Shear Behavior of Circular Concrete Members Reinforced with GFRP Bars and Spirals at Shear Span-to-Depth Ratios between 1.5 and 3.0
Shear Behavior of Circular Concrete Members Reinforced with GFRP Bars and Spirals at Shear Span-to-Depth Ratios between 1.5 and 3.0
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DOI：
10.1061/(asce)cc.1943-5614.0000707
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发表时间：
2016-12-01
影响因子：
4.6
通讯作者：
Benmokrane, Brahim
中科院分区：
文献类型：
--
作者：
Ali, Ahmed H.;Mohamed, Hamdy M.;Benmokrane, Brahim
在过去的十年里，纤维增强聚合物(FRPS)加固的矩形截面混凝土构件的抗剪强度受到了相当大的关注。然而，在剪切荷载作用下，似乎还没有关于FRP加固圆形混凝土构件的研究。本文介绍了六个玻璃钢(GFRP)筋和螺旋筋加固的圆形混凝土试件的抗剪强度和性能试验结果。这些试件长3000 mm，直径500 mm，进行了四点弯曲试验。试验参数包括剪跨深比(a/d)从1.5到3.0，以及不同螺旋间距(100、150和200 mm)和螺旋直径(13和15 mm)的GFRP螺旋配筋率。按设计，a/d>；2.5的试件由于GFRP螺旋断裂或弯剪破坏而发生剪切破坏，a/d<；2.5的试件由于压杆压碎和螺旋断裂相结合而破坏。将试验结果与现行规范和设计准则中的截面模型、压杆模型以及基于修正压力场理论的现有分析方法进行了比较。比较表明，FRP筋混凝土圆形截面构件的抗剪承载力可按矩形截面抗剪设计规定在不同的保守度下确定。(C)2016年美国土木工程师学会。
In the last decade, the shear strength of concrete members with rectangular cross sections reinforced with fiber-reinforced polymers (FRPs) has received considerable attention. Yet no research seems to have investigated circular concrete members reinforced with FRP reinforcement under shear loads. This paper presents the results of an investigation of the shear strength and behavior of six circular concrete specimens reinforced with glass-FRP (GFRP) bars and spirals. The specimens, which measured 3,000 mm in length by 500 mm in diameter, were tested under four-point bending. The test parameters included the shear span-to-depth ratio (a/d) ranging from 1.5 to 3.0 and the GFRP spiral reinforcement ratio with different spiral spacings (100, 150, and 200 mm) and spiral diameters (13 and 15 mm). As designed, the specimens failed in shear due to GFRP spiral rupture or flexural-shear failure for the specimens with a/d > 2.5 and strut crushing combined with spiral rupture for the specimens with a/d < 2.5. The experimental results were compared to the current sectional models and the strut-and-tie model in codes and design guidelines as well as to the available analytical approach, which is based on the modified compression field theory. The comparison indicates that the shear capacity of FRP-reinforced concrete members with circular cross sections may be determined with the shear design provisions developed for rectangular sections within a variable degree of conservativeness. (C) 2016 American Society of Civil Engineers.