木质素加固黄土的工程性能试验研究

发布时间：2019-02-15 12:32

【摘要】：黄土的水稳性较差,遇水容易产生崩解破坏,可造成黄土地区建筑物失稳。采用无侧限抗压强度试验、湿化崩解试验、单轴拉伸试验、三轴压缩试验和渗透试验,对木质素磺酸盐固化黄土的工程性质进行试验研究,探讨木质素磺酸盐加固黄土的可行性。试验结果表明,木质素磺酸钙可以改善黄土的工程性能,而木质素磺酸钠则相反;随着木质素磺酸钙掺量的增加,固化土的抗压和抗拉强度先增加后降低;含水率越小,密度越大,则固化土的强度越大;随着养护龄期的增长,固化土的强度先增加,而后趋于稳定。黄土在掺入木质素磺酸钙后,黄土的崩解特性显著改善,在掺量为1.0%和养护龄期为7 d时,几乎不发生崩解。木质素磺酸钙掺入土体后,渗透性降低。研究表明,木质素磺酸钙可显著改善黄土的工程性能。在工程应用中,建议在黄土中掺加1.0%的木质素磺酸钙,养护7 d。结合扫描电子显微镜观察,进一步分析木质素磺酸钙对土体工程性能产生影响的作用机制。木质素磺酸钙加固黄土的机制主要在于胶结土颗粒与填充孔隙两部分。
[Abstract]:The water stability of loess is poor, and it is easy to collapse and destroy when it comes to water, which can lead to the instability of buildings in loess area. The engineering properties of lignin sulfonate solidified loess were studied by unconfined compressive strength test, wet disintegration test, uniaxial tensile test, triaxial compression test and permeation test. The feasibility of strengthening loess with lignosulfonate was discussed. The results show that calcium lignosulfonate can improve the engineering properties of loess, but sodium lignosulfonate is the opposite, and the compressive strength and tensile strength of the cured soil increase first and then decrease with the increase of the content of calcium lignosulfonate. With the increase of curing age, the strength of solidified soil first increases and then tends to be stable. After adding calcium lignosulfonate into loess, the disintegration characteristics of loess were improved significantly. When the content was 1.0% and the curing age was 7 days, there was almost no disintegration. The permeability of calcium lignosulfonate decreased with the addition of calcium lignosulfonate into soil. The results show that calcium lignosulfonate can significantly improve the engineering properties of loess. In engineering application, it is suggested that 1.0% calcium lignosulfonate should be added to loess for 7 days. The mechanism of effect of calcium lignosulfonate on soil engineering performance was analyzed by scanning electron microscope (SEM). The mechanism of strengthening loess with calcium lignosulfonate mainly lies in two parts of cemented soil particles and filled pores.
【作者单位】：西北农林科技大学水利与建筑工程学院;中建八局第一建设有限公司;江苏建筑职业技术学院;
【基金】：陕西省科技统筹创新工程计划项目(No.2013KTDZ03-03-01) “十二五”国家科技支撑计划项目(No.2011BAD31B05-01-02)~~
【分类号】：TU444;TU472

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