Creep and durability of sand-coated glass FRP bars in concrete elements under freeze/thaw cycling and sustained loads

Although the use of fibre-reinforced polymer (FRP) bars to replace steel in reinforced concrete is becoming more common, uncertainty remains concerning the long-term performance of FRP, including the effect of a sustained load on the bond between the FRP bars and the concrete. An experimental study was therefore undertaken to investigate the long-term durability of the bond for various types of bars embedded in concrete: one type of glass FRP, two types of carbon FRP, and conventional steel reinforcing bars. Pullout specimens were tested both statically to failure and under sustained loads for periods of up to 1 year while free-end slip was monitored. Results revealed lower short-term bond strengths for FRP bars relative to steel and significant variability in long-term bond-slip performance among FRP bars of different types. Post-testing investigations revealed damage to bar surfaces at the macroscopic level, as well as broken longitudinal fibres and damage to the surface coatings at the microscopic level.Key words: reinforced concrete, fibre-reinforced polymer (FRP), bond, creep, pullout, sustained loads.

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Diagnosis of concrete structures distress due to alkali-aggregate reaction

Bulletin of the Polish Academy of Sciences Technical Sciences ◽

10.1515/bpasts-2015-0003 ◽

2015 ◽

Vol 63 (1) ◽

pp. 23-29 ◽

Cited By ~ 7

Author(s):

Z. Owsiak ◽

J. Zapała-Sławeta ◽

P. Czapik

Keyword(s):

Concrete Structures ◽

Chemical Exposure ◽

Alkali Silica Reaction ◽

Freeze Thaw ◽

Thaw Cycle ◽

Alkali Aggregate Reaction ◽

Freeze Thaw Cycle ◽

Concrete Elements ◽

Reaction Attack

Abstract Damage and defects observed in concrete elements, such as a network of microcracks, popouts and eflorrescence can be caused by a variety of deleterious processes. The causes can include mechanical (overloading), physical (freeze-thaw cycle) or chemical exposure (sulphate corrosion, alkali-aggregate reaction). This paper analyses distress due to alkali-silica reaction, detected in selected concrete structures. The analysed concrete elements exhibited cracking, exudations and surface popouts. Identification of the presence of hydrated sodium-potassiumcalcium silicate gel can be considered the primary symptom suggestive of an alkali-silica reaction attack. Other damage-causing mechanisms can occur simultaneously.

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Laboratory assessment and durability performance of vinyl-ester, polyester, and epoxy glass-FRP bars for concrete structures

Composites Part B Engineering ◽

10.1016/j.compositesb.2017.02.002 ◽

2017 ◽

Vol 114 ◽

pp. 163-174 ◽

Cited By ~ 57

Author(s):

Brahim Benmokrane ◽

Ahmed H. Ali ◽

Hamdy M. Mohamed ◽

Adel ElSafty ◽

Allan Manalo

Keyword(s):

Vinyl Ester ◽

Concrete Structures ◽

Laboratory Assessment ◽

Glass Frp ◽

Durability Performance ◽

Frp Bars

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Tensile characterization of glass FRP bars

Composites Part B Engineering ◽

10.1016/j.compositesb.2004.05.004 ◽

2005 ◽

Vol 36 (2) ◽

pp. 127-134 ◽

Cited By ~ 58

Author(s):

S. Kocaoz ◽

V.A. Samaranayake ◽

A. Nanni

Keyword(s):

Tensile Characterization ◽

Glass Frp ◽

Frp Bars

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Residual behaviour of glass FRP bars subjected to high temperatures

Composite Structures ◽

10.1016/j.compstruct.2018.07.077 ◽

2018 ◽

Vol 203 ◽

pp. 886-893 ◽

Cited By ~ 7

Author(s):

Simone Spagnuolo ◽

Alberto Meda ◽

Zila Rinaldi ◽

Antonio Nanni

Keyword(s):

High Temperatures ◽

Glass Frp ◽

Frp Bars

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FLEXURAL BEHAVIOR OF FRP BARS AFTER BEING EXPOSED TO ELEVATED TEMPERATURES

The Journal of Engineering Research [TJER] ◽

10.53540/tjer.vol18iss1pp12-19 ◽

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℃.

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