纤维组合对混杂纤维混凝土弯曲性能的影响  

Influence of fiber combination on flexural properties of hybrid fiber reinforced concrete

作　　者：何锐[1] 李永鹏[1] 陈拴发[1] 嵇绍华[2] 

机构地区：[1]长安大学交通铺面材料教育部工程研究中心,陕西西安710061 [2]长安大学公路学院,陕西西安710064

出　　处：《广西大学学报（自然科学版）》2013年第6期1306-1312,共7页Journal of Guangxi University（Natural Science Edition）

基　　金：国家"十二五"科技支撑计划项目(2011BAE27B04)

摘　　要：针对混凝土多相多组分的特点,采用纤维混杂技术手段对混凝土进行增强,通过混凝土梁四点弯曲试验分析了4种纤维组合对混凝土弯曲性能的影响。研究结果表明,混杂纤维对混凝土抗压强度的影响不大,而明显增大抗弯拉强度和极限挠度,两者最大值分别达10.5 MPa和3.0 mm;荷载—挠度曲线具备了变形硬化特性,部分试件还出现了多缝开裂现象,韧性指数I30约为理性弹塑性材料的1.7倍。混杂纤维的增韧机理,一方面不同纤维组合将有不同纤维破坏模式,其中纤维拨出破坏模式有利于纤维增韧,另一方面多尺度混杂可以从不同层次对混凝土开裂进行约束,最终提高混凝土的韧性。To investigate the characteristics of muhiphase and muhicomponent of concrete, the influ- ence of four fiber combinations on the flexural properties of concrete was analysed by a four-point bending test of concrete beams. The results show that the compressive strength of the hybrid fiber re- inforced concrete changed mildly, but the flexural strength and ultimate deflection increased signifi- cantly, up to 10. 5 MPa and 3.0 mm, respectively, and the load-deflection curve was provided with the strain hardening characteristics. The phenomenon of multiple cracking appeared in some speci- mens and the toughness index 130 increased by 70%. On the hybrid fiber toughening mechanism, one possibility is that different fiber combinations may lead to the difference of fiber failure mode in which the fiber pull-out benefits fiber reinforcement, and another possibility is that multi-scale hy- brid of fibers can constrain cracking of concrete from different levels, which improves the of concrete. toughness

关 键 词：混杂纤维混凝土 四点弯曲试验 韧性 增韧机理 

分 类 号：TU528.572[建筑科学—建筑技术科学]