scholarly journals Composite GFRP bars as reinforcement of concrete members under axial force and bending moment

2014 ◽  
Vol 13 (3) ◽  
pp. 167-174
Author(s):  
Piotr Szymczak ◽  
Paweł Olbryk ◽  
Maria Kamińska

This paper discusses concrete members reinforced internally with composite GFRP bars (Glass Fibre Reinforced Polymer). The studies are focused on members under axial force and bending moment. Experimental studies of 4 RC columns loaded with compressive axial force, longitudinally and transversally reinforced with GFRP bars were discussed. Columns had cylinder shape with the nominal diameter of 200mm and height of 600mm. Longitudinal reinforcement contained six bars with 11mm diameter and transversal reinforcement of continuous spiral bars # 4 and #8 with spacing equal to 45mm and 60mm. Studies show that the GFRP reinforcement has very good adhesion to concrete and,in failure state reaches stresses adequate to longitudinal strains of members. This paper proves that the interaction curves can be determined on the same strain state basis as used in RC members according to EC2.

2000 ◽  
Vol 27 (5) ◽  
pp. 890-898 ◽  
Author(s):  
Tara Hall ◽  
Amin Ghali

This paper presents the results of an experimental investigation of the long-term deflection behaviour of concrete shallow beams reinforced with glass fibre reinforced polymer (GFRP) bars. The long-term deflections of the GFRP-reinforced beams are compared to deflections of identical beams reinforced with steel bars. All beams were under sustained loading for approximately 8 months. The variables were the level of sustained loading and the reinforcement materials: steel or GFRP. The experimental immediate and long-term deflections of both the steel- and the GFRP-reinforced beams were compared to calculated deflections using the CEB-FIP Model Code 1990, and the ACI 318-95 code using the recommendations of ACI Committee 209; these references are for steel reinforced concrete members. The test results indicate that under similar loading conditions and the same reinforcement ratio, the GFRP-reinforced beams had long-term deflections, due to creep and shrinkage, 1.7 times greater than those of the steel-reinforced beams. A comparison of the theoretical and experimental immediate and long-term deflections indicates that the CEB-FIP Model Code 1990 gives reasonable predictions for all beams, and that the ACI 318-95 code, using the ACI Committee 209 recommendations, overestimates the deflections due to the combined effects of creep and shrinkage.Key words: glass fibre reinforced polymer (GFRP), steel, reinforced concrete, long-term, deflections, flexure, elastic modulus.


2021 ◽  
Author(s):  
Dave Ametrano

The use of fibre reinforced polymer (FRP) bars is increasing in construction as an alternative to conventional steel rebars. This thesis investigates the bond behaviour of glass fibre reinforced polymer (GFRP) bars embedded in high performance concrete (HPC) and ultra-high performance concrete (UHPC). In this study, the bond characteristics of sand coated GFRP bars embedded in 70-175 MPa concrete were explored. Beam and pullout tests were performed to determine the effects of the concrete strength, bar diameter, embedment length, and concrete cover on the bond behaviour of GFRP bars. Based on the analysis, the development lengths for the GFRP bars were determined and then compared to requirements provided by design codes. It was concluded that the design code lengths could be reduced by 20% while still maintaining a factor of safety of two over the development lengths determined through this study. This reduction can be applied when the GFRP bar is surrounded by sufficient transverse reinforcement, such that adding additional reinforcement would not affect the bond strength. Reducing the amount of GFRP reinforcing material needed, results in a lower overall cost of construction.


2013 ◽  
Vol 40 (11) ◽  
pp. 1050-1059 ◽  
Author(s):  
Ehab A. Ahmed ◽  
Christian Dulude ◽  
Brahim Benmokrane

