scholarly journals Durability of RC Beams Strengthened Using GFRP-Sheet due to Fatigue Loads

2019 ◽  
Vol 280 ◽  
pp. 04012
Author(s):  
Tata Arbain ◽  
Raffel Anthonius Frederik ◽  
Ihsan Muhammad ◽  
Djamaluddin Rudy
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Maximum Load ◽  
Reinforced Concrete Beams ◽  
Glass Fiber Reinforced ◽  
Secondary Failure ◽  
Fatigue Loads ◽  
Monotonic Loads ◽  
Comparative Results ◽  
Reinforcement Bar

This paper presented the results of an experimental study of the behaviour of flexural beams strengthened with the glass fiber reinforced polymer (GFRP-S). This research was carried out to determine the effect of fatigue loads on the flexural capacity of reinforced concrete beams. The specimens were rectangular with a dimension of 150 mm in width, 200 mm in height, and 3300 mm in length. Four distinct conditions had been applied to this experiment. For the initial condition, two beams were tested under monotonic loads (maximum load control) as a control beam (BN). Sinusoidal fatigue loads were applied to four specimens from 4 kN to 24 kN (BF). Our comparative results of the experiment had presented that the normal beams (BN) failed after 800,000 loads cycle, while, the reinforced beams with GFRP (BF) failed after 1,231,860 loads cycle. Based on our results, it can be stated generally that fatigue life of the reinforcement beams (BF) could increase to more than 100% compared to that of the normal beams (BN). The failure of the beams is probably caused by fatigue of the reinforcement bar and debonding of the GFRP-S, both are secondary failure mechanism of reinforced concrete beams.

Numerical Analysis of Reinforced Concrete Beam Strengthened with CFRP or GFRP Laminates

2016 ◽  
Vol 707 ◽  
pp. 51-59 ◽  
Author(s):  
Osama Ahmed Mohamed ◽  
Rania Khattab
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beam ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Reinforced Concrete Beam ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced

The behaviour of reinforced concrete beam strengthened with Carbon Fiber Reinforced Polymer (CFRP) and Glass fiber reinforced polymer GFRP laminates was investigated using finite element models and the results are presented in this paper. The numerical investigation assessed the effect of the configuration of FRP strengthening laminates on the behaviour of concrete beams. The load-deflection behaviour, and ultimate load of strengthened beam were compared to those of un-strengthened concrete beams. It was shown that using U-shaped FRP sheets increased the ultimate load. The stiffness of the strengthed beam also increased after first yielding of steel reinforcing bars. At was also observed that strengthening beams with FRP laminates to one-fourth of the beam span, modifies the failure of the beam from shear-controlled near the end of the unstrengthened beam, to flexure-controlled near mid-span. CFRP produced better results compared GFRP in terms of the ability to enhance the behavior of strengthenened reinforced concrete beams.

scholarly journals Limiting Reinforcement Ratios for Hybrid GFRP/Steel Reinforced Concrete Beams

2021 ◽  
Vol 11 (1) ◽  
pp. 01-11
Author(s):  
Duy Phan Nguyen ◽  
Viet Quoc Dang
Keyword(s):  
Experimental Data ◽  
Reinforced Concrete ◽  
Concrete Beams ◽  
Steel Reinforcement ◽  
Reinforcement Ratio ◽  
Reinforced Concrete Beams ◽  
Equilibrium Equations ◽  
Steel Reinforced Concrete ◽  
Glass Fiber Reinforced ◽  
Load Carrying

In this work, a theoretical approach is proposed for estimating the minimum and maximum reinforcement ratios for hybrid glass fiber reinforced polymer (GFRP)/steel-reinforced concrete beams to prevent sudden and brittle failure as well as the compression failure of concrete before the tension failure of reinforcements. Equilibrium equations were used to develop a method for determining the minimum hybrid GFRP/steel reinforcement ratio. A method for determining the maximum hybrid GFRP/steel reinforcement ratio was also developed based on the equilibrium of forces of the balanced failure mode. For estimating the load-carrying capacity of concrete beams reinforced with hybrid GFRP/steel, less than the minimum and more than the maximum reinforcement ratio is recommended. Comparisons between the proposed expressions, experimental data, and available test results in the literature shows good agreement between the theoretical and experimental data, with a maximum discrepancy of 7%.

scholarly journals GFRP-sheet strengthened RC beams after seawater immersion under monotonic and fatigue loads

