摘要
为研究新型超疏水材料改性黄土的疏水机理及其在长期浸水饱和条件下的强度演化特性,开展14 d浸水饱和条件下改性土的无侧限压缩试验、土水接触角试验、斥水试验,并基于SEM、XRD测试结果结合Image J、Jade等图像处理软件,对超疏水材料改性黄土的疏水机理及强度演化特性进行研究。试验结果表明,超疏水材料在土颗粒表面与极性的羟基发生键合反应,去除亲水的羟基并将非极性的有机硅牢牢键和在固体表面,形成纳米级硅颗粒状薄膜,大大改善了土体的水敏性;在长期浸水饱和条件下,2%及以上掺量改性土未发生崩解现象,低掺量(2%~6%)改性土强度随掺量成倍增长,6%掺量强度约达到1 MPa;素黄土试样约5 s水滴完全渗入,水滴与土体接触面积大,土水接触角约20.5°,属于亲水性土,3%及以上掺量改性土水滴团聚性显著,均表现为超级斥水性土,4%掺量下土水接触角为127.1°,约为素黄土的6.2倍;扫描电镜试验表明,素黄土微观孔隙形态分形维数为2.784,4%与8%改性土微观孔隙形态分形维数减小为1.286与1.244,XRD试验表明改性土矿物晶面间距较素黄土同样减小,说明改性土粒间孔隙进一步减少,团聚性更强。研究成果有助于揭示超疏水改性黄土疏水机理及强度演化特征,为黄土地区工程建设提供一定参考。
In order to study the hydrophobic mechanism of new superhydrophobic materials modified loess and its strength evolution characteristics under long-term saturation conditions,unconfined compression tests,soil water contact angle tests,and water repellent tests were conducted on modified loess under 14 day immersion saturation conditions.Based on SEM and XRD test results combined with image processing software such as Image J and Jade,the hydrophobic mechanism and strength evolution characteristics of superhydrophobic materials modified loess were studied.The experimental results show that superhydrophobic materials undergo bonding reactions with polar hydroxyl groups on the surface of soil particles,removing hydrophilic hydroxyl groups and firmly bonding non-polar organic silicon to the solid surface,forming nanoscale silicon particle like films,greatly improving the water sensitivity of soil.Under long-term water saturation conditions,the modified soil with a dosage of 2%or more do not experience disintegration.The strength of low dosage(2%~6%)modified soil can increase exponentially with the dosage,and the strength of 6%dosage reached about 1MPa.The pure loess sample has been completely infiltrated by water droplets for about 5 seconds,with a large contact area between the water droplets and the soil,and a soil water contact angle of about 20.5°.It belongs to hydrophilic soil,and the water droplet aggregation of 3%or more modified soil is significant,all exhibiting super hydrophobic soil.The soil water contact angle is 127.1°at a 4%dosage,which is about 6.2 times that of pure loess.The scanning electron microscopy tests show that the fractal dimension of the micro pore morphology of loess is 2.784,while the fractal dimension of the micro pore morphology of 4%and 8%modified soil decreased to 1.286 and 1.244.The XRD tests show that the crystal plane spacing of modified soil minerals is also reduced compared to loess,indicating that the inter particle pores of modified soil are further reduced and the agglomeration is stronger.The research results can contribute to revealing the hydrophobic mechanism and strength evolution characteristics of superhydrophobic modified loess,providing certain reference for engineering construction in loess areas.
作者
陈伟
韩建红
徐宏
余宏宝
陈俊礼
陈俊智
王滢
杨琴琴
CHEN Wei;HAN Jianhong;XU Hong;YU Hongbao;CHEN Junli;CHEN Junzhi;WANG Ying;YANG Qinqin(School of Civil Engineering,Xinjiang University of Engineering,Urumqi 830023,China;National Key Laboratory of Fine Coal Exploration and Intelligent Development,Xuzhou 221000,China;School of Mining Engineering and Geology,Xinjiang University of Engineering,Urumqi 830023,China;Xinjiang Gangcheng Tuorui Engineering Technology Co.,Ltd.,Urumqi 830000,China;Key Laboratory of Green Mining of Coal Resources in Xinjiang,Ministry of Education(Xinjiang University of Engineering),Urumqi 830023,China)
出处
《铁道科学与工程学报》
北大核心
2025年第5期2140-2150,共11页
Journal of Railway Science and Engineering
基金
新疆维吾尔自治区大学生创新创业训练计划项目(S202410994015)
中国矿业大学煤炭精细勘探与智能开发全国重点实验室-新疆工程学院联合基金资助项目(SKLCRSM-XJIE24KF001)
自治区高校基本科研业务费资助项目(XJEDU2024P085)
国家自然科学基金资助项目(41662017)。
关键词
黄土
超疏水材料
水稳定性
强度
微观机理
loess
superhydrophobic materials
water stability
strength
micro-mechanism
