摘要
为提高铝工业固废赤泥的资源利用率,利用拜耳法赤泥部分替代水泥制备赤泥基泡沫轻质土。通过设计正交试验,分析赤泥掺量、湿密度、水胶比等因素对赤泥基泡沫轻质土流动性、不同龄期无侧限抗压强度及微观结构的影响。试验结果表明:对赤泥基泡沫轻质土无侧限抗压强度影响最显著的因素是湿密度和赤泥掺量;对流动性影响最显著的因素是水胶比和赤泥掺量;采用功效系数法确定的最优因素水平组合为赤泥掺量20%、湿密度1000 kg/m^(3)、水胶比0.4。SEM分析结果表明:赤泥基泡沫轻质土的水化产物主要为针棒状的钙钒石和水化硅酸钙,湿密度的变化对细观孔隙结构的分布及数量有显著影响;增加赤泥掺量可促进水化产物的生成,提高赤泥基泡沫轻质土的强度。试验段现场检测结果表明:赤泥基泡沫轻质土作为一种新型固废基轻质路基填料,其流动性和无侧限抗压强度均满足设计要求。
In order to improve the utilization rate of solid waste red mud produced by aluminum industry,the Bayer red mud was reused to partially replace cement to prepare red mud-based foamed lightweight soil.The influence of red mud content,wet density and water-binder ratio on the fluidity,unconfined compressive strength at different ages and microstructure features of red mud-based foamed lightweight soil were analyzed through orthogonal experiments.Results show that the most significant factors affecting the unconfined compressive strength of red mud-based foam lightweight soil are wet density and red mud content;the most significant factors affecting the fluidity of red mud-based foam lightweight soil are the water-binder ratio and the content of red mud.The optimal factor level considering the fluidity and unconfined compressive strength is determined by the efficiency coefficient method,which is red mud content of 20%,wet density 1000 kg/m^(3),water-binder ratio 0.4.The results of SEM analysis show that the hydration products of red mud-based foamed lightweight soil are mainly needle-like ettringite and calcium silicate hydrate,and the change of wet density has a significant effect on the distribution and quantity of pore structure.The increasing content of red mud can promote the formation of hydration products and improve the strength of red mud-based foam lightweight soil.The on-site field test results show that as a new type of lightweight subgrade filler,properties of red mud-based foam lightweight soil can meet the design requirements in terms of fluidity and unconfined compressive strength.
作者
成浩
杨腾宇
丁思尹
CHENG Hao;YANG Tengyu;DING Siyin(Foshan Transportation Science and Technology Co.Ltd.,Foshan 528000,China;Guangdong Shengrui Science and Technology Co.Ltd.,Guangzhou 511400,China)
出处
《新型建筑材料》
2022年第12期51-56,共6页
New Building Materials
关键词
拜耳法赤泥
泡沫轻质土
正交试验
功效系数法
Bayer red mud
foamed lightweight soil
orthogonal test
efficiency coefficient method
