胶结物对花岗岩残积土力学性能的影响试验研究  

Influence of cement on mechanical strength of administrator residual soil

作　　者：汤连生 贺云帆 孙银磊 许瀚升 TANG Liansheng;HE Yunfan;SUN Yinei;XU Hansheng(School of Earth Science and Engineering,Sun Yat-Sen University,Zhuhai 519082,Guangdong,P.R.China;School of Architecture and Planning,Yunnan University,Kunming 650504,P.R.China)

机构地区：[1]中山大学地球科学与工程学院,广东珠海519082 [2]云南大学建筑与规划学院,昆明650500

出　　处：《土木与环境工程学报(中英文)》2025年第2期30-38,共9页Journal of Civil and Environmental Engineering

基　　金：国家自然科学基金(42102303、42277142、41877229、41877228);广东省自然科学基金(2018B030311066,2019A1515010554);中国博士后科学基金(2019M663241);广州市科技计划项目(201904010136)。

摘　　要：胶结物对花岗岩残积土的力学性质有着重要的影响。以高岭石粉、蒙脱石粉、伊利石粉、红黏土粉代替花岗岩残积土细粒制作重塑土样,分别开展抗压、抗剪、抗拉及崩解试验,研究不同胶结剂对土体力学强度的影响。结果表明:经过高岭土处理的土体颗粒团聚体增多,团聚体之间形成了强度较高的骨架结构,但骨架间大量孔隙的存在为水的侵入提供了通道,导致土体的吸水性增强。受益于蒙脱石的遇水膨胀特性,其处理后的土体表面孔隙较少、结构密实,且膨胀体提供了高强度的胶结能力,使土体的各种力学性能得到明显改善。伊利石处理土样的各种力学强度都较低,但土体表面看起来比较密实,从土体表面分散的颗粒来看,伊利石粉更多是作为细粒材料填充大颗粒之间的孔隙,而不是作为强度较高的胶结物存在于土体颗粒之间。经过物理击实,由于受到压缩,颗粒之间咬合作用增强;同时,经过长时间的水化反应,胶结物在颗粒表面形成桥状胶结,在物理和化学的共同作用下,土体的力学强度得到大幅提升。胶结物的种类会对力学性能产生极大影响,一方面取决于其自身特性,如蒙脱石的遇水膨胀特性,另一方面取决于其对土体的结合作用,土样的抗压、抗剪、抗拉及抗崩解能力受制于胶结物与土样的结合方式。The cement has important influence on the mechanical properties of granite residual soil.Kaolinite powder,montmorillonite powder,illite powder and red clay powder are used to replace the fine particles of granite residual soil to remold soil samples.Compression,shear,tensile and disintegration tests are carried out respectively to study the effects of different cements on the mechanical strength of soil.Results show that the soil particle aggregates after kaolin treatment are increased,and a skeleton structure with high strength is formed between the aggregates.However,the existence of large number of pores between the skeletons provides a channel for water intrusion,resulting in enhanced water absorption of the soil.Benefiting from the swelling property of montmorillonite in water,the treated soil surface has fewer pores and dense structure,and the expansive body provides high strength cementation capacity,making the mechanical characteristics of soil significantly improved.The mechanical strength of the soil sample treated with illite is low,but the soil surface appears relatively dense.From perspective of particles dispersed on the soil surface,illite powder is more used as fine material to fill the pores between large particles than as a cement with high strength between soil particles.After physical compaction,the occlusion between particles is enhanced due to compression;At the same time,after a long time of hydration reaction,the cement formed bridge cementation on the particle surface.Under the combined actions above,the mechanical strength of soil has been greatly improved.The type of cement would have a great impact on the mechanical properties.On the one hand,it depends on the characteristics of the cement itself,such as the water swelling characteristics of montmorillonite.On the other hand,it depends on the binding effect of the cement on the soil.The compressive,shear,tensile and collapse resistance of the soil samples are controlled by the binding mode of the cement and the soil sample.

关 键 词：胶结物 花岗岩残积土 力学强度 微观结构 

分 类 号：TU443[建筑科学—岩土工程]