稻壳灰-高炉矿渣固化膨胀土工程特性及机理  

Engineering characteristics and mechanism of rice husk ash-ground granulated blast slag cured expansive soil

作　　者：李丽华 李孜健[1,2] 肖衡林 黄少平 刘一鸣[1,2] LI Li-hua;LI Zi-jian;XIAO Heng-lin;HUANG Shao-ping;LIU Yi-ming(School of Civil Engineering,Architecture and Environment,Hubei University of Technology,Wuhan 430068,China;Key Laboratory of Health Intelligent Perception and Ecological Restoration of River and Lake,Ministry of Education,Hubei University of Technology,Wuhan 430068,China)

机构地区：[1]湖北工业大学土木建筑与环境学院,湖北武汉430068 [2]湖北工业大学河湖健康智慧感知与生态修复教育部重点实验室,湖北武汉430068

出　　处：《浙江大学学报（工学版）》2023年第9期1736-1745,共10页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(52278347,U22A20232);湖北省重点研发计划项目(2022BCA059);湖北工业大学杰出人才基金资助项目(XJ2021000501)。

摘　　要：为了改良膨胀土力学性能,提高其膨胀变形稳定性,通过无侧限抗压、自由膨胀率、扫描电镜和X射线衍射等方法,研究以工业固废稻壳灰-高炉矿渣(RHA-GGBS)为材料环保固化剂的膨胀土固化效果及机理.结果表明:固化剂对膨胀土力学性能有显著提升,当配比超过6∶4或RHA-GGBS质量分数超过10%时,力学性能不升反降.试样养护前后自由膨胀率降低原因不同,养护前为替换作用,养护后为水化反应。养护后的试样自由膨胀率降幅均高于未养护的,养护组较未养护组降幅最高为3.6倍.在10%RHA-GGBS质量分数临界值条件下,试样生成的团聚体、少量针棒状物及大量无定型凝胶均分布在土体的表面及孔隙;RHA-GGBS可提高土体强度,降低土体膨胀,RHA-GGBS质量分数超过临界值时,存在过量SiO_(2)无法反应,生成物总量限制,使得固化反应受到不同程度的抑制作用的影响.In order to improve the mechanical properties of expansive soil and improve its stability of expansion deformation,by means of unconfined compressive strength,free expansion rate,scanning electron microscopy and X-ray diffraction,the solidification effect and the mechanism of expansive soil with industrial solid waste rice husk ash-ground granulated blast slag(RHA-GGBS)as environmental curing agent were studied.Results show that the curing agent significantly improves the mechanical properties of expansive soil.When the ratio exceeded 6∶4 or the mass fraction of RHA-GGBS exceeded 10%,the mechanical properties did not increase but decrease.The reasons for the decrease of free expansion rate before and after curing are different.Before curing,it is a substitution effect,and after curing,it is a hydration reaction.The decrease of free expansion rate after curing was higher than that of uncured samples,and the decrease of free expansion rate after curing was 3.6 times higher than that of uncured samples.Sample generated agglomerates,small amount of needle stick and large amount of amorphous gel under the 10%RHA-GGBS mass fraction critical value conditions,which were distributed on the soil surface and fill the pores.RHA-GGBS can improve the strength of the soil body,reduce the expansion of the soil,RHA-GGBS mass fraction exceeds the critical value,there is an excess of SiO_(2) can not be reacted,by the total amount of product limitations,the curing is affected by varying degrees of inhibition.

关 键 词：固化/稳定化 稻壳灰-高炉矿渣(RHA-GGBS) 膨胀土 工程特性 固化机理 

分 类 号：TU443[建筑科学—岩土工程]