高寒盐碱地区隧道掺硅灰混凝土性能试验研究  

Experimental study on performance of tunnel concrete with silica fume in alpine saline-alkali area

作　　者：赵军[1] 杜浩 赵浩阳 ZHAO Jun;DU Hao;ZHAO Hao-yang(Department of Civil and Architecture Engineering,Anhui University of science and technology,Huainan 232001,China)

机构地区：[1]安徽理工大学土木建筑学院,安徽淮南232001

出　　处：《陕西理工大学学报（自然科学版）》2022年第4期23-30,共8页Journal of Shaanxi University of Technology:Natural Science Edition

基　　金：国家自然科学基金项目(51979268);中国博士后基金项目(2014M0502)。

摘　　要：我国西北高寒盐碱地区隧道常年受冻融及盐碱侵蚀影响,为研究盐碱成分不同和盐碱浓度不同的高寒盐碱地区掺硅灰混凝土结构的损伤情况,以及掺硅灰混凝土在高寒盐碱地区工程结构中的适用性,以质量分数5%、10%、15%的氯化钙溶液、硫酸钠溶液和水作为介质,开展冻融循环及盐碱侵蚀试验。通过对试验结果中质量损失、抗压强度、劈拉强度、动弹性模量的变化分析得出:(1)水灰比不变,硅灰掺量在0~15%时,随硅灰掺量增加混凝土塌落度减小,硅灰掺量5%~10%最优;(2)冻融及盐碱侵蚀下,混凝土试件的质量呈现先增加再减小趋势,混凝土结构出现蜂窝、孔洞、起壳等松散破坏;(3)硫酸钠对混凝土侵蚀力度最大、氯化钙次之、单一水最小;(4)当盐碱溶液的质量分数小于10%时,掺硅灰可有效提升结构的早中期强度,大于10%时则不能保证。The tunnels in the alpine saline-alkali area of northwest China are always affected by freeze-thaw and saline-alkali erosion.In order to study the damage of silica fume concrete structures in alpine saline-alkali areas with different saline-alkali components and saline-alkali concentrations,and the applicability of silica fume concrete in engineering structures in alpine saline-alkali areas,the study has used calcium chloride solution,sodium sulfate solution and water with mass fractions of 5%,10%and 15%as medium to carry out freeze-thaw cycles and saline-alkali erosion tests.Through the analysis of the changes of mass loss,compressive strength,splitting tensile strength and dynamic elastic modulus in the test results,it is concluded that:(1)When the water-cement ratio is constant and the silica fume content is 0~15%,the slump of concrete decreases with the increase of silica fume content,and the optimal silica fume content is 5%~10%;(2)Under freeze-thaw and saline-alkali erosion,the quality of concrete specimens increases first and then decreases,and loose damage such as honeycomb,hole and shelling occurs in concrete structures;(3)Sodium sulfate has the greatest erosion on concrete,followed by calcium chloride,and single water has the worst erosion;(4)When the mass fraction of saline-alkali solution is less than 10%,silica fume can effectively improve the early and middle strength of the structure,but it cannot be guaranteed when the mass fraction is greater than 10%.

关 键 词：冻融循环 盐碱侵蚀 抗压强度 质量损失 动弹性模量 

分 类 号：TU528.31[建筑科学—建筑技术科学]