Theoretical model for the determination of plastic rotation capacity in reinforced concrete beams
R. N. F. do Carmo, Department of Civil Engineering, ISEC-Polytechnic Institute of Coimbra Portugal
S. M. R. Lopes, Department of Civil Engineering, FCTUC-Polo II-University of Coimbra Portugal
L. F A. Bernardo, Department of Civil Engineering, University of Beira Interior Portugal
Evaluating the ducility of reinforced concrete beams is essential in order to avoid a fragile collapse of the structure by ensuring an adequate deformation at ultimate load. This paper presents a theoretical model for the calculation of plastic rotation. Results obtained are compared with those obtained from an experimental programme in which a set of beams were tested to failure. From the comparison, a good agreement between theoretical and experimental results was achieved. The proposed theoretical model considers the influence of certain factors: steel properties, concrete strength, section depth, and the tension stiffening effect. Concrete strength, particularly, is an interesting parameter since for high-strength concrete, the ultimate concrete strain, εcu, decreases as the concrete strength increases.