1. STRUCTURES in FIRE SiF’2014 paper no 44
A STUDY ON DIFFERENT TECHNIQUES OF RESTORATION OF HEAT DAMAGED R.C. BEAMS
A.B. Danie Roy1, U.K.Sharma2, P.Bhargava3
Department of Civil Engineering
Indian Institute of Technology Roorkee (India)
yahoo.com, 3
STRUCTURES in FIRE
SiF’2014 paper no 44
Introduction
Objectives
The main aim of this research is to investigate the effectiveness of applying HSFRC, FC and GFRP jackets on heated damaged reinforced concrete beams; and to study the behavior of damaged and strengthened elements in terms of strength gain, ductility and failure modes.
To strengthen the heat damaged concrete beams with multiple layers of FRPs, Ferrocement jacketing, high strength fibrous reinforced cementation’s composite material jacketing.
To study the effectiveness of various strengthening techniques on heat damaged RC beams, when cooled naturally.
Strengthening Pattern
Methodology
Heat damaged 900°C after removing loose concrete
A series of 27 reinforced concrete T- beams were constructed using normal strength concrete to investigate the influence of the proposed parameters with different strengthening technique.
The specimens were instrumented with sufficient numbers of thermocouples before the casting, to determine the temperature changes in the specimens throughout the tests.
The specimens shall be heated in an electrical high temperature table mounted furnace. The specimens were subjected to various temperatures ranging 600⁰C and 900⁰C.
The performances of beam were assessed through the load deflection
curves.
Load–deflection relationship of undamaged, heat-damaged and heat-damaged strengthened specimens
Specimen details, Furnace and Heating Regimes
Conclusion
An increase in ultimate load is achieved with GFRP laminate in all heat damaged specimens. Subsequently HSFRC and FC techniques improves the ultimate load capacity of 600oC heat damaged beams, no strength gain was observed in case of 900°C heat damaged beam when compared to undamaged beams. It was observed that the ultimate load cannot be increased using same pattern of strengthening used for different heat damaged beams. The load corresponding to concrete cracking is increased considerably when the damaged beam are strengthen with different strengthening techniques
Details of T- Beam
Heating Regimes
Table mounted Furnace