الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 229 |  |  |
| | | from | 229 | | |
Abstract
this Research discusses the behaviour of normal and high strength concrete beams and columns exposed to elevated temperature. The Research also provides a simple, economical, and reliable technique that can be used to assess the fire resistance of concrete beams and columns exposed to multi-action of external loads and elevated temperature simultaneously. The new technique was verified by testing (30) normal and high strength concrete beams, 15 RC beams were made of normal concrete mixes of w/c ratio 0.45, 0.5 and 0.6. The other 15 RC beams were made of high strength concrete mixes of s/c ratio 12.5%, 20% and 25, and (30) normal and high strength concrete columns, 15 RC columns were made of normal concrete mixes of w/c ratio 0.45, 0.5 and 0.6, and 15 RC columns were made of high strength concrete mixes of s/c ratio 12.5%, 20% and 25%. The tested concrete specimen is of 150 mm depth, 150 mm breadth, and 1600 mm height.The results showed that the presented technique is effective and succeeded to distinguish among the different RC beams and columns. 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 same thing for RC columns subjected to axial load and then exposed to elevated temperature provided better understanding to the structural behaviour of the compression elements in the field. The results also emphasised on involving the influence of the cooling methods to evaluate the actual behaviour of the flexural and compression elements.Normal strength Concrete beams exposed to fire only exhibited the lowest value of ultimate load by about 15% if it is compared to the other beams exposed to load and fire. And, High strength Concrete beams exposed to fire only exhibited the lowest value of ultimate load by about 95% if it is compared to the other beams exposed to load and fire.Normal strength Concrete columns exposed to fire only exhibited the lowest value of ultimate load by about 30% if it is compared to the other columns exposed to load and fire. Using the anti-fire coating improves the ultimate load with respect to the uncoated elements.