An analytical model for crack control in reinforced concrete elements under combined forces

A rational model for design with crack control of reinforced concrete structures is presented. The model, based on the Softened Truss Theory, allows crack width in reinforced concrete elements under combined axial, flexure, shear and torsion forces to be determined. By calculating the corresponding principal tensile strains, normalized with respect to an appropriate reference value, and by assuming suitable stress-strain relationships, the equilibrium and compatibility conditions are imposed. Thus an appropriate iterative procedure allows strain contour as well as cracking width to be determined. The results obtained are presented in graphs to ease practical and design applications.