抗疏力固化剂改性黄土工程性质及其改性机制

发布时间：2018-08-16 19:40

【摘要】：将抗疏力固化剂运用到黄土加固中,并对比水泥、石灰改性黄土性质,探究抗疏力固化剂改性机制。通过强度试验、崩解试验、渗透试验探索改性土工程性质。通过开展水滴入渗、X衍射、电镜扫描、压汞等试验分别分析土样土颗粒表面能、矿物成分、微观结构、孔隙充填情况以探究改性机制。试验结果表明:抗疏力固化剂改性黄土强度、抗崩解性显著提高,渗透性略有降低。水滴入渗试验显示抗疏力改性黄土土颗粒表面自由能极大降低,斥水性明显优于水泥、石灰改性土;不同抗疏力固化剂添量土样X衍射图谱中物象群峰基本相同;SEM图像显示随抗疏力固化剂掺量提高,黄土中粉土颗排列方式基本不变,细小黏附物发生凝聚,附着物略有增多;压汞数据显示抗疏力改性黄土中大、中、小孔隙体积均略有减小,微孔隙明显增多。初步得出抗疏力改性黄土的机制在于:降低土颗粒表面能以提高阻水、抗水性;抗疏力物质包裹土颗粒及细小黏土颗粒发生凝聚来连结土颗粒,强化骨架颗粒连结强度;抗疏力材料膨胀挤密作用较弱,改性黄土通透性好。抗疏力固化剂在改善黄土力学性质、水理性质的基础上,还一定程度上解决了传统固化剂在提高阻水性的同时通透性降低的矛盾。
[Abstract]:The anti-thinning agent was applied to loess reinforcement, and the properties of loess modified by cement and lime were compared, and the modification mechanism of anti-thinning agent was explored. The engineering properties of modified soil were explored by strength test, disintegration test and permeation test. The surface energy, mineral composition, microstructure and pore filling of soil samples were analyzed by X-ray diffraction, scanning electron microscope, mercury injection and so on. The test results show that the strength of loess modified by anti-thinning agent is obviously improved, and the permeability is slightly decreased. The water drop infiltration test showed that the surface free energy of the modified loess soil was greatly reduced, and the water repellency was obviously better than that of the cement and lime modified soil. In the X-ray diffraction pattern of soil samples with different amount of anti-thinning agent, the image group peaks are basically the same. The SEM images show that with the increase of the content of anti-thinning agent, the arrangement of silt particles in loess is basically unchanged, the fine adhesives are condensed, and the appendages are slightly increased. The mercury injection data showed that the pore volume of the modified loess with resistance to hydrophobicity decreased slightly and the micropore increased obviously. The mechanism of anti-hydrophobicity modified loess is as follows: reducing the surface energy of soil particles to improve water resistance and water resistance, condensing soil particles and fine clay particles to link soil particles and strengthening the connection strength of skeleton particles; The dilatation and compaction effect of the anti-thinning material is weak, and the permeability of modified loess is good. On the basis of improving the mechanical and hydrological properties of loess, the anti-hydrophobicity curing agent solves the contradiction that the traditional curing agent can improve the water resistance and decrease the permeability to some extent.
【作者单位】：兰州大学土木工程与力学学院;兰州大学西部灾害与环境力学教育部重点实验室;
【分类号】：TU444

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