Application of the Modified Compression Field Theory (MCFT) for Shear Analysis of Reinforced Concrete Beams

This paper presents a streamlined implementation of the Modified Compression Field Theory (MCFT) as a practical computational basis for unified shear assessment of reinforced concrete beams.The scope is intentionally limited to beams reinforced with internal steel longitudinal bars and steel stirrups, to (i) document the governing MCFT relationships as implemented in a VBA-based code, (ii) verify stable solution behavior through systematic parametric runs, and (iii) establish a robust baseline for subsequent extensions to beams reinforced with GFRP longitudinal bars and/or stirrups and to shear-strengthened members using externally bonded systems.A parametric study is conducted for a deep-beam configuration by fixing the shear span-to-depth ratio at / = 2 and varying the effective depth , longitudinal reinforcement ratio , and transverse reinforcement ratio over representative design ranges.The implementation explicitly captures key MCFT mechanisms, including the evolution of crack angle, longitudinal strain, and tensile stress factor, and the resulting partition of shear resistance into concrete and transverse-steel contributions.Across the analyzed cases, the predicted ultimate shear capacity exhibits clear sensitivity to reinforcement detailing and member depth, confirming the framework's ability to capture interaction effects between concrete cracking behavior and reinforcement response.The presented implementation and generated dataset provide a consistent foundation for an expanded, interactive unified tool covering steel-and FRP-reinforced beams, with and without external strengthening systems (FRP, FRCM, and SRG), supported by published experimental databases.