钢锭铣削型纤维增强混凝土的弯曲性能及韧性评估  

Flexural Behavior and Toughness Evaluation of Milled-Cut Steel Fiber Reinforced Concrete

作　　者：刘诗琪 刘玉擎[1] 李永君 徐骁青 LIU Shiqi;LIU Yuqing;LI Yongjun;XU Xiaoqing(Department of Bridge Engineering,Tongji University,Shanghai 200092,China;Shanghai Municipal Engineering Design Institute(Group)Co.,Ltd.,Shanghai 200092,China)

机构地区：[1]同济大学桥梁工程系,上海200092 [2]上海市政工程设计研究总院(集团)有限公司,上海200092

出　　处：《结构工程师》2025年第2期74-82,F0004,共10页Structural Engineers

摘　　要：为探究钢锭铣削型钢纤维对普通混凝土受弯开裂行为和弯曲韧性的影响,对掺入不同钢纤维体积分数(0%、0.6%、1%、1.4%)的强度等级为C50的混凝土进行四点弯曲试验,分析钢锭铣削型钢纤维增强混凝土的弯曲行为、开裂形式及破坏机理,探究国内外规范中现有纤维混凝土弯曲韧性评价方法的适用性。研究结果表明,钢锭铣削型钢纤维增强混凝土的最大等效抗弯强度为普通混凝土的1.8倍;纤维体积掺量超过临界值1%后,材料表现出多缝开裂特性,增至1.4%后出现挠度硬化行为;JG/T 472—2015《钢纤维混凝土》规范中的方法适用于表征钢锭铣削型钢纤维增强混凝土弯曲韧性,纤维体积掺量的增加可以提高混凝土的弯曲变形能力,改善小挠度区间裂后弯曲韧性。To investigate the influence of milled-cut steel fiber(MSF)on the flexural behavior and toughness of plain concrete,four-point bending tests were conducted on C50 concrete matrixes with different volume fractions of steel fiber(0%,0.6%,1%,1.4%).The flexural behavior,cracking mode,and failure mechanisms of milled-cut steel fiber reinforced concrete(MSFRC)was analyzed.The evaluation methods for flexural toughness of fiber-reinforced concrete in domestic and international standards were studied to assess their applicability.The results indicate that the maximum equivalent flexural strength of the MSFRC is 1.8 times than that of plain concrete.Upon surpassing the critical fiber volume fraction of 1%,the material displays multiple cracking characteristics,with strain hardening behavior observed at an enhanced fraction of 1.4%.The method specified in JG/T 472—2015 steel fiber reinforced concrete is applicable for characterizing the flexural toughness of milled-cut steel fiber reinforced concrete.The increase in fiber volume fraction enhances the flexural deformation capacity of concrete and improves the post-cracking flexural toughness within the small deflection range.

关 键 词：纤维混凝土 钢纤维 钢锭铣削型 弯曲韧性 抗裂性能 

分 类 号：TU528[建筑科学—建筑技术科学]