Abstract:
Any structural element has to be design for economy and safely.Beam is one of the main
structural elements and it has to be design appropriately. To guide structural designers selecting
material it is good to carry out comparative study on materials of steel and concrete with respect
to their flexural and fire resistance on the basis of modular ratio.
Modular ratio is the ratio of YoungsModulii of Elasticity of two different materials in
construction of steel and concrete materials. In relation to this gross area cross section of RC
beam changed to the equivalent area of steel and then comparative analysis was done for effect
of flexure and fire on RC and steel beam.
Fire starts when flammable materials light. At that point, it spreads horizontally and vertically
relying upon the compartment limits. A temperature slope is produced through uncovered RC
components. These raised temperatures cause the component's solidness to corrupt and deliver
warm distortions. Basic fire wellbeing of reinforced concrete structures is presently assessed
dependent on the flame evaluations of single components, i.e. columns, beams, walls, and slabs.
However, the overall behavior of the structure during a fire should be assessed to ensure the
safety of the occupants and the fire fighters during evacuation.
Flexural strength is a material property, defined as the stress in a material just before it yields in
a flexure test. The flexural strength represents the highest stress experienced within the material
at its moment yield. It is measured in terms of stress.
The general goal of this paper is to make comparative study on steel and concrete beam with
respect to flexural and fire resistance on the basis of modular ratio and to propose economical
and structurally safe type of beam for construction industry. In order to compare steel and
concrete beam Finite Element Software was used.
The attention of this study would be simply supported rectangular reinforced concrete and I
section steel beam under fire and uniformly distributed load were considered.
Accordingly, from studybending resistance of reinforced concrete beam is higher than I section
steel beam under fire. As well as when I section steel beam increase the size of the cross section
with the same length the bending resistance decrease.
Up on the study it has been recommended that use of reinforced concrete members should have
to increase in Ethiopia for better bending and fire resistance and in Ethiopia there is nothing
done at this field of study so it should have to be a progress from now on as the construction
industry is rapidly growing. Moreover,Ethiopian building code has limitation on fire design
methods, but fire analysis is most important analysis like strength and stability analysis.
