Determination of the cracking moment of reinforced concrete sections corresponding to the bi-linear stress-strain diagram of concrete

Abstract

This paper presents in detail the method for determining the cracking moment of rectangular reinforced concrete sections, taking into account the nonlinear behavior of concrete simplified as the bi-linear stress-strain diagram according to TCVN 5574 – 2018. The article also compares the cracking moment calculated according to the approximate method presented in TCVN 5574 – 2018 and calculated according to the method established based on the bi-linear model with different reinforcement ratios. The calculation results have showed that: (1) the cracking moment increases linearly as function of tensile reinforcement ratio and of compression reinforcement ratio; (2) the tensile reinforcement ratio has a great influence on the cracking moment while the influence of compression reinforcement ratio is insignificant; (3) the approximate method presented in TCVN 5574 – 2018 underestimates the cracking moment of the section, especially in the case of high tensile reinforcement ratio.