生物炭水泥土渗透特性试验及细观结构分析  

Permeability test and meso-structure analysis of biochar-cement soil

作　　者：刘忠玉[1] 黄通通 曹永青 刘朝凡 LIU Zhong-yu;HUANG Tong-tong;CAO Yong-qing;LIU Chao-fan(School of Civil Engineering,Zhengzhou University,Zhengzhou,Henan 450001,China)

机构地区：[1]郑州大学土木工程学院,河南郑州450001

出　　处：《岩土力学》2024年第10期2929-2936,共8页Rock and Soil Mechanics

基　　金：国家自然科学基金(No.51578511);河南省科技攻关项目(No.232102320352)。

摘　　要：为拓展生物炭在土木工程领域的应用,用生物炭代替部分水泥制作生物炭水泥土。采用室内变水头渗透试验和扫描电镜(scanning electron microscope,简称SEM)试验,分析不同生物炭掺量和养护龄期等条件下的渗透特性规律及其作用机制,寻找最佳生物炭掺量。渗透试验结果表明,随着生物炭掺量的增大,水泥土渗透系数先减小后增大,并在生物炭替代水泥量为1%时试样渗透系数最小。另外,随着龄期的增加,水泥土渗透系数非线性减小,其中生物炭对水泥土早期的渗透性影响最大。细观分析发现,生物炭在水泥土中并没有直接发生化学反应,生物炭之所以能提升水泥土的抗渗性能是由于生物炭填塞在土及水泥颗粒的孔隙中,使其更加密实。To expand the application of biochar in civil engineering,biochar was used to partially replace cement in biochar-cement soil.The permeability characteristics and mechanism of biochar-cement soil with different biochar contents and curing ages were analyzed using the falling head permeability test and scanning electron microscope(SEM)test to determine the optimal biochar content.The permeability test results showed that the permeability coefficient of cement soil decreased first and then increased with the increase of biochar content.The lowest permeability coefficient was observed when biochar replaced 1%of the cement.Additionally,the permeability coefficient of cement soil decreased nonlinearly with the increase of curing age,and biochar had the greatest influence on permeability of cement soil in the early stage.Meso-structure analysis revealed that biochar did not participate in chemical reactions within the cement soil.Biochar improved the anti-permeability performance of cement soil by filling the pores between soil and cement particles,making the mixture more compact.

关 键 词：生物炭 水泥土 渗透性 变水头渗透试验 扫描电镜试验 细观结构 

分 类 号：TU411[建筑科学—岩土工程]