Assessment of ductility in codes of practice for reinforced concrete structures

After reading, handling, teaching, and inspecting ACI-318 and EC-2 design codes provisions, which related to the ductility of reinforced concrete structures, should further investigated due to their significance to the safety issues. Therefore, adoption of ductility by current and previous ACI codes are studied and compared with Euro code and two proposed models. Results found that the maximum permissible tensile steel ratio reached 6.7% at concrete strength 82.6 MPa and at low steel grade, the ratio rises as concrete strength increases, resulting in a high level of reinforcement congestion. Furthermore, there is a weakness in the design of double-reinforced beams (with compression reinforcement): ductility can be attained by increasing the tensile steel with a proportional increase in the compression steel, without restricting the amount of steel used, causing unreasonable results. In addition, the item that provides the minimum required steel ratio has a conflict with a previous item from the same section, which requires revision.