Influence of elevated temperatures on the bond behaviour of ribbed Gfrp bars in concrete

2021 ◽  
pp. 104119
Author(s):  
Inês C. Rosa ◽  
João P. Firmo ◽  
João R. Correia ◽  
Pietro Mazzuca
Keyword(s):  
Elevated Temperatures ◽  
Bond Behaviour ◽  
Gfrp Bars

Influence of Test Configuration on Bond Strength of GFRP Bars

2019 ◽  
Vol 292 ◽  
pp. 217-223 ◽  
Author(s):  
Ondřej Janus ◽  
Frantisek Girgle ◽  
Vojtech Kostiha ◽  
Petr Štěpánek ◽  
Pavel Sulak
Keyword(s):  
Bond Strength ◽  
Concrete Cover ◽  
Silica Sand ◽  
Beam Test ◽  
Bond Behaviour ◽  
Test Configuration ◽  
Gfrp Bars ◽  
Pull Out ◽  
Frp Reinforcement ◽  
Gfrp Reinforcement

It is well-known that test configuration affects bond behaviour of steel reinforcement, but this effect has not yet been sufficiently quantified when using FRP reinforcement. This paper presents partial results from an ongoing experimental programme that deals with the bond strength of GFRP bars with concrete, with regards to the effect of the surface treatment of the rebars and test configuration. A modified beam test is presented in this study along with a pull-out test with an eccentric bar placement. The bond strength of GFRP reinforcement with sand-coated treatment using silica sand and ribbed type with milled ribs was tested. The sand-coated bars exhibit different bond behaviour compared to the ribbed ones due to different forces transfer from the reinforcement to the concrete. Thickness of the concrete cover layer also has a significant effect on the bond behaviour of the reinforcement.

scholarly journals Bond characteristics of glass fibre reinforced polymer bars embedded in high performance and ultra-high performance concrete

2021 ◽  
Author(s):  
Dave Ametrano
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Ultra High Performance Concrete ◽  
Bond Behaviour ◽  
Gfrp Bars ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Bond Characteristics

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.

Bond Behaviour of GFRP Bars with Concrete at Normal and High Temperatures

2021 ◽  
pp. 275-286
Author(s):  
Jahanzaib ◽  
Shamim A. Sheikh ◽  
Zahra Kharal ◽  
Husham Almansour
Keyword(s):  
High Temperatures ◽  
Bond Behaviour ◽  
Gfrp Bars

scholarly journals FLEXURAL BEHAVIOR OF FRP BARS AFTER BEING EXPOSED TO ELEVATED TEMPERATURES

2021 ◽  
Vol 18 (1) ◽  
pp. 12-19
Author(s):  
Dr. Sherif El-Gamal ◽  
Abdulrahman M. Al-Fahdi ◽  
Mohammed Meddah ◽  
Abdullah Al-Saidy ◽  
Kazi Md Abu Sohel
Keyword(s):  
Flexural Strength ◽  
Elevated Temperatures ◽  
Flexural Modulus ◽  
Flexural Behavior ◽  
Test Results ◽  
Gfrp Bars ◽  
Reinforced Polymer ◽  
Significant Strength ◽  
Glass Frp ◽  
Frp Bars

This research study investigates the flexural behavior of fiber reinforced polymer (FRP) bars after being subjected to different levels of elevated temperatures (100, 200 and 300°C). Three types of glass FRP bars (ribbed, sand coated, and helically wrapped) and one type of carbon FRP bars (sand coated) were used in this study. Two testing scenarios were used: a) testing specimens immediately after heating and b) keeping specimens to cool down before testing. Test results showed that as the temperature increased the flexural strength and modulus of the tested FRP bars decreased. At temperatures higher than the glass transition temperature (Tg), significant flexural strength and modulus losses were recorded. Smaller diameter bars showed better residual flexural strength and modulus than larger diameter bars. The immediately tested bars showed significant strength and modulus losses compared to bars tested after cooling. Different types of GFRP bars showed comparable results. However, the helically wrapped bars showed the highest flexural strength losses (37 and 60%) while the sand coated bars showed the lowest losses (29 and 39%) after exposure to 200 and 300℃, respectively. The carbon FRP bars showed residual flexural strengths comparable to those recorded for the GFRP bars; however, they showed lower residual flexural modulus after being subjected to 200 and 300℃.

scholarly journals Research on the residual tensile strength of composite reinforcing bars exposed to elevated temperatures

2021 ◽  
Vol 1205 (1) ◽  
pp. 012011
Author(s):  
I Rozsypalova ◽  
J Prokes ◽  
Đ Cairović ◽  
F Girgle ◽  
P Danek ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Steady State ◽  
Analytical Approach ◽  
Elevated Temperatures ◽  
Reduction Rate ◽  
Testing Procedure ◽  
Reinforcing Bars ◽  
Gfrp Bars ◽  
Bar Diameter

Abstract Paper describes a testing procedure for the determination of tensile strength of the composite reinforcing bars subjected to elevated temperatures. Experimentally obtained results on GFRP bars with different diameter are presented and discussed. Moreover, a brief comparison with an analytical approach was included. Almost identical temperature reduction rate of tensile strength was observed for all tested specimens, regardless diameter of the bar. Therefore, it can be expected, that different bar diameter should not significantly affect the results especially if steady state conditions were assumed.

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