Comparative Study of Reinforced Concrete Design Norms (BAEL 91, BS8110 and Eurocode 2) on the Design of a two Span Beam in Cameroon

Abstract

This research compares the beam longitudinal reinforcement areas required by different international design norms or design provisions that deals with the design of reinforced concrete structures namely the French norms: Bétons Armée aux Etats Limites’ (BAEL) 91 revised in 99, the British standards BS8110 and the Eurocode 2(EC2) as used with the Frech national annex ( NF EN 1992-1) and the British national annex (BS EN 1992-1).  The aim of this research was to determine which code or norms provides the most safe and economical design in Cameroon. From the literature, the study first gathered information on the design criteria and beam analysis from the different international norms as well as on the properties of steel reinforcement bars and concrete. The study adopted a continuous beam of 2 spans for the design. Concrete grade 20/25 and 12mm diameter bars were chosen. The yield strength of reinforcing steel, the density of reinforced concrete and the effective depth (d) depended on the requirements of each code. The area of tensile reinforcement obtained by EC2 (both France and Britain National annex) is smaller than that of BAEL 91 and BS8110 at support and at spans as well. This shows that Eurocode 2 results in more economical areas of reinforcement steel bars than when designing with BAEL 91 or BS8110.  Since Eurocode 2 results in smaller required steel reinforcement areas, this decreases the steel reinforcing bars congestion in a structural member. The BEAL91 has the highest required steel reinforcement area due to its lower yield strength amongst all the other codes under study. The study recommends that Cameroon should as a matter of urgency draw up her national annex and starts the full implementation of Eurocode 2 in order to enjoy its manifold benefits.