Numerical analysis of the size effect on the shear strength of deep reinforced concrete beams without stirrups

• Grant number: 24/19328-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2025
• End date: April 30, 2026
• Field of knowledge: Engineering - Civil Engineering - Structural Engineering
• Principal Investigator: Alex Micael Dantas de Sousa
• Grantee: Gabriel Ferreira Girotto
• Host Institution: Faculdade de Engenharia (FEIS). Universidade Estadual Paulista (UNESP). Campus de Ilha Solteira. Ilha Solteira , SP, Brazil

Abstract

The models available in the literature for predicting the shear capacity of slabs without transverse reinforcement were mostly calibrated based on the analysis of reduced-scale beams, for which the scale effect is not very significant. However, in the case of slabs of large structures such as dams and tunnels, the scale effect tends to significantly reduce the shear strength of reinforced concrete. For this reason, the shear capacity can be a critical aspect in the design of thick slabs without transverse reinforcement. In this regard, this project proposes (i) to develop a modeling strategy capable of accurately representing the shear failure mechanism of these structural elements, (ii) to investigate the correlation between parameters such as concrete compressive strength and longitudinal reinforcement ratio of beams in the scale effect and (iii) to evaluate the level of accuracy of the main normative codes in relation to the numerical models developed. For this, firstly, finite element numerical models will be calibrated using some experiments with beams with a height greater than 1 m reported in the literature. Subsequently, parametric analyses will be performed by varying the concrete compressive strength class and the longitudinal reinforcement ratio of the models. Finally, the resistance capacities obtained by the numerical models will be compared with those predicted by the main normative codes. Among the main expected results, the aim is to obtain a more comprehensive overview of the level of accuracy of national and international normative expressions in relation to the prediction of the resistance capacity to shear forces of thick slabs without transverse reinforcement.