青稞秸秆灰对氯氧镁水泥砂浆粘结强度的影响  

Effect of Highland Barley Straw Ash on the Bonding Strength of Magnesium Oxychloride Cement Mortar

作　　者：舒修远 乔宏霞[1,2] 曹锋 崔丽君 SHU Xiuyuan;QIAO Hongxia;CAO Feng;CUI Lijun(School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;School of Civil and Tansportation Engineering,Qinghai Minzu University,Xining 810000,China)

机构地区：[1]兰州理工大学土木工程学院,兰州730050 [2]青海民族大学土木与交通工程学院,西宁810000

出　　处：《材料导报》2023年第23期84-89,共6页Materials Reports

基　　金：国家自然科学基金(51868044);青海省基础研究计划项目(2022-ZJ-921)。

摘　　要：本工作研究了经青稞秸秆灰(HBSA)改性的氯氧镁水泥砂浆(MOCM)作为普通混凝土(NC)的防护层,来抵御西部盐湖地区卤水侵蚀的过程,本工作以普通混凝土作为粘结基层,分别研究了MOCM中掺入HBSA、混凝土基层涂刷界面剂以及不同MOCM厚度等因素对其粘结强度的影响。通过粘结拉拔试验确定最优的设计参数,进一步分析了盐卤侵蚀环境下HBSA改性MOCM粘结强度的损伤劣化规律。采用微观测试技术分析了MOCM的物相组成、官能团结构、微观形貌特征,揭示了HBSA对MOCM粘结性能的影响机理。结果表明,厚度为18 mm、掺入HBSA且涂刷界面剂的MOCM粘结强度最高,抵抗盐卤侵蚀的能力也最强。HBSA中有较多的活性SiO_(2),活性SiO_(2)能够与MOCM的水化产物发生二次水化反应,生成水化硅酸镁(M-S-H)凝胶,填充MOCM内部孔隙,增强其密实性,提高其粘结强度。In order to study the process of using magnesium oxychloride cement mortar(MOCM)modified with highland barley straw ash(HBSA)as a protective layer for ordinary concrete(NC)to resist brine erosion in the western salt lake area,this work uses ordinary concrete as a bonding agent.For the base layer,the effects of factors such as incorporating HBSA into MOCM,applying interface agents on the concrete base layer,and different MOCM thicknesses on its bonding strength were studied.The influence of various factors on the bond strength of MOCM was studied through bond pull-out tests,the optimal design parameters were determined,and the damage and deterioration rules of the bond strength of HBSA-modified MOCM under salt brine erosion environment were further analyzed.The phase composition,functional group structure and micro-morphological characteristics of MOCM were analyzed by microscopic testing technology,and the mechanism of the influence of HBSA on the bonding properties of MOCM was revealed.The results show that the MOCM with a thickness of 18 mm,doped with HBSA and coated with an interfacial agent has the highest bond strength and the strongest resistance to salt brine erosion.There are more active SiO_(2) in HBSA,which can undergo secondary hydration reaction with the hydration product of MOCM to generate hydrated magnesium silicate(M-S-H)gel,which fills the internal pores of MOCM,enhances compactness and improves bond strength.

关 键 词：氯氧镁水泥砂浆 活性混合材料 青稞秸秆灰 粘结性能 微观结构 影响机理 

分 类 号：TU526[建筑科学—建筑技术科学]