摘要
仿岩溶碳酸氢钙(CFPK)改良碳酸盐渍土具有一定效果,但是存在碳酸氢钙分解速率慢、分解不完全等问题,导致改性效果不理想。为提高CFPK的利用率,以人工配制的碳酸盐渍土作为研究对象,采用土体中预掺入碳酸钙作为CFPK反应的晶核剂,通过物理、化学、力学、微观结构等试验方法,研究碳酸钙晶核剂对CFPK改良碳酸盐渍土效果的影响。试验结果表明,随着碳酸钙晶核剂掺量的增加,CFPK分解的速率越快,分解越彻底。碳酸钙晶核剂和CFPK联合改良后,土体易溶盐含量降低,抗湿化崩解性、无侧限抗压强度、抗剪强度大大提高。综合考虑碳酸钙晶核剂最优掺量为5%。碳酸钙晶核剂诱导CFPK分解,所形成的碳酸钙晶核剂和具有胶结作用的碳酸钙的整体,对土体有填充与固化的作用,同时可吸附土中的盐分,达到提高碳酸盐渍土工程性质的效果。
The Calcium Bicarbonate From Pseudo-Karstification(CFPK)has certain effects on improving carbonate soil,but there are problems such as slow decomposition rate and incomplete decomposition of calcium bicarbonate,which leads to unsatisfactory modification effect.In order to improve the utilization rate of CFPK,the artificially prepared carbonate soil was taken as the research object,and the calcium carbonate pre-mixed in the soil was used as the nucleating agent for the CFPK reaction.Through physical,chemical,mechanical,microstructure and other test methods,this paper analyzed the effects of calcium carbonate nucleating agent on the improvement of carbonate soil by CFPK.The test results show that with the increase of calcium carbonate nucleating agent,the faster the decomposition rate of CFPK is,the more thorough the decomposition is.After the carbonate soil is improved by calcium carbonate nucleating agent and CFPK,the content of soluble salt in the soil is reduced,the resistance to wetting and disintegration,the unconfined compressive strength and the shear strength are greatly improved.The optimum dosage of calcium carbonate nucleating agent is 5%.Calcium carbonate nucleating agent can induce the decomposition of CFPK to form calcium carbonate with cementation.Together with calcium carbonate nucleating agent,it can fill and solidify the soil,and absorb the salt in the soil,so as to improve the engineering performance of carbonated saline soil.
作者
周详朋
任冠洲
蔡东廷
樊恒辉
孟敏强
杨秀娟
ZHOU Xiangpeng;REN Guanzhou;CAI Dongting;FAN Henghui;MENG Minqiang;YANG Xiujuan(College of Water Resources and Architectural Engineering,Northwest Agriculture and Forestry University,Yangling,Shaanxi 712100,China;Institute of Geotechnical Engineering/Museum of Problematic Rock and Soil,Northwest A&F University,Yangling,Shaanxi 712100,China)
出处
《水利与建筑工程学报》
2023年第2期88-94,共7页
Journal of Water Resources and Architectural Engineering
基金
国家自然科学基金项目(52079116)。
关键词
碳酸盐渍土
晶核剂
碳酸钙
碳酸氢钙
改性机理
carbonated soil
nucleating agent
calcium carbonate
calcium bicarbonate
modification mechanism
