摘要
为了探究青稞秸秆灰(HBSA)对氯氧镁水泥砂浆(MOCM)的抗盐冻耦合侵蚀性能影响,对不同HBSA掺量的MOCM进行盐冻耦合侵蚀试验。采用抗盐冻耦合侵蚀性能评价参数并结合表观形貌分析,反映了MOCM的损伤规律及劣化特征,进而确定了HBSA的最佳掺量。基于低场核磁共振技术(LF-NMR)分析了盐冻耦合侵蚀过程中MOCM的孔隙结构特征,结合热重(TG)分析和扫描电子显微镜(SEM)测试,表征了MOCM的微观结构组成,揭示了HBSA对MOCM抗盐冻侵蚀性能影响的内在原因。最后,采用Weibull分布函数对MOCM的抗盐冻侵蚀性能劣化规律进行可靠性分析。结果表明,HBSA掺量为10%时,MOCM表现出最佳的抗盐冻耦合侵蚀性能,与未掺HBSA时相比提高了19%。HBSA的掺入有效改善了MOCM的孔隙结构,显著减小了有害孔和多害孔的比例。当HBSA掺量为10%时,MOCM中生成了大量M-S-H凝胶,填充了大量的有害孔隙,增强了MOCM基体结构的密实性,从而提高了抗盐冻侵蚀性能。根据Weibull分布函数的可靠性分析结果,掺入10%HBSA的MOCM在盐冻耦合侵蚀环境下的可靠性明显高于未掺HBSA时。研究结果为氯氧镁水泥(MOC)在盐湖盐渍土地区的工程应用提供理论参考。
In order to investigate the effect of highland barley straw ash(HBSA)on the resistance to salt-frozen coupled erosion of magnesium chloroxylate cement mortar(MOCM),salt-frozen coupled erosion tests were carried out on MOCM with different HBSA dosages.The damage patterns and deterioration characteristics of MOCM were reflected by the evaluation parameters of resistance to salt-frozen coupled erosion and combined with the analysis of the apparent morphology,and then the optimal dosage of HBSA was determined.Based on the low-field nuclear magnetic resonance technique(LF-NMR),the pore structure characteristics of MOCM during the resistance to salt-frozen coupled erosion were analyzed.Combined with thermogravimetric analysis(TG)and scanning electron microscope test(SEM),the microstructural compositions of MOCM were characterized,which revealed the intrinsic reasons for the influence of HBSA on the resistance to salt-frozen erosion performance of MOCM.Finally,the reliability analysis of the deterioration law of resistance to freezing and erosion performance of MOCM was carried out by using the Weibull distribution function.The results showed that MOCM exhibited the best resistance to salt-frozen coupled erosion performance when the HBSA doping was 10%,which was increased by 19%compared with that without HBSA.The doping of HBSA effectively improved the pore structure of MOCM,and significantly reduced the proportion of harmful pores and multi-harmful pores.When the doping of HBSA was 10%,a large number of M-S-H gels were generated in the MOCM,which filled a large number of harmful pores and enhanced the denseness of the matrix structure of the MOCM,thus improving the resistance to salt-frozen coupled erosion.According to the reliability analysis results of the Weibull distribution function,the reliability of MOCM mixed with 10%HBSA in the salt-freezing coupled erosion environment was significantly higher than that without HBSA.The results of the study provide a theoretical reference for the engineering applications of magnesium oxychloride cement(MOC)in the saline soil areas of the salt lakes.
作者
欧阳浩
曹锋
郑明杰
乔宏霞
李双营
OUYANG Hao;CAO Feng;ZHENG Mingjie;QIAO Hongxia;LI Shuangying(School of Civil and Transportation Engineering,Qinghai Minzu University,Xining 810000,China;Shanghai Saiyang Architecture Tokyo Office,Tokyo 104-0033,Japan;School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China)
出处
《铁道科学与工程学报》
北大核心
2025年第4期1635-1646,共12页
Journal of Railway Science and Engineering
基金
教育部春晖计划自主合作研究基金资助项目(HZKY20220452)
国家自然科学基金资助项目(52178216)
青海省重点研发与转化计划(2022-QY-222)。
关键词
氯氧镁水泥
青稞秸秆灰
盐冻耦合侵蚀
孔隙特征
Weibull分布函数
magnesium oxychloride cement
highland barley straw ash
salt-frost coupled erosion
pore characterization
Weibull distribution function
