Taye, Shifferaw (PhD)Sisay, Alemu2018-07-242023-11-112018-07-242023-11-112009-11http://etd.aau.edu.et/handle/12345678/9888This thesis is concerned with the effect of change in yield strength of reinforcement steel on the safety and strength of reinforced concrete beams and columns. Of different possible types of beams and columns, simply supported beams and short columns are considered in this study. Parameters like moment capacity, total steel area, neutral axis depth, ultimate load curvature and stiffness of the beam and total steel area of the column are taken. The general trend observed in behavior due to the change in yield strength is assessed and have been presented graphically. Both the beam and the column are first designed using limit state design method employing the appropriate partial safety factors for loads and materials. Next they are designed for service loading keeping other conditions the same as before using a factor of safety equal to one for concrete and steel. Then the difference in capacity between the design results is evaluated. As this difference is the reserve capacity we have as a safety margin, the effect of the change in yield strength is evaluated with respect to this capacity and presented graphically to show that by how much safety margins are compromised. Finally, conclusions and recommendations have been made based on the findings Key words: over–reinforced concrete beams, under–reinforced concrete beams, yield strength of steel, capacity parameter.enover–reinforced concrete beams; under–reinforced concrete beams; yield strength of steel; capacity parameteThesis