STRUCTURAL ASSESSMENT OF REINFORCED CONCRETE BEAMS RETROFITTED WITH CARBON FIBRES AND STEEL PLANKS SUBJECTED TO BENDING

Medina D.; Copa F.; Copa C.; Málaga-Chuquitaype C. · World Conference on Earthquake Engineering proceedings (2021)

Resumen

This paper presents and discusses the structural behaviour of reinforced concrete beams subjected to bending with two retrofit systems, namely: (i) carbon fibre reinforcement and (ii) epoxy-bonded steel sheets. First, the beams were tested under four-point bending before repairing. In order to achieve a monolithic action, epoxy resin was used for adhering the retrofitting plates at the cracked zones and in the compression areas where the original concrete was replaced with construction grout. A total of 12 full-scale beam specimens were tested, 3 reinforced with carbon fibre and 3 reinforced with steel plates. The retrofitted results were compared against those of the 6 beams tested without reinforcement. All beams were tested in the Structural Laboratory of the Faculty of Civil Engineering at the UNSA (San Agustin National University from Arequipa) by applying 2 symmetric concentrated loads at mid-span. The structural retrofitting techniques examined herein were found to perform well and failure was not observed at the same repaired location due to adequate adhesion between grout and concrete. The experimental results of the reinforcement system with steel plates and a steel quantity of 0.3048% demonstrate an adequate structural behaviour, having increased the beam’s bending capacity by 60% in comparison with the original design. Significant improvements in ductility were also documented even in those cases where the failure mode involved the detachment of the reinforcing steel plate before yielding. On the other hand, the experimental tests of the carbon fibre reinforcement system experienced a fragile failure typical of this reinforcement given its strain capacity. An overall increase of 30% in the final flexural strength was observed. © The 17th World Conference on Earthquake Engineering.

Instituciones: Universidad Nacional de San Agustín de Arequipa