棉杆纤维轻量土持水特性与冻融特性研究  

Research on Characteristics of Water-holding and Freeze-thaw of Light-weight Cotton Stalk Fiber Soil

作　　者：杜磊 Du Lei(The First Engineering Co.,Ltd.of China Railway 18th Bureau Group,Zhuozhou 072750,China)

机构地区：[1]中铁十八局集团第一工程有限公司,河北涿州072750

出　　处：《市政技术》2021年第1期145-149,共5页Journal of Municipal Technology

摘　　要：针对路面地基换填土层,设计掺棉杆纤维轻量土作为换填材料,开展离心吸力试验与冻融循环试验,研究了轻量土持水特性与抗冻特性。探讨了棉杆纤维轻量土持水特性受水泥含量、棉杆纤维含量的影响规律,全过程含水量随吸力呈"不变-快降"变化,吸力10 kPa为含水量变化拐点;对比得知轻量土与黄土在吸力40 kPa临界点前,黄土含水量高于轻量土,临界点后则相反。研究发现轻量土密度、强度和冻融循环次数呈递减至稳定变化;高冻融循次数下参数稳定,循环次数在前10次时,抗压强度降低幅度为34.2%,之后强度稳定在63.5 kPa。该研究成果可为棉杆纤维轻量土在路面地基中设计应用提供一定参考。For the soil-replacement of the pavement foundation,lightweight cotton stalk fiber soil(hereafter as LCSFS)is designed to be the replacement material.Centrifugal suction test and freeze-thaw cycle test are carried out to study the water retention and frost resistance of the lightweight soil.The water-holding properties of LCSFS are affected by cement content and cotton stalk fiber content.During the whole process The water content changes with the suction force from unchanging to rapidly decreasing and its inflection point is suction force 10 kPa;Making a comparison between loess and light-weight soil,the water content of the loess is higher than that of light soil before the critical point of suction 40 k Pa,and the opposite occurs after the critical point.The density and strength of lightweight soil and the number of freeze-thaw cycles change from decreased to be stable.The parameters are stable under high freeze-thaw cycles.Before the first 10 times of cycles,the compressive strength decreases by 34.2%,and after that,the strength stabilizes at 63.5 kPa.The thesis provides a certain reference for application and design of CSFLS in pavement foundation.

关 键 词：棉杆纤维 轻量土 持水特性 冻融循环 

分 类 号：U414[交通运输工程—道路与铁道工程]