生物聚合物固化粉土室内试验与机理研究

Laboratory Experiment and Mechanism of Solidified Soil of Biopolymer

传统的水泥土具有高碱性、原料生产碳排放高以及养护依赖水等缺点,且对西北地区的荒漠化具有不利的影响。以生物聚合物(黄原胶)为固化剂,展开室内试验研究其对西北粉土的固化效果及机理分析。研究表明:黄原胶作为生物聚合物固化粉土,相比素土具有更好的固化效果;采用干法拌合方式的试样强度高于湿法拌合;固化土的强度增长得益于黄原胶分子链与土体颗粒间的离子键作用,且随含水率降低而迅速增强,黄原胶分子牢固地吸附在土颗粒表面,起到极强的胶结作用。生物聚合物固化土具有中性环保、可再生的优点,在自然环境中脱水形成稳定强度,并具有保湿抗荒漠化的作用,尤其对于西北干旱地区具有很好的应用前景与研究价值。

Traditional cement soil is of high alkaline,high carbon emissions and dependency on water conservation,and also has adverse effects on the desertification in northwest region of China.Indoor experiment was conducted to investigate the curing effect of biopolymer (xanthan gum) on northwest silty soil and the curing mechanism.Compared with plain soil,xanthan gum as a biopolymer curing agent has good curing effect on silty soil.The compressive strength of dry-mixed soil is higher than that of wet-mixed soil.With the decrease of water content,the ionic bond strength between the molecular chain of xanthan gum and the soil particles increases rapidly,resulting in the growth in strength of solidified soil.The molecules of xanthan gum are firmly adsorbed on the surface of soil particles,playing a very strong cementation role.Moreover,biopolymer solidified soil is neutral,environmental-protecting and renewable,whose strength is formed in natural environment.It is of prominent application prospect and research value,for arid area of northwest China,in particular,as it has functions of moisturizing and anti-desertification.