水泥-微硅粉改良膨胀土工程特性试验研究  

Experimental study on engineering properties of cement-microsilica fume improved expansive soil

作　　者：张玉国[1] 秦培森 郭泰 王瑞雪 杜晓玉 杨畅 ZHANG Yu-guo;QIN Pei-sen;GUO Tai;WANG Rui-xue;DU Xiao-yu;YANG Chang(School of Civil Engineering and Architecture,Zhongyuan University of Technology,Zhengzhou 450007,China)

机构地区：[1]中原工学院建筑工程学院,河南郑州450007

出　　处：《河南城建学院学报》2024年第2期1-6,42,共7页Journal of Henan University of Urban Construction

基　　金：国家自然科学基金(U1204511,51509274);河南省自然科学基金项目(222300420596);河南省高等学校重点科研项目(19A560027)。

摘　　要：为研究水泥和微硅粉复合改良膨胀土作为路基填筑材料的工程性质,以南阳市内乡县某路段膨胀土路基填料为研究对象,通过膨胀力试验、无荷膨胀率试验、无侧限抗压强度试验以及直剪试验,分析其在不同养护龄期下的膨胀特性和力学特性,结合SEM电镜扫描分析改良机理,并探讨了改良膨胀土力学特性变化与微观形貌之间的关系。结果表明:随着水泥、微硅粉的加入及养护龄期的增加,改良膨胀土的抗压强度及抗剪强度提高,膨胀性降低;采用水泥-微硅粉复合改良膨胀土的效果更优;综合考虑改良效果和经济性,改良剂的最优掺量为水泥7%、微硅粉10%。In order to study the engineering properties of cement and microsilica fume composite modified expansive soil as subgrade filling material,the expansive soil subgrade filler of a road section in Neixiang County,Nanyang City,was taken as the research object,and its expansive and mechanical properties under different curing ages were analyzed through expansion force test,unloaded expansion rate test,unconfined compressive strength test and direct shear test.The mechanism of the improved expansive soil was analyzed by SEM scanning test,and the relationship between the change of mechanical properties and the micro-morphology of the improved expansive soil was discussed.The test results show that with the addition of cement and microsilica fume and the increase in curing age,the compressive and shear strength of the soil is increased,and the expansion of the improved expansive soil gradually decreases.The effect of composite improvement using two materials is particularly significant.Taking into account the effect and economy,the compound is mixed with cement and The optimal dosages of microsilica powder are 7%and 10%respectively.

关 键 词：膨胀土改良 水泥-微硅粉 工程特性 微观结构 

分 类 号：TU443[建筑科学—岩土工程]