Minimum reinforcement revisited

Abstract

Minimum reinforcement has a significant impact on the economy and sustainability of concrete structures. Current code formulations do not always address all practical cases, in particular the amount of minimum reinforcement required in thick members, for which codes generally over‐estimate the necessary values. Also, some codes have formulations which are only applicable to limited conditions, or, as is the case of Eurocode 2, have a general formulation, which, however, is not easy to understand, is not complete, and still over‐estimates the necessary reinforcement. In the light of the revision of Eurocode 2, this paper proposes a general formulation for general cross sections formed by a combination of rectangles (rectangular, flanged, or box sections) subjected to both bending and axial force based on mechanical principles and provides a reduction in minimum reinforcement for thick members by allowing the formation of larger interior cracks while providing adequate control of surface cracks.