摘要
沙漠地区风积沙具有结构松散、风稳定性差、承载力低、湿陷性强的特点,为了增强沙漠地区输电线路杆塔设施地基的稳固性,以塔克拉玛干沙漠风积沙为研究对象,对其进行水泥固化,并开展了固化前后风积沙试样的直剪试验。试验结果表明:2%、3%含水率条件下,掺入不同水泥含量的固化风积沙试样,其黏聚力随着水泥含量增加均出现先增大后减小的趋势,并在水灰比为0. 5左右时出现峰值,其内摩擦角无明显变化;同时,水泥固化前后试样的扫描电镜(SEM)和X射线衍射(XRD)测试结果表明:与固化前的风积沙相比,固化后的风积沙试样表面除水泥颗粒与孔隙外,出现了凝胶体和针状晶体,其中凝胶体和针状晶体堵塞了大量的孔隙,提高了试样表面密实程度;固化后的风积沙中经化学反应后生成C-S-H、Ca(OH)2、钙矾石等新矿物,其中胶凝物质C-S-H是充填风积沙骨架间孔隙的主要材料,也是增加水泥固化风积沙试样黏聚力的主要来源。
Aeolian sand in desert area is characterized by loose structure,no cohesion,poor stability and low bearing capacity.In order to enhance the stability of the transmission line tower foundation facilities in desert areas,the paper took the Taklamakan desert aeolian sand as the research object,using a certain proportion of water and cement reinforcing the aeolian sand specimens,then carrying out the direct shear test.The test results showed that the aeolian sand reinforced with cement‘cohesion increased and then decreasted with the increase of cement content when aeolian sand’moisture content was 2%and 3%,and the cohesion would have a peak when the ratio of moisture content to cement content was around 0.5,then the friction had no obvious change;at the same time,the scanning electron microscope(SEM)and X-ray diffraction(XRD)test results of the aeolian sand reinforced with cement showed that comparing with the aeolian sand without cement,the aeolian sand reinforced with cement sample not only had cement particle and pore,and appeared gels and acicular crystal,those gels and acicular crystal blocked a lot of pore and improved the compactness of sand;In aeolian sand reinforced with cement,new minerals such as C-S-H,Ca(OH)2 and calcium alunite were generated through chemical reaction,and the cementitious material C-S-H was the main material to fill the pores in sand and the main reason to improve the cohesion of aeolian sand reinforced with cement.
作者
金旻昊
崔强
周楠
何金业
程峰
褚忠凯
JIN Minhao;CUI Qiang;ZHOU Nan;HE Jinye;CHENG Feng;ZHU Zhongkai(School of Civil Engineering and Architecture,Zhejiang University of Science and Technology,Hangzhou 310023,China;China Electric Power Research Institute,Beijing 100192,China;Construction Branch of State Grid Xinjiang Electric Power Co.,Ltd.,Urumqi 830002,China;China Energy Construction Group,Xinjiang Electric Power Design Institute Co.,Ltd,Urumqi 830002,China)
出处
《工业建筑》
CSCD
北大核心
2019年第7期108-112,168,共6页
Industrial Construction
基金
国网新疆电力公司科技项目(GCB11201800899)
关键词
输电线路
塔克拉玛干沙漠
风积沙
水泥固化
抗剪强度
微观结构
transmission line
Taklamakan desert
aeolian sand
cement solidification
shear strength
microstructure