The behaviour of concrete bridge barriers reinforced with glass fibre-reinforced polymer (GFRP) bars has been investigated at the University of Sherbrooke in collaboration with the Ministry of Transportation of Quebec (MTQ) through a two-phase research project. This paper presents the test results of MTQ Type 311 barrier prototypes under static (Phase I) and pendulum impact (Phase II) loading conditions. The test program included two full-scale 2.6 m long barrier prototypes for laboratory testing under static loads (Phase I) and four full-scale 11 m long barrier prototypes for field impact tests (Phase II). The laboratory static tests included one prototype totally reinforced with GFRP bars and one totally reinforced with steel bars for comparison, whereas the pendulum impact tests included two replicas totally reinforced with GFRP bars and another two totally reinforced with conventional steel bars. The barrier walls of the six prototypes were provided with the same reinforcement amount of GFRP and steel bars (No. 20 GFRP @ 200 mm and 20M steel bars @ 200 mm). The performance of the GFRP-reinforced concrete (GFRP-RC) barriers was evaluated and compared with that of their steel-RC counterparts. The results of this investigation revealed that the behaviour of the GFRP-RC concrete bridge barriers of MTQ Type 311 is similar to their steel-RC counterparts.


Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1132
Author(s):  
Jeonghyeon Lim ◽  
Young-Jong Kang ◽  
Jeonghwa Lee ◽  
Seungjun Kim ◽  
Keesei Lee

If bending and torsional moments are applied to an I-shaped beam member, the coupling of those two forces could reduce the bending moment capacity of that member. Therefore, the interaction between bending and torsional moments is an important issue for horizontally curved members that are always simultaneously subjected to bending and torsion. In this study, the behavior of the horizontally curved steel I-beam was investigated through numerical analysis. The ultimate state of sharply curved members that showed large displacement was defined in accordance with the stiffness reduction ratio to consist of strength curves. Based on the analysis results, interaction curves were established, and a strength equation was derived. The uniform torsional moment capacity, curvature, and slenderness parameters were considered in the equation, which were the main factors that affected the ultimate strength of curved members. The curvature effect was considered individually, so that the strength of the straight or curved girder could be estimated with a unified equation. To verify the accuracy of the suggested equation, experimental studies were also conducted. Consequently, the suggested equation shows very good agreement with the test results, and is expected to provide useful information for the design of curved members.


2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Wei Wang ◽  
Liang Chen ◽  
Caidong Guo

In order to investigate the strength design problem of the brazed aluminum plate-fin heat exchanger header under complex external piping loads, the limit load interactions of the header under combined piping loads are studied in this paper. To establish the limit piping load interaction curves, nonlinear finite element analysis assuming the elastic perfectly plastic material model is performed by using the commercial finite element analysis software ANSYS and multiple piping load combinations, which are the combination of orthogonal bending moment components, torque component-shear force component, bending moment component-axial force component, compound bending moment-axial force component, and torque component-compound shear force, of the header with six opening ratios ranging from 0.5 to 1 are explored. The results of the interaction diagrams show that the feasible combined piping load zone of the header derived from the interaction curves can be simplified as a triangular zone determined by the individual limit piping load components safely and the simplified feasible zone is suggested to be used for establishing a simplified safety assessment method for the header under combined piping loads.


2004 ◽  
Vol 31 (4) ◽  
pp. 539-552 ◽  
Author(s):  
Ehab El-Salakawy ◽  
Radhouane Masmoudi ◽  
Brahim Benmokrane ◽  
Frédéric Brière ◽  
Gérard Desgagné

This paper presents the results of a pendulum impact test that was carried out on full-scale types PL-2 and PL-3 concrete bridge barriers reinforced with glass fibre reinforced polymer (GFRP) bars. A new corrosion-free connection between the barrier wall and the slab using GFRP bent bars was investigated. For comparison purposes, the impact test was also performed on identical concrete barriers reinforced with conventional steel. A total of eight full-scale 10-m-long barrier prototypes were constructed and tested. The tests included four PL-2 and four PL-3 prototypes. For each type of barrier, two prototypes were reinforced with GFRP sand-coated bars and the other two were reinforced with steel bars. Pendulum crash tests using a 3.0-t pear-shaped iron ball were performed under the same conditions for each type of barrier. The behaviour of the barriers was evaluated in terms of cracking pattern, crack width, and strains in reinforcing bars. The results of this investigation led to the conclusion that the behaviour of PL-2 and PL-3 concrete bridge barriers reinforced with GFRP bars is very similar to that of their counterparts reinforced with conventional steel in terms of cracking, energy absorption, and strength.Key words: concrete bridges, bridge barriers, glass FRP bars, impact, pendulum crash test.


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