Accuracy evaluation of ACI and EC2 on minimum reinforcement ratio for RC beams

Abstract

Sectional analysis by using software Response2000 has been carried out to calculate minimum flexural reinforcement ratio by considering the size effect and the cross-section shape of the beam which are completely neglected by ACI 318-19 and EC2, as well as extending the current upper limit on the yield strength of reinforcement (fy) on ACI 318-19 and EC2 to enable the usage of high strength steel reinforcement (HSSR). A total of 1920 test results were used to analyze the parameters affecting the minimum flexural reinforcement ratio to ensure a ductile failure mode. The research has revealed that the minimum flexural reinforcement ratio is a function of 4 variables: concrete compressive strength (f’c), reinforcement yield strength (fy), d/h ratio, and cross-section shape. Furthermore, this report has shown that ACI 318-19 is more conservative than EC2 for predicting the minimum reinforcement ratio. Finally, new equations have been proposed to calculate the minimum flexural reinforcement ratio.