干湿循环下钢渣微粉水泥改良膨胀土强度特性试验研究  

Experimental Study on Strength Characteristics of Expansive Soil Modified with Steel Slag Micropowder and Cement under Dry-wet Cycles

作　　者：吴燕开[1,2] 李丹丹 胡兴涛 韩天 于佳丽 史可健 王浩 曹玉鹏 WU Yan-kai;LI Dan-dan;HU Xing-tao;HAN Tian;YU Jia-li;SHI Ke-jian;WANG Hao;CAO Yu-peng(Key Laboratory of Disaster Prevention and Reduction of Civil Engineering in Shandong Province,Qingdao 266590,China;School of Civil Engineering and Architecture,Shandong University of Science and Technology,Qingdao 266590,China;Taian Boao Safety Evaluation Co.,Ltd.,Taian 271000,China;China Railway Construction Engineering Group Shandong Co.,Ltd.,Qingdao 266061,China;School of Traffic Engineering,Shandong University of Science and Technology,Qingdao 266590,China)

机构地区：[1]山东省土木工程防灾减灾重点实验室,青岛266590 [2]山东科技大学土木工程与建筑学院,青岛266590 [3]泰安博奥安全评价有限公司,泰安271000 [4]中铁建工集团山东有限公司,青岛266061 [5]山东科技大学交通工程学院,青岛266590

出　　处：《科学技术与工程》2020年第15期6211-6220,共10页Science Technology and Engineering

基　　金：国家自然科学基金青年基金(51608312);山东科技大学科研创新团队支持项目(2015KYDT104)。

摘　　要：膨胀土作为一种非饱和黏性土,因其吸水膨胀失水收缩的特性而成为一种具有危害性的地质土体,尤其在干湿气候交替变化的环境中,更会因其湿胀干缩产生变形导致工程事故的发生。通过使用钢渣粉作为新型固化剂,与水泥组合改良膨胀土,研究改良膨胀土在干湿循环条件下的强度特性变化规律。通过室内试验研究了纯膨胀土(Es)、水泥改良膨胀土(Es-C)、钢渣粉-水泥改良膨胀土(Es-SSP-C)和钢渣粉-水泥-NaOH改良膨胀土(Es-SSP-C-N)在不同养护龄期以及不同干湿循环次数作用下其无侧限抗压强度变化规律。试验结果表明:3种改良土体的强度都随养护龄期的增加而增大,并且在干湿循环作用下四种土体都有不同程度的强度损失,但在强度上总是呈现出Es-SSP-C-N>Es-C>Es-SSP-C>Es的规律,意味着在改良效果上Es-SSP-C-N更优于另外两种方案。Expansive soil,as an unsaturated cohesive soil,is a harmful geological soil due to its nature of bulging in wetness and shrinking in dryness.Especially in the environment of alternating wet and dry climate,it would cause engineering accidents because of its nature.To solve this problem,expansive soils were modified with steel slag powder and cement to improve the performance,and the mechanical variation was analyzed under dry-wet cycles.In laboratory,four differently formulated expansive soils were tested,i.e.,pure expansive soil(Es),cement modified(Es-C),steel slag powder-cement modified(Es-SSP-C),and steel slag powder-cement-NaOH modified(Es-SSP-C-N).Their variations in unconfined compressive strength were determined under different curing ages and dry-wet cycles.Results show that the strength of the three modified soils increase with the increase of curing age,and the four soils have different degrees of strength loss under dry-wet cycles,but the strength is always in an order of Es-SSP-C-N>Es-C>Es-SSP-C>Es,which means that Es-SSP-C-N is the best among them all.

关 键 词：干湿循环 改良膨胀土 应力-应变曲线 无侧限抗压强度 

分 类 号：TU443[建筑科学—岩土工程]