Tests on reinforced-concrete-filled, fiber-reinforced-polymer circular tubes of different shear spans

2007 ◽  
Vol 34 (3) ◽  
pp. 311-322 ◽  
Author(s):  
Amir Fam ◽  
Britton Cole
Keyword(s):  
Shear Strength ◽  
Shear Failure ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced Polymer ◽  
Concrete Core ◽  
Strut And Tie ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Strut And Tie Model

This study examines the shear behavior of concrete-filled glass-fiber-reinforced-polymer (GFRP) tubes (CFFTs) reinforced with either steel or fiber-reinforced-polymer (FRP) longitudinal rebar. To evaluate the contribution of the GFRP tubes, control specimens with and without steel spirals, instead of the tubes, were also tested. Shear span-to-depth ratios (a/D) of 1 and 2 were considered in 14 three-point bending tests. CFFT specimens with a/D = 1 failed in shear by diagonal tension failure of the concrete core and tube, whereas those with a/D = 2 failed mostly in flexure. Control specimens failed in shear at both a/D = 1 and a/D = 2. The shear strength of CFFT beams was substantially higher than that of control specimens but was dependent on rebar type and size. Some slip occurred between the concrete core and both the GFRP tube and the rebar. It is concluded that shear failure may occur in reinforced CFFTs at a/D ≤ 2. Despite the shear failure of steel-reinforced CFFTs at a/D = 1, the measured moments at failure were only 9% lower than their respective ultimate flexural strengths. A simplified strut-and-tie model was developed, and it showed reasonable agreement with experimental results.Key words: concrete-filled glass-fiber-reinforced-polymer tube (CFFT), concrete-filled, fiber-reinforced polymer (FRP), rebar, shear span, shear strength, tube, strut-and-tie model.

A comparative study of the thermophysical and mechanical properties of the glass fiber reinforced polymer bars with different cure ratios

2018 ◽  
Vol 52 (29) ◽  
pp. 4105-4116 ◽  
Author(s):  
Claude Nazair ◽  
Brahim Benmokrane ◽  
Marc-Antoine Loranger ◽  
Mathieu Robert ◽  
Allan Manalo
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Glass Fiber ◽  
Interlaminar Shear Strength ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced Polymer ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Interlaminar Shear

Cure ratio is a key property for the acceptance and use of glass fiber reinforced polymer bars in civil engineering infrastructure. Yet, there have been no reported studies investigating the effect of cure ratio on the physical, thermal, and mechanical properties of the fiber reinforced polymer bars. This paper presents an interlaboratory test program involving four laboratories to evaluate the cure ratio and glass transition temperature of glass fiber reinforced polymer bars from different production lots. The effect of cure ratio on the physical, mechanical, and microstructure of the glass fiber reinforced polymer bars was also evaluated. The results of this study show that the cure ratio significantly affected the glass transition temperature ( Tg) of the glass fiber reinforced polymer bars tested. The results also show that interlaminar shear strength of the glass fiber reinforced polymer bars was affected by the cure ratio but not the physical and tensile properties, microstructure, or chemical composition. The fully cured glass fiber reinforced polymer bars had interlaminar shear strength up to 8% higher than the partially cured bars. Nonetheless, the glass fiber reinforced polymer bars with a cure ratio of only 96% still had properties well above the minimum prescribed physical and mechanical properties for the reinforcing materials in concrete structures.

scholarly journals Remediation of Punching Shear Failure Using Glass Fiber Reinforced Polymer (GFRP) Rods

Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2369
Author(s):  
Ekkachai Yooprasertchai ◽  
Ratchanon Dithaem ◽  
Titi Arnamwong ◽  
Raktipong Sahamitmongkol ◽  
Jira Jadekittichoke ◽  
...  
Keyword(s):  
Glass Fiber ◽  
Shear Failure ◽  
Peak Load ◽  
Fiber Reinforced Polymer ◽  
Punching Shear ◽  
Deformation Capacity ◽  
Fiber Reinforced ◽  
Glass Fiber Reinforced Polymer ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced

The results of an experimental program on shear-strengthening of flat slabs using Glass Fiber Reinforced Polymer (GFRP) rods are presented. A total of seven specimens were tested under an upward concentric monotonic loading until failure. One specimen served as a control and was tested without any modification. The remaining six specimens were strengthened with post-installed GFRP rods in single (SG), double (DB), and radial (RD) patterns within shear critical parameters around the centric column. The results of this experimental study suggest that GFRP rods are capable of enhancing both the peak load and deformation capacity. Furthermore, brittle failure associated with punching shear failure was successfully avoided by all strengthening patterns. Of all of the patterns, the RD pattern resulted in maximum peak load increase and corresponding deformation capacity while the lowest bound was created by the SG pattern. The results suggested that SG, DB and RD patterns enhanced ultimate loads up to 9.1, 11.3 and 15.7% while corresponding deflections increased up to 109, 136 and 154%. Strain measurement on flexural reinforcement suggested that all strengthened specimens were able to withstand higher longitudinal strains than yield. It was further shown that reducing the spacing between the GFRP rods efficiently enhanced peak loads, nevertheless, neither this change was proportional, nor did it result in an enhanced energy dissipation capacity. In the end, recommendations of American Concrete Institute (ACI) for the shear strength of two-way systems were modified to incorporate the contributions from GFRP rods. The results indicate that the proposed analytical approach provides an excellent match with the experimental results.

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