聚丙烯塑钢纤维混凝土抗冻性与孔结构研究  

Study on frost resistance and pore structure of polypropylene plastic fiber concrete

作　　者：刘朋 王桂花 刘俊成 肖力光[2] LIU Peng;WANG Guihua;LIU Juncheng;XIAO Liguang(College of Civil Engineering,Baicheng Normal University,Baicheng 137000,China;College of Materials Science and Engineering,Jilin Jianzhu University,Changchun 130118,China)

机构地区：[1]白城师范学院土木工程学院,吉林白城137000 [2]吉林建筑大学材料科学与工程学院,吉林长春130118

出　　处：《混凝土》2024年第6期43-47,52,共6页Concrete

基　　金：吉林省教育厅科学技术研究项目(JJKH20230023KJ);“十三五”国家重点研发计划项目(2018YFD1101001);吉林省科技发展计划项目(YDZJ202302CXJD033);吉林省大学生创新创业训练计划项目(S202210206048)。

摘　　要：为解决吉林省西部地区混凝土建筑物和构筑物抗冻性不足的问题,研究聚丙烯塑钢纤维掺量为0 kg/m^(3)、3 kg/m^(3)、6 kg/m^(3)和9 kg/m^(3)的混凝土在0次、50次、100次、150次和200次冻融循环后抗压强度变化规律,利用低磁场核磁共振技术,研究T_(2)谱图面积、分布和孔结构,借助扫描电子显微镜分析冻融前后不同聚丙烯塑钢纤维掺量的混凝土微观孔结构的变化,最终探究出冻融环境下混凝土抗压强度与内部微观孔结构和孔分布之间的关系。结果表明:随着冻融循环次数的增加,不同聚丙烯塑钢纤维掺量的混凝土抗压强度有不同程度地下降;T_(2)谱图整体呈现向右移的趋势,a峰T_(2)谱图面积和占比逐渐减小,b峰和c峰T_(2)谱图面积和占比逐渐增大,且c峰占比的增大速度大于b峰;冻融过程中聚丙烯塑钢纤维混凝土抗压强度与其内部有害孔和多害孔所占比例呈负相关。总体而言,6 kg/m^(3)的聚丙烯塑钢纤维对提高混凝土抗冻性效果最佳,其内部有害孔和多害孔所占比例最少。In order to solve the problem of insufficient frost resistance of concrete buildings and structures in western Jilin Province,the variation law of compressive strength of concrete with the polypropylene plastic fiber content of 0 kg/m^(3)、3 kg/m^(3)、6 kg/m^(3) and 9 kg/m^(3) after 0、50、100、150 and 200 times freeze-thaw cycles is studied,and the area and distribution of T_(2) spectrum and pore structure were studied by using low magnetic field nuclear magnetic resonance technology.With the help of the scanning electron microscope,the changes of micro-pore structure of concrete with the different polypropylene plastic fiber content before and after freezing and thawing were analyzed,and finally the relationship between compressive strength of concrete and internal micro-pore structure and pore distribution under freezing and thawing environment was explored.The results showed that with the increase of freeze-thaw cycles,the compressive strength of concrete with the different contents of the polypropylene plastic fiber decreased to varying degrees.The overall T_(2) spectrogram showed the trend of moving to the right,with the area and proportion of T_(2) spectrogram of peak a decreasing gradually,while the area and proportion of T_(2) spectrogram of peak b and peak c increasing gradually,and the proportion of peak c increasing faster than that of peak b.The compressive strength of concrete reinforced by the polypropylene plastic fiber was negatively correlated with the proportion of harmful pores and multi-harmful pores in it during freezing and thawing.Generally speaking,the 6 kg/m^(3) polypropylene plastic fiber had the best effect on improving the frost resistance of concrete,and the proportion of harmful pores and multi-harmful pores in it was the least.

关 键 词：聚丙烯塑钢纤维 抗冻性 抗压强度 孔结构 

分 类 号：TU528.572[建筑科学—建筑技术科学]