Effect of elevated temperature on the behavior of rc beams strengthened with frp

الملخص EN

Fiber reinforced polymer, (FRP), have been used over the last decade in the form of laminates for strengthening reinforced concrete, (RC), structures.

The non-corrosive characteristics and good fatigue properties of FRP significantly increase the service life of structures.

Its high strength and low weight makes it feasible compared to conventional materials used for retrofit.

Few test data is available on FRP resistance exposed to long term elevated temperature.

This research is being carried out to study the behavior of reinforced concrete beams strengthened with FRP under different environmental conditions such as temperature degree, relative humidity, and thermal durations.

Also, presence of protection layers on FRP laminates was studied.

Different FRP types using carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (GFRP) laminates are used.

The main experimental parameters include different temperature degrees (40, 50, and 60 º C), relative humidity 40% and thermal durations (3, 6 and 9 months).

The measured deflections, failure modes, ultimate carrying capacities, and strain of steel reinforcement and concrete and FRP laminates at critical sections of the beams exposed to different independent environmental conditions are reported.

To determine the design strength of CFRP, and GFRP strengthened beams exposed to long-term environmental conditions as well as to evaluate the strength reduction factors associated with various independent conditions, 15 beams strengthened by CFRP and GFRP are tested.

Results of the experiments show that the failure modes of all specimens are due to yielding of the reinforcing steel in tension followed by rupture of the FRP laminate.

The results also show that beams strengthened with GFRP are more susceptible to aggressive environmental conditions than beams strengthened with CFRP.