Water-induced changes in strength characteristics of polyurethane polymer and polypropylene fiber reinforced sand  

水对聚氨酯和聚丙烯纤维固化砂土强度特性的影响

作　　者：WANG Ying LIU Jin SHAO Yong MA Xiao-fan QI Chang-qing CHEN Zhi-hao 王颖;刘瑾;邵勇;马晓凡;祁长青;陈志昊(School of Earth Sciences and Engineering,Hohai University,Nanjing 210098,China;Jiangsu Taihu Lake Control Engineering Construction Administration,Department of Water Resources of Jiangsu Province,Wuxi 214000,China)

机构地区：[1]School of Earth Sciences and Engineering,Hohai University,Nanjing 210098,China [2]Jiangsu Taihu Lake Control Engineering Construction Administration,Department of Water Resources of Jiangsu Province,Wuxi 214000,China

出　　处：《Journal of Central South University》2021年第6期1829-1842,共14页中南大学学报（英文版）

基　　金：Project(41472241)supported by the National Natural Science Foundation of China;Project(KJXM2019028)supported by the Natural Resources Science and Technology Project of Jiangsu Province,China;Project(2019B17314)supported by the Fundamental Research Funds for the Central Universities,China。

摘　　要：As a new kind of air-hardening soil reinforcement material,polymer is being widely applied in river-bank slope reinforcement and ecological slope protection area.Thus,more attention should be paid to study the characteristics of reinforced soil after immersion.In this study,water-induced changes in strength characteristics of sand reinforced with polymer and fibers were reported.Several factors,including polymer content(1%,2%,3%and 4%by weight of dry sand),immersion time(6,12,24 and 48 h),dry density(1.40,1.45,1.50,1.55 and 1.60 g/cm^(3),)and fiber content(0.2%,0.4%,0.6%and 0.8%by weight of dry sand)which may influence the strength characteristics of reinforced sand after immersion were analyzed.The microstructure of reinforced sand was analyzed with nuclear magnetic resonance(NMR)and scanning electron microscope(SEM).Experimental results indicate that the compressive strength increases with the increase of polymer content and decreases with the increase of immersion time;the softening coefficients decrease with the increase of the polymer content and immersion time and increase with an increment in density and fiber content.Fiber plays an active role in reducing water-induced loss of strength at 0.6%content.聚合物作为一种新型气硬型土壤加固材料,在河道岸坡加固和生态护坡领域得到了广泛的应用。本文研究了水对聚合物和纤维加固后砂土强度特性的影响。对可能影响浸水后加固砂土的强度特征的几个因素进行了分析,包括聚合物含量(1%,2%,3%和4%与干砂的质量比),浸水时间(6,12,24和48 h),干密度(1.40,1.45,1.50,1.55和1.60 g/cm^(3))和纤维含量(0.2%,0.4%,0.6%和0.8%与干砂的质量比)。用核磁共振(NMR)和扫描电子显微镜(SEM)对加固砂土的微观结构进行了分析。试验结果表明,抗压强度随聚合物含量的增加而增大,随浸水时间的延长而减小;软化系数随聚合物含量的增加和浸泡时间的延长而减小,随密度和纤维含量的增加而增大。纤维含量为0.6%时,对减小水引起的强度损失有积极作用。

关 键 词：POLYMER fiber reinforced sand IMMERSION compressive strength softening coefficient 

分 类 号：S157[农业科学—土壤学]