初始含水率对石灰改性黏土强度的影响及微观机理研究  

Effect of Initial Water Content on Strength and Microcosmic Mechanism of Lime-modified Clay

作　　者：方立智 FANG Lizhi(Beijing Jianbang Shunkang Real Estate Development Co.,Ltd.,Beijing 101313,China)

机构地区：[1]北京建邦顺康房地产开发有限公司,北京101313

出　　处：《粉煤灰综合利用》2023年第1期27-31,共5页Fly Ash Comprehensive Utilization

摘　　要：为研究不同初始含水率下石灰改性黏土的无侧限抗压强度随时间的发展规律,基于击实试验确定的最佳含水率,制备不同含水率的石灰改性黏土试件进行无侧限抗压强度试验,分析初始含水率对石灰改性黏土的影响及机理。结果表明:无侧限抗压强度峰值点对应的含水率为23%,与击实试验确定的黏土最佳含水率20%不一致,较最佳含水率高3%左右;不同初始含水率下,石灰改性黏土的无侧限抗压强度受到黏结强化与水膜弱化的双重影响,且黏结强化与养护时间有关,随着养护时间的增加大致呈现为增强趋势;从微观结构来看,掺加石灰后,黏土的微观颗粒与微观孔隙均变小,颗粒黏结增强;与含水率20%石灰改性黏土相比,含水率23%的石灰改性红黏团聚体数量变多,石灰与黏土矿物的反应更为充分。In order to study the development law of unconfined compressive strength of lime-modified elay with diferent initial water content over time,based on the optimum water content determined by compaction test,lime-modifed clay samples with diferent water content were prepared for unconfined compressive strength test,and the influence mechanism of initial water content on lime-modified clay was analyzed.The results show that the moisture content corresponding to the peak point of unconfined copressive strength is 23%,which is not consistent with the optimal moisture content of clay determined by compaction test of 20%,and is about 3%higher than the optimal moisture content.Under dfferent initial water content,the unconfined compresive strength of lime-modifed clay is afeted by both bonding strengthening and water film weakening,and bonding strengthening is related to curing time,which shows an inceasing trend with the inerease of curing time.From the point of view of microstructure,the micro-particles and micro-pores of the clay became smaller and the particle bonding was enhanced after lime was added.Compared with the lime-modified clay with 20%water content,the amount of lime-modifed red clay aggregates with 23%water content increased and the lime reacted more fully with clay minerals.

关 键 词：黏土 弱膨胀土 石灰 含水率 

分 类 号：TU44[建筑科学—岩土工程]