水泥-磨细矿渣固化滨海盐渍土强度及机理  

Strength and Mechanism of Stabilized Coastal Saline Soil by Cement and Fine Slag

作　　者：赵庆新[1] 才鸿伟 安赛 刘继中 ZHAO Qingxin;CAI Hongwei;AN Sai;LIU Jizhong(Key Laboratory of Green Construction and Intelligent Maintenance for Civil Engineering of Hebei Province, Yanshan University, Qinhuangdao 066004, China;College of Urban Construction, Hebei Normal University of Science & Technology, Qinhuangdao 066004, China)

机构地区：[1]燕山大学河北省土木工程绿色建造与智能运维重点实验室,河北秦皇岛066004 [2]河北科技师范学院城市建设学院,河北秦皇岛066004

出　　处：《建筑材料学报》2020年第3期625-630,共6页Journal of Building Materials

基　　金：国家自然科学基金资助项目(51578477);河北科技师范学院海洋学科专项(2018HY015)。

摘　　要：用水泥和磨细矿渣制作复合固化剂,来加固滨海盐渍土.测试滨海盐渍加固土(以下简称加固土)7、28、90d龄期的无侧限抗压强度,并结合加固土烧失量、固结物含量、X射线衍射(XRD)仪、热 重 差示扫描量热(TG-DSC)法和扫描电子显微镜(SEM)探究其加固机理.结果表明:水泥-磨细矿渣复合固化剂的加固效果明显优于单掺水泥或磨细矿渣,且当磨细矿渣掺量为0%~75%时,加固土7、 28d 无侧限抗压强度随磨细矿渣掺量增大而逐渐增强,最高可达6.0、10.0MPa;当磨细矿渣掺量为25%~100%时,90d龄期时加固土强度均达到11.5MPa以上,远高于单掺水泥加固土强度;加固土强度与其固结物含量呈正相关,而与其烧失量相关性不强.加固土28d龄期SEM照片显示,复合固化剂的水化产物与盐渍土结合较好,致密性明显优于单掺水泥或磨细矿渣;固结物是加固土强度的主要来源,其由固化剂水化产物及其黏结的土颗粒构成,受水化产物数量和团粒化作用共同影响.Cement and fine slag composite stabilizer were used to stabilize the coastal saline soil.The unconfined compressive strengths of 7,28,90d of stabilized soil were tested,and the stabilization mechanism was investigated in terms of the loss on ignition,the content of hardened materials,and the means of XRD,TG-DSC and SEM.The results shows that the stabilizing effect of cement and fine slag composite stabilizer is better than that of simply stabilizer,and when the content of fine slag is 0%-75%,with the increase of the amount of slag in the stabilizer,the 7,28d unconfined compressive strength of stabilized soil is gradually improved,which is up to 6.0,10.0MPa;when the content of fine slag is 25%-100%,the unconfined compressive strength of stabilized soil reaches 11.5MPa at 90d,much higher than that of cement alone;and the strength of the stabilized soil is positively related to the content of hardened materials,However,it is not closely related to the loss on ignition.The SEM image of specimen for 28d shows that the hydrates of composite stabilizer are well combined with the saline soil and the compactness of stabilized soil with composite stabilizer is much better than that for simply stabilizer.Hardened materials in stabilized soil is the main source of strength of stabilized soil,and it is composed of hydration products of the stabilizer and soil particles bonded by hydration products.The amount of hardened materials is affected by the amount of hydration products and agglomeration.

关 键 词：盐渍土 固化 强度 机理 微观结构 

分 类 号：TU526[建筑科学—建筑技术科学]