scholarly journals Numerical Modeling of Earthquake-Damaged Circular Bridge Columns Repaired Using Combination of Near-Surface-Mounted BFRP Bars with External BFRP Sheets Jacketing

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 258 ◽  
Author(s):  
Xing-Gui Zeng ◽  
Shao-Fei Jiang ◽  
Xin-Cheng Xu ◽  
Hai-Sheng Huang
Keyword(s):  
Numerical Modeling ◽  
Numerical Models ◽  
Basalt Fiber ◽  
Fiber Reinforced Polymer ◽  
Experimental Program ◽  
Near Surface ◽  
Reinforced Polymer ◽  
Near Surface Mounted ◽  
Damage Accumulation Model ◽  
Good Agreement

This paper reports the numerical simulation of earthquake-damaged circular columns repaired with the combination of near-surface-mounted (NSM) basalt fiber reinforced polymer (BFRP) bars with external BFRP sheets jacketing at quasi-static loading. The numerical modeling was carried out with the nonlinear OpenSees software platform by using the BeamWithHinges element. In the simulations, the effect of the previous earthquake damage on the behavior of the repaired columns was taken into account, and a simple and effective material damage-accumulation model is proposed to modify the constitutive of materials in the unrepaired regions of the repaired columns. The developed numerical models were validated by comparing their quasi-static findings with those obtained from a previous experimental program, and a good agreement can be observed. Furthermore, the efficiency of the repair technique used in tests is evaluated via the developed numerical model.

scholarly journals An Anchorage Technique for Shear Strengthening of RC T-Beams Using NSM-BFRP Bars and BFRP Sheet

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
Hesham M. Diab ◽  
Ahmed M. Sayed
Keyword(s):  
Reinforced Concrete ◽  
Basalt Fiber ◽  
Shear Capacity ◽  
Fiber Reinforced Polymer ◽  
Experimental Program ◽  
Shear Strengthening ◽  
Near Surface ◽  
Reinforced Polymer ◽  
Anchorage System ◽  
Near Surface Mounted

Abstract This study presents a detailed experimental program for reinforced concrete T-beams strengthened in shear with near-surface mounted (NSM) basalt fiber-reinforced polymer (BFRP) bars. This paper aims to introduce and evaluate a nonmechanical anchorage technique for shear strengthening using NSM-BFRP bars. T-beams were strengthened using manually manufactured closed or U-shaped hybrid BFRP stirrups (BFRP bars and BFRP sheets). The experimental program was developed to study the effects of these anchorage techniques. The results showed that the shear capacity increased by 8%–46% for beams strengthened with NSM-BFRP bars without anchorage. However, the presence of the proposed anchorage system increased the shear capacity of the strengthened beams by 39.6%–81.6%. Moreover, the maximum strains induced in the BFRP bars ranged from 27 to 59% of their ultimate strains according to the spacing between the NSM and the presence of the anchorage. The proposed anchorage technique prevented the premature debonding of the NSM-BFRP bars.

scholarly journals Numerical Analysis of the Flexural Response of Rc Beams Strengthened with NSM-CFRP

2018 ◽  
Vol 28 (3) ◽  
pp. 90-102
Author(s):  
Ahmed Khene ◽  
Habib Abdelhak Mesbah ◽  
Nasr-Eddine Chikh
Keyword(s):  
Parametric Study ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Near Surface ◽  
Flexural Response ◽  
Reinforced Polymer ◽  
Near Surface Mounted ◽  
Concrete Coating ◽  
A New Technique ◽  
Nsm Technique

Abstract In this study, we have chosen to use a new technique of reinforcement with composite materials, namely the near surface mounted technique (NSM). The NSM technique consists in inserting strips of carbon fiber reinforced polymer (CFRP) laminate into slits made beforehand at the level of the concrete coating of the elements to be reinforced. A numerical investigation was conducted on rectangular reinforced concrete beams reinforced with NSM-CFRP using the ATENA finite element code. A parametric study was also carried out in this research. The numerical results were compared with the experimental results of the beams tested by other researchers with the same reinforcement configurations. Overall, numerical behavior laws are rather well-suited to those obtained experimentally and the parametric study has also yielded interesting results.

scholarly journals Degradation of basalt fiber–reinforced polymer bars in seawater and sea sand concrete environment

2020 ◽  
Vol 12 (3) ◽  
pp. 168781402091288
Author(s):  
Suraksha Sharma ◽  
Daxu Zhang ◽  
Qi Zhao
Keyword(s):  
Numerical Models ◽  
Basalt Fiber ◽  
Fiber Reinforced Polymer ◽  
Fickian Diffusion ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Exposure Temperature ◽  
Sea Sand ◽  
Concrete Solution ◽  
Basalt Fiber Reinforced Polymer

Although numerous experimental and analytical investigations on the environmental effects on basalt fiber–reinforced polymer bars were carried out, degradation of the basalt fiber–reinforced polymer bar in seawater and sea sand concrete environment has been insufficiently analyzed. This work presents two distinct numerical approaches, degradation rate–based approach and diffusion-based approach, to investigate the durability of basalt fiber–reinforced polymer bars in seawater and sea sand concrete solution subjected to various temperatures (32°C, 40°C, 48°C, and 55°C). The degradation of the material was quantified using a simplified two-dimensional model of a homogenized basalt fiber–reinforced polymer bar in COMSOL Multiphysics software. Fickian diffusion provides basis for modeling diffusion-based approach. The findings from both the approaches suggested that the basalt fiber–reinforced polymer bar becomes more susceptible to degradation as the exposure temperature increases and results in greater geometrical deformities. The comparisons of experimental data, analytical solutions, and numerical results showcase that the present numerical models can predict the degradation of a basalt fiber–reinforced polymer bar in a seawater and sea sand concrete environment.

scholarly journals Characterization and Simulation of the Bond Response of NSM FRP Reinforcement in Concrete

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1770 ◽  
Author(s):  
Javier Gómez ◽  
Lluís Torres ◽  
Cristina Barris
Keyword(s):  
Load Capacity ◽  
Numerical Procedure ◽  
Fiber Reinforced Polymer ◽  
Near Surface ◽  
Bond Slip ◽  
Pull Out ◽  
Reinforced Polymer ◽  
Frp Reinforcement ◽  
Near Surface Mounted ◽  
Shear Stress And Strain

The near-surface mounted (NSM) technique with fiber reinforced polymer (FRP) reinforcement as strengthening system for concrete structures has been broadly studied during the last years. The efficiency of the NSM FRP-to-concrete joint highly depends on the bond between both materials, which is characterized by a local bond–slip law. This paper studies the effect of the shape of the local bond–slip law and its parameters on the global response of the NSM FRP joint in terms of load capacity, effective bond length, slip, shear stress, and strain distribution along the bonded length, which are essential parameters on the strengthening design. A numerical procedure based on the finite difference method to solve the governing equations of the FRP-to-concrete joint is developed. Pull-out single shear specimens are tested in order to experimentally validate the numerical results. Finally, a parametric study is performed. The effect of the bond–shear strength slip at the bond strength, maximum slip, and friction branch on the parameters previously described is presented and discussed.

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