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
出处
《广西大学学报（自然科学版）》
CAS
北大核心
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)
关键词
混杂纤维混凝土
四点弯曲试验
韧性
增韧机理
hybrid fiber reinforced concrete
tbur-point bending test
toughness
toughening mech-anism
