摘要
为探究掺入青稞秸秆灰(HBSA)对氯氧镁水泥(MOC)的耐久性能与孔隙结构的影响,采用HBSA来改善MOC的耐久性能,制备青稞秸秆灰-氯氧镁水泥复合材料。对不同HBSA掺量的氯氧镁水泥砂浆(MOCM)分别在盐湖卤水侵蚀、冻融循环侵蚀及盐冻耦合侵蚀条件下的耐久性能进行研究,采用相对质量评价参数、相对动弹性模量评价参数及相对抗压强度评价参数3种耐久性评价指标来反映MOCM的耐久性能劣化规律,并确定HBSA的最佳掺量。通过表观形貌分析及孔隙结构测试,揭示不同侵蚀环境下MOCM的耐久性损伤劣化程度及孔隙结构特征。结果表明:冻融循环侵蚀对MOCM造成的耐久性损伤程度比盐卤侵蚀及盐冻耦合侵蚀更严重,MOCM试件表面产生了更多的宏观裂缝。HBSA掺入能够显著改善MOCM的耐久性能。当HBSA掺量为10wt%时,MOCM在盐湖卤水侵蚀、冻融循环侵蚀及盐冻耦合侵蚀条件下的耐久性能分别比未掺HBSA时提高了21.24%、23.48%和18.91%。掺入10wt%HBSA的MOCM的开口孔隙率减小,比表面积增大,最可几孔径和平均孔径减小,细化了MOCM的孔隙结构,提高了耐久性能。
In order to explore the effect of highland barley straw ash(HBSA)on the durability and pore structure of magnesium oxychloride cement(MOC),HBSA was used to improve the durability of MOC,and highland barley straw ash–magnesium oxychloride cement composites were prepared.The durability of magnesium oxychloride cement mortar(MOCM)with different HBSA contents were studied under the conditions of salt lake brine erosion,freeze-thaw cycle erosion and salt–frozen coupling erosion.Three durability evaluation indexes:Relative mass evaluation parameters,relative dynamic elastic modulus evaluation parameters and relative compressive strength evaluation parameters were used to reflect the durability deterioration law of MOCM,and determine the optimal content of HBSA.Through the analysis of apparent morphology and pore structure test,the durability damage degree and pore structure characteristics of MOCM under different erosion conditions were revealed.The results show that the durability damage of MOCM caused by freeze-thaw cycle erosion is more serious than salt brine erosion and salt-frozen coupling erosion,and more macro cracks are produced on the surface of MOCM specimens.The addition of HBSA can significantly improve the durability of MOCM.When the content of HBSA is 10wt%,the durability of MOCM under salt lake brine erosion,freeze-thaw cycle erosion and salt–frozen coupling erosion is 21.24%,23.48%and 18.91%higher than that without HBSA,respectively.The opening porosity of MOCM added with 10wt%HBSA decreases,the specific surface area increases,and the most probable pore diameter and average pore diameter decrease,which refines the pore structure of MOCM and improves the durability.
作者
曹锋
乔宏霞
李双营
赵紫岩
舒修远
崔丽君
CAO Feng;QIAO Hongxia;LI Shuangying;ZHAO Ziyan;SHU Xiuyuan;CUI Lijun(School of Civil and Transportation Engineering,Qinghai Minzu University,Xining 810000,China;School of Civil Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Gansu Advanced Civil Engineering Materials Engineering Research Center,Lanzhou 730050,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2023年第5期2972-2987,共16页
Acta Materiae Compositae Sinica
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)。
