备的泡沫轻质土可以有效地节约材料，提高材料的利用率，确保施工便捷高效。同时，该材料的强度优于标准的泡沫轻质土。Based on the core concept of resource utilization of industrial solid waste, this study focused on the efficient collaborative utilization technology of red mud and coal gangue. It addresses key technical needs in highway engineering, such as settlement control, subgrade replacement, and void grouting reinforcement. As a result, it has successfully developed an environmentally friendly solid waste-based foamed lightweight soil. Through systematic testing of core performance indexes such as compressive strength and dry density, the scientific optimization of the material mix ratio was completed. The main research achievements can be summarized as follows: The reactivity index method was employed to quantitatively characterize red mud and coal gangue in cement-based foamed lightweight soil. The experimental data show that the activity index of red mud and coal gangue in cement base is close to each other, which verifies the technical feasibility of preparing foamed lightweight soil as auxiliary cementing material. The key control parameters of material properties were revealed through a single factor test, and the influence of each factor on each performance index was analyzed. The optimal range of single factors for red mud and fly ash was determined as follows: red mud content 5%~15%, coal gangue content 5%~15%. The foamed lightweight soil prepared in this experiment can effectively save materials, improve the utilization rate of materials, and ensure convenient and fast construction. At the same time, the strength of the material is better than that of standard foamed lightweight soil.