Abstract:
The majority of structural building structures are designed and constructed in reinforced concrete
which are mainly depends upon availability of the constituent materials and the level of skill
required in construction, as well as the practicality of design codes.
Reinforced concrete building used high material usage because of their increased dead load,
hazardous formwork. The use of steel in construction industry is very low in Ethiopia compared
to many developing countries. There is a great potential for increasing the volume of structural
steel in construction, especially in the current development. In Ethiopia, structural steel is not
using as an alternative construction material and not using it where it is economical in a heavy
loss for the country. Steel-concrete composite construction has gained large acceptance all over
the world as a substitute for pure steel and pure concrete construction. In Ethiopia, many
consulting engineers are reluctant to accept the use of composite steel-concrete structure because
of its unfamiliarity and complexity in its analysis and design. However, this approach is a new
concept for construction industry.
This research discusses comparative study of reinforced concrete, structural steel and steelconcrete composite building structures by analysis of G+5, G+8 and G+11 modeling. Modal
response spectrum analysis for seismic zone III was carried out based on ES EN-8 using packaged
software ETABS 2016. The span length, interstorey height and loading systems was kept constant.
The main parameter discussed on this study are the sory response such as storey shear, storey
drift, story displacement, modal frequency and time period; construction costs such as direct cost;
and self-weight of the buildings.
As per the comparisons made, the steel-concrete composite building showed a reduction in base
shear, story drift and story displacement for G+5, G+8 and G+11 as compared to the reinforced
concrete and structural steel building. And also the steel-concrete composite building showed a
reduction in modal period compared to the reinforced concrete and structural steel building for
G+5; increased compared to the reinforced concrete and reduced compared to structural steel
building for G+8 and G+11. The reinforced concrete building showed a reduction in modal
frequency for G+5, G+8 and G+11 compared to the steel-concrete composite and structural steel
building. The structural steel building showed a lighter in self-weight for G+5, G+8 and G+11 as
compared to reinforced concrete and steel-concrete composite building whereas steel-concrete
composite building is lighter compared to reinforced concrete building at G+5, G+8 and G+11.
The steel-concrete composite building showed a reduction in direct cost as compared to the
reinforced concrete and structural steel building for G+8 and G+11, but it showed an increased
in direct cost compared to reinforced concrete building for G+8 whereas reinforced concrete
building is cheaper compared to structural steel building at G+5, G+8 and G+11.