Numerical simulations of the transition from flexural cracking to shear to flexural crushing failures in pre-notched reinforced concrete beams

This study predicts the transition between flexural cracking, shear, and flexural crushing failure modes in reinforced concrete (RC) beams through a series of four-point bending simulations on 48 pre-notched specimens.The upcoming experimental setup explores the influence of key parameters, including: (1) longitudinal reinforcement ratios ranging from 0.13% to 2.26%; (2) slenderness ratios () from 3 to 24; (3) beams of varying size-scale with a constant reinforcement ratio; (4) beams of varying size-scale with a constant reinforcement area.The bridged crack model is applied to assess crack propagation and failure mechanisms, providing insight into the mechanical response, ultimate load capacity, and the critical cracks leading to failure.Dimensionless numbers NP and NC are used to capture the brittleness transitions between different failure modes, offering a unified theoretical framework for evaluating these behaviors.The results provide valuable data for understanding the scale effects on brittleness in RC beams.