Control of Flexural Cracking in Reinforced Concrete

Abstract

Excessive cracking is one of the common causes of damage in concrete structures and results in huge annual cost to the construction industry. Most of the current design approaches for crack control are empirical and based on observed crack widths in laboratory specimens tested under short-term loads. Most approaches fail to adequately model the increase in crack width that occurs with time due to shrinkage. In this paper, an alternative design method for flexural crack control that overcomes many of the limitations of the current code approaches is proposed. The proposed method takes into account the time-dependent development of cracking and the increase in crack widths with time due to shrinkage. The crack width calculation procedure has been shown to provide good agreement with the measured spacing and width of cracks in a variety of slabs and beams tested in the laboratory under sustained service loads.