摘要
为了研究工程用水泥基复合材料(ECC)的抗拉及抗弯性能,开展了9组ECC的抗拉、抗弯试验,探讨了水胶比、粉煤灰掺量对ECC力学性能的定量影响规律,分析抗拉强度、极限拉应变、弹性模量、抗弯强度、弯曲韧性等参数的变化规律,并进行综合性能评估。结果表明:随着水胶比的增大,ECC的初裂抗拉强度和极限抗拉强度均呈现下降趋势,当水胶比大于0.35时,极限抗拉强度随粉煤灰掺量的增大逐渐减小;E5,E8试件极限拉应变超过4.5%,极限拉应变的变化规律与试件开裂模式相关性强。随着水胶比的增大,ECC的初裂抗弯强度和极限抗弯强度减小,极限挠度显著增大,涨幅最大可达229%;粉煤灰掺量取60%时,试件初始弯曲韧度比较高,峰前增韧效果较好;水胶比取0.35时,残余弯曲韧度比略高,峰后韧性较好。9组试件均满足多裂缝开裂机制的应力准则。基于雷达图评估,推荐E5(m水泥∶m粉煤灰∶m水∶m石英砂=0.40∶0.60∶0.35∶0.36,PVA纤维体积分数2%)为综合性能表现优异的组别。
To study the tensile and flexural properties of engineered cementitious composite(ECC),tensile and flexural tests were conducted on nine groups of ECC specimens.On this basis,the quantitative effects of water-binder ratio and fly ash content on the mechanical properties of ECC were explored.Subsequently,the variation patterns of parameters such as tensile strength,ultimate tensile strain,elastic modulus,flexural strength,and flexural toughness were analyzed,and a comprehensive assessment of its performance was conducted.The results demonstrate that as the water-binder ratio increases,both the initial tensile strength and ultimate tensile strength of ECC go downward.When the water-binder ratio exceeds 0.35,the ultimate tensile strength gradually decreases with the increase of fly ash content.The ultimate tensile strains of Groups E5 and E8 exceed 4.5%,and the variation in ultimate tensile strain is strongly correlated with the cracking mode of the specimens.With the increase of water-binder ratio,the initial crack bending strength and ultimate bending strength of ECC weaken,while the maximum deflection considerably grows,the maximum growth being up to 229%.When the fly ash content is 60%,the specimen presents a relatively high initial flexural toughness and a remarkable pre-peak toughening effect.With a water-to-binder ratio of 0.35,the residual bending toughness ratio is slightly higher,and the post-peak toughness is improved.All of the nine groups of specimens satisfy the stress criterion for a multi-crack cracking mechanism.Based on the radar chart evaluation,Group E5(with a cement∶fly ash∶water∶quartz sand ratio of 0.40∶0.60∶0.35∶0.36 and a PVA fiber volume fraction of 2%)is recommended as the group that boasts excellent overall performance.
作者
巩妮娜
柳文淑
蔡小宁
范向前
章鹏
耿方方
GONG Nina;LIU Wenshu;CAI Xiaoning;FAN Xiangqian;ZHANG Peng;GENG Fangfang(Institute of Civil Engineering and Intelligent Management,Nanjing Institute of Technology,Nanjing,Jiangsu 211167,China;School of Civil and Ocean Engineering,Jiangsu Ocean University,Lianyungang,Jiangsu 222005,China;Nanjing Hydraulic Research Institute,Nanjing,Jiangsu 210024,China;School of Architecture Engineering,Nanjing Institute of Technology,Nanjing,Jiangsu 211167,China)
出处
《采矿与安全工程学报》
北大核心
2025年第6期1434-1442,共9页
Journal of Mining & Safety Engineering
基金
国家自然科学基金青年基金项目(52101313,12202179)
国家自然科学基金项目(51878315,52171270,51879168)
国家自然科学基金委—河南省联合基金重点项目(U23A20672)
江苏省自然科学基金项目(BK20221400)
南京工程学院科研启动基金项目(YKJ202322)。
关键词
工程用水泥基复合材料
水胶比
粉煤灰掺量
抗拉性能
抗弯性能
engineered cementitious composite
water-binder ratio
fly ash content
tensile properties
flexural properties