2019 ◽  
Vol 276 ◽  
pp. 01029 ◽  
Author(s):  
Arbain Tata ◽  
Anthonius Frederik Raffel ◽  
Muhammad Ihsan ◽  
Rudy Djamaluddin
Keyword(s):  
Concrete Beams ◽  
Sea Water ◽  
Water Immersion ◽  
Reinforced Concrete Beams ◽  
Glass Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Fatigue Loads ◽  
Monotonic Loads ◽  
Flexural Beam ◽  
Gfrp Reinforcement

This study aims to analyse glass fibre reinforced polymer (GFRP) reinforcement on reinforced concrete beams under fatigue and monotonic loads influenced by sea water. The research was conducted in the laboratory on flexural concrete beams with the quality of f´c= 25 MPa. One normal concrete flexural beam (BN) with repetitive load was without seawater and no reinforcement. One flexural beam was without sea water immersion but with GFRP-reinforcement. Another flexural beam reinforced by GFRP sheets is immersed in a pond containing seawater with time variations up to 12 months. The test was performed with a fatigue load of 1.25 Hz frequency to failure. The results showed an increase in capacity due to 58.3% for GFRP-reinforcement. There is a decrease in the capacity of GFRP sheet influenced by seawater immersion. The same trend with the decrease in ductility occurred in the flexural beam to 14% due to seawater immersion. Maximum beam failure repetition occurred at 1,230,000 cycles on beam with reinforcement (BF). The failure occurring in the flexural beam was preceded by the failure of the attachment between the concrete and the GFRP sheet at the load centre (mid of span) slowly to the support until failure (debonding) initialized. The GFRP-S bonding capacity to the concrete skin has decreased in 12 months by 15%. Therefore, there is a significant effect of decreasing strength due to fatigue loads and seawater immersion.

scholarly journals Analytical Study of Reinforced Concrete Beams Tested under Quasi-Static and Impact Loadings

2019 ◽  
Vol 9 (14) ◽  
pp. 2838 ◽  
Author(s):  
Sayed Mohamad Soleimani ◽  
Sajjad Sayyar Roudsari
Keyword(s):  
Reinforced Concrete ◽  
Glass Fiber ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced Polymers ◽  
Drop Height ◽  
Fiber Reinforced ◽  
Reinforced Polymers ◽  
Glass Fiber Reinforced Polymers ◽  
Glass Fiber Reinforced

During dynamic events (such as impact forces), structures fail to absorb the incoming energy and catastrophic collapse may occur. Impact and quasi-static tests were carried out on reinforced concrete beams with and without externally bounded sprayed and fabric glass fiber-reinforced polymers. For impact loading, a fully instrumented drop-weight impact machine with a capacity of 14.5 kJ was used. The drop height and loading rate were varied. The load-carrying capacity of reinforced concrete beams under impact loading was obtained using instrumented anvil supports (by summing the support reactions). In quasi-static loading conditions, the beams were tested in three-point loading using a Baldwin Universal Testing Machine. ABAQUS FEA software was used to model some of the tested reinforced concrete beams. It was shown that the stiffness of reinforced concrete beams decreases with increasing drop height. It was also shown that applying sprayed glass fiber-reinforced polymers (with and without mechanical stiffeners) and fabric glass fiber-reinforced polymers on the surface of reinforced concrete beams increased the stiffness. Results obtained from the software analyses were in good agreement with the laboratory test results.

scholarly journals Flexural Behavior of Reinforced Concrete Beams Retrofitted with Modularized Steel Plates

2021 ◽  
Vol 11 (5) ◽  
pp. 2348
Author(s):  
Min Sook Kim ◽  
Young Hak Lee
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Load Capacity ◽  
Maximum Load ◽  
Reinforced Concrete Beams ◽  
Steel Plates ◽  
Flexural Behavior ◽  
Element Analysis ◽  
Flexural Performance ◽  
Structural Capacity

Many structural retrofitting methods tend to only focus on how to improve the strength and ductility of structural members. It is necessary for developing retrofitting strategy to consider not only upgrading the capacity but also achieving rapid and economical construction. In this paper, a new retrofitting details and technique is proposed to improve structural capacity and constructability for retrofitting reinforced concrete beams. The components of retrofitting are prefabricated, and the components are quickly assembled using bolts and chemical anchors on site. The details of modularized steel plates for retrofitting have been chosen based on the finite element analysis. To evaluate the structural performance of concrete beams retrofitted with the proposed details, five concrete beams with and without retrofitting were tested. The proposed retrofitting method significantly increased both the maximum load capacity and ductility of reinforced concrete beams. The test results showed that the flexural performance of the existing reinforced concrete beams increased by 3 times, the ductility by 2.5 times, and the energy dissipation capacity by 7 times.

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