This paper discusses the behaviour of normal and high strength concrete beams exposed
to elevated temperature. The paper also provides a simple, economical, and reliable
technique that can be used to assess the fire resistance of concrete beams exposed to
multi-action of external loads and elevated temperature simultaneously. The new
technique was verified by testing (36) normal and high strength concrete beams made of
concrete mixes of different w/c and s/c ratios. The tested beams comprised simply
supported and restrained beams, anti-fire coated beams, and beams cooled by different
methods. The results showed that the presented technique is effective and succeeded to
distinguish among the different RC beams. The results also indicated that testing RC
beams subjected to flexural load and then exposed to elevated temperature provided
better understanding to the structural behaviour of the flexural elements in the field. The
results also showed that the restrained RC beams exhibited better fire resistance when
compared to the simply supported RC beams. Using of anti-fire resisting coating
improves the fire resistance of RC beams made of high strength concretes. The results
also emphasised on involving the influence of the cooling methods to evaluate the actual
behaviour of the flexural elements.
KEYWORDS
NSC (Normal Strength Concrete), HSC (High Strength Concrete), Flexural Load, Silica
Fume (S/C), Anti Fire coating, Temperature Development, Techniques of Cooling. |
