玄武岩微筋对磷酸镁修补砂浆弯曲性能的增强增韧效应研究  

Study of Flexural Strengthening and Toughening Effect of Basalt Minibar on Magnesium Phosphate Cement Repair Mortar

作　　者：李伟[1,2] 谢剑[1,3] 佟成龙[4] LI Wei;XIE Jian;TONG Chenglong(School of Civil Engineering,Tianjin University/Key Laboratory of Coast Civil Structure Safety of the Ministry of Education,Tianjin University,Tianjin 300350,China;School of Civil Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China;Beijing Engineering Research Center of Existing Building Renovation(Tianjin Branch),Tianjin 300350,China;The 3rd Construction Co.,Ltd.,of China Construction 5th Engineering Bureau,Tianjin 300300,China)

机构地区：[1]天津大学建筑工程学院/天津大学滨海土木工程结构与安全教育部重点实验室,天津300350 [2]兰州交通大学土木工程学院,兰州730070 [3]北京市既有建筑改造工程技术研究中心(天津分中心),天津300350 [4]中建五局第三建设有限公司,天津300300

出　　处：《材料导报》2024年第17期32-40,共9页Materials Reports

基　　金：国家自然科学基金(52068043);甘肃省建设科技攻关项目(JKR2021-07);兰州市人才创新创业项目(2019-RC-78)。

摘　　要：为了探究玄武岩微筋(Basalt minibar)对磷酸镁修补砂浆(MPCRM)的增强增韧改性效果,通过四点弯曲试验分析纤维类型、纤维掺量、基体水胶比及养护条件对MPCRM弯拉强度和弯曲韧性的影响规律。试验结果表明:玄武岩微筋对MPCRM的弯曲增强增韧性能优越,且其增韧效果优于玄武岩单丝纤维;当玄武岩微筋掺量不低于1.0%(体积分数)时,MPCRM弯拉强度和弯曲韧性均随着玄武岩微筋掺量增加而提高;随着水胶比提高,玄武岩微筋增强MPCRM的弯曲韧性降低,弯拉强度先增加后减小,水胶比为0.18和体积掺量为1.5%的玄武岩微筋增强MPCRM的弯拉强度最大;掺入玄武岩微筋能够部分弥补低温养护MPCRM的受冻损伤。In order to study the strengthening and toughening modification of basalt minibar on magnesium phosphate cement repair mortar(MPCRM),the effects of different test parameters(fiber type,fiber volume fraction,water-binder ratio and curing conditions)on flexural strength and toughness of MPCRM were analyzed by four-point bending test.The results show that the basalt minibar has excellent flexural strengthening and toughening properties for MPCRM,and its toughening effect is better than that of traditional basalt monofilament fiber.Under the condition that the volume fraction of basalt minibar is not less than 1.0%,the flexural strength and toughness of MPCRM increase with the increase of volume fraction of basalt minibar.The flexural toughness of basalt minibar reinforced MPCRM decreases with the increase of water-binder ratio,while its flexural strength increases first and then decreases.The bending performance of basalt minibar reinforced MPCRM with water-binder ratio of 0.18 and the volume fraction of 1.5%is the best.The low temperature curing conditions cause the deterioration of the bending performance of MPCRM,the incorporation of basalt minibar can partially compensate for the frost damage of MPCRM.

关 键 词：磷酸镁修补砂浆(MPCRM) 玄武岩微筋 拔出功 弯曲韧性 低温养护 

分 类 号：U444[建筑科学—桥梁与隧道工程]