scholarly journals Strengthening of Reinforced Concrete Slab-Column Connections with Carbon Fiber Reinforced Polymer Laminates

2019 ◽  
Vol 10 (1) ◽  
pp. 265 ◽  
Author(s):  
Cheng-Chih Chen ◽  
Shun-Long Chen
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Concrete Slab ◽  
Fiber Reinforced Polymer ◽  
Punching Shear ◽  
Carbon Fiber Reinforced Polymer ◽  
Cfrp Laminates ◽  
Reinforced Polymer

This study presents the structural behavior and punching shear strength of the concrete slab-column connections strengthened with carbon fiber reinforced polymer (CFRP) laminates. The variables considered for the twelve specimens included the compressive strength of the concrete, the ratio of the tensile steel reinforcement, and the amount of the CFRP laminates. Square concrete slabs were simply supported along four edges. During the test, monotonically concentrated load was applied to the stub column located at the center of the slab. The punching shear strength, stiffness, and mode of failure were investigated. Test results demonstrated that increasing the compressive strength of concrete, ratio of the steel reinforcement, and amount of the CFRP laminates led to an increase in the punching shear strength of the slabs. Moreover, the CFRP laminates were effective in appreciably increasing the punching shear strength of the slab-column connections. An analytical approach was conducted to calculate the punching shear strength of the slab-column connections strengthened with CFRP laminates. Based on the theory of reinforced concrete members, the application of the CFRP laminates increased the flexural strength of the slab and resulted in an increase of the effective depth of the slab section. Consequently, the punching shear strength was increased. The results of the analytical calculation revealed that the analytical work accurately predicted the experimental punching shear strength.

Rehabilitation of Continuous Reinforced Concrete Beams in Shear by External Bonding of Carbon Fiber Reinforced Polymer Strips for Sustainable Construction

2016 ◽  
Vol 708 ◽  
pp. 49-58
Author(s):  
Abdul Aziz Abdul Samad ◽  
Noridah Mohamad ◽  
Noorwirdawati Ali ◽  
J. Jayaprakash ◽  
Priyan Mendis
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Structural Integrity ◽  
Failure Load ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Rc Beams ◽  
Shear Strengthening ◽  
Reinforced Polymer

To achieve sustainability in construction, the rehabilitation of existing concrete structures is vital in ensuring its structural integrity and longevity. Therefore, an experimental investigation on the shear strengthening of 2-span continuous reinforced concrete (RC) beams wrapped with carbon fiber reinforced polymer (CFRP) strips were conducted. The beam specimens were subjected to four point bending test and loaded incrementally until failure occurs. Different wrapping schemes and layers of CFRP strips were externally bonded within the shear span of the beams. The failure load, modes of failure, its crack patterns, deflection profile were recorded and presented for discussion. From observation, the experimental results indicated good improvement as the shear strengthened beams shows enhanced failure load and shear strength capacity. An improved stiffness and ductility behaviour was also observed compared to the control beam. Comparison with ACI 440 (2008) design provisions for shear strength shows that the prediction values underestimated its experimental results. This indicates that the enhanced shear performances of the 2-span continuous RC beams prove the reliability of CFRP as a strengthening material. Hence, the shear strengthening technique allows the rehabilitation process of existing structural members to improve its structural integrity, longevity and sustainability.

scholarly journals Punching Shear Strength of Reinforced Concrete Flat Plates with GFRP Vertical Grids

2021 ◽  
Vol 11 (6) ◽  
pp. 2736
Author(s):  
Min Sook Kim ◽  
Young Hak Lee
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Fiber Reinforced Polymer ◽  
Punching Shear ◽  
Test Results ◽  
Shear Reinforcement ◽  
Flat Plates ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Vertical Grids

In this study, the structural behavior of reinforced concrete flat plates shear reinforced with vertical grids made of a glass fiber reinforced polymer (GFRP) was experimentally evaluated. To examine the shear strength, experiments were performed on nine concrete slabs with different amounts and spacings of shear reinforcement. The test results indicated that the shear strength increased as the amount of shear reinforcement increased and as the spacing of the shear reinforcement decreased. The GFRP shear reinforcement changed the cracks and failure mode of the specimens from a brittle punching to flexure one. In addition, the experimental results are compared with a shear strength equation provided by different concrete design codes. This comparison demonstrates that all of the equations underestimate the shear strength of reinforced concrete flat plates shear reinforced with GFRP vertical grids. The shear strength of the equation by BS 8110 is able to calculate the punching shear strength reasonably for a concrete flat plate shear reinforced with GFRP vertical grids.

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