聚丙烯纤维轻质高强混凝土动态力学特性研究  

Study on dynamic mechanical properties of polypropylene fiber lightweight high strength concrete

作　　者：李锐[1] 王飞 张凯宏 LI Rui;WANG Fei;ZHANG Kaihong(Intelligent Construction College,Neijiang Vocational and Technical College,Neijiang 641000,China;School of Hydropower,Sichuan University,Chengdu 610065,China;Key Laboratory of Traffic Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]内江职业技术学院智能建造学院,四川内江641000 [2]四川大学水电学院,四川成都610065 [3]西南交通大学交通隧道工程教育部重点实验室,四川成都610031

出　　处：《实验技术与管理》2023年第2期115-120,139,共7页Experimental Technology and Management

基　　金：国家自然科学基金项目(52078032)。

摘　　要：基于试验研究不同应变率下聚丙烯纤维轻质高强混凝土力学特性。采用电液伺服压力机及直径为74mm的分离式霍普金森压杆试验装置(SHPB)对不同纤维掺量(0%、0.05%、0.1%、0.2%、0.3%)的聚丙烯纤维轻质高强混凝土开展不同应变率下的单轴压缩试验,分析应变率及纤维掺量对试件力学性能的影响。结果表明:随着纤维掺量的增大,试件峰值应力均呈先增大后减小的趋势,纤维掺量在0.1%时试件峰值应力达到最大值;0.6 MPa气压下相较于未掺纤维试件,纤维掺量为0.05%、0.1%、0.2%、0.3%时其韧性增幅分别为57.04%、77.78%、65.19%、46.67%,纤维的掺入增强了试件的韧性,随着纤维掺量的增多试件韧性整体呈先增大后减小的趋势;试件应变率与DIF间呈线性正相关,随着纤维掺量的增多试件应变率敏感性先增大后减小,纤维掺量在0.1%时试件的应变率效应敏感性最强;试件入射能、耗散能与应变率间呈线性正相关,0.6 MPa气压作用下相较于纤维掺量为0%的试件,纤维掺量为0.05%、0.1%、0.2%、0.3%时其破碎耗能密度增幅分别为9.05%、11.52%、15.23%、15.64%,掺入适量的聚丙烯纤维能够显著提高试件的耗能效果,但过量的纤维对试件耗能作用提升不再明显。The mechanical properties of polypropylene fiber lightweight high strength concrete under different strain rates are studied based on experiments.The uniaxial compression tests of polypropylene fiber lightweight high-strength concrete with different fiber content(0%,0.05%,0.1%,0.2% and 0.3%)are carried out by using an electro-hydraulic servo press and a 74 mm diameter split Hopkinson compression bar test device(SHPB).The effects of strain rate and fiber content on the mechanical properties of the specimens are analyzed.The results show that with the increase of fiber content,the peak stress of the specimen increases first and then decreases.When the fiber content is 0.1%,the peak stress of the specimen reaches the maximum value.Under the pressure of 0.6 MPa,compared with the specimens without fiber,the toughness increases of the specimens with 0.05%,0.1%,0.2% and 0.3% fiber content are 57.04%,77.78%,65.19% and 46.67% respectively.The toughness of the specimens is enhanced by the incorporation of fiber.With the increase of fiber content,the toughness of the specimen increases first and then decreases.There is a linear positive correlation between strain rate and DIF.With the increase of fiber content,the strain rate sensitivity of the specimen increases first and then decreases.When the fiber content is 0.1%,the strain rate sensitivity of the specimen is the strongest.There is a linear positive correlation between the incident energy,dissipated energy and strain rate of the specimen.Under the pressure of 0.6 MPa,when the fiber content is 0.05%,0.1%,0.2% and 0.3%,the increase of crushing energy consumption density is 9.05%,11.52%,15.23% and 15.64% respectively compared with the specimen with 0% fiber content.Adding proper amount of polypropylene fiber can significantly improve the energy consumption effect of the specimen,but the energy consumption effect of excessive fiber is no longer obvious.

关 键 词：聚丙烯纤维 应变率 轻质高强混凝土 峰值应力 耗能密度 

分 类 号：TU528[建筑科学—建筑技术科学]