甜菜碱处治膨胀土效果及机理研究  

Study on Effect and Mechanism of Using Betaine to Treat Expansive Soil

作　　者：殷志祥[1] 高哲[1] 冯瑶 谷松原[3] 

机构地区：[1]辽宁工程技术大学研究生院,辽宁阜新123000 [2]锦州市开发区财政投资评审中心,辽宁锦州121000 [3]同济大学道路与交通工程教育部重点试验室,上海201804

出　　处：《公路交通科技》2017年第3期1-6,14,共7页Journal of Highway and Transportation Research and Development

摘　　要：采用十二烷基三甲基胺乙内酯(甜菜碱)处治辽西某地膨胀土路基,以提高膨胀土路基结构强度。同时设计试验,揭示甜菜碱处治膨胀土的机理。在测定所用膨胀土基本物理性质参数的基础上,通过CBR试验、无侧限抗压试验、自由膨胀试验、干湿循环后的无侧限抗压试验等,验证甜菜碱对膨胀土的处治作用。试验结果表明甜菜碱能够提高膨胀土的强度和抵抗干湿循环的能力,同时降低膨胀土自由膨胀率,试验条件下的经济掺量为0.6%。此外根据双电层理论分析了甜菜碱处治膨胀土的机理。进而通过吸附试验和阳离子交换试验证明,甜菜碱分子内氮原子上的正电荷、长脂肪碳链、羧基均具有处治膨胀土的作用。Attempts are made to use dodecyl betaine to modify the expansive soil subgrades and enhance its structure strength in west Liaoning Province.Then,the experiments are designed to reveal the mechanism of using betaine to stabilize expansive soil.After testing the basic physical property parameter of the expansive soil,CBR,unconfined compression test,free swelling test,and unconfined compression test after wet-dry cycles are conducted to verify the treat effect of betaine on expansive soil.The test result shows that betaine has treat effect on expansive soil and the resistance to wet-dry cycling,and reduce the free swell ration.It has also been determined that the economic mass fraction to modify this certain expansive soil is 0.6%.Besides,the treat mechanism of betaine is analyzed based upon the ＂double electric cation layer theory＂.It is found and proved by adsorption test and cation exchange test that the positive charge on the nitrogen atom,long aliphatic carbochain,and carboxyl all contribute to improve the strength of expansive strength.

关 键 词：道路工程 膨胀土路基 离子交换试验 甜菜碱处治 膨胀土 吸附试验 

分 类 号：TU472.5[建筑科学—结构工程]