Reforço à flexão de vigas em concreto armado com a utilização de chapas pré-fabricadas em UHPC

Abstract

This study investigates the use of prefabricated Ultra-High Performance Concrete (UHPC) panels as a solution for flexural strengthening of reinforced concrete beams. UHPC is an advanced cementitious material that exhibits high compressive strength, elevated toughness, and superior durability in aggressive environments, making it a viable alternative for structural repair and strengthening. The research was developed through experimental approaches, beginning with an in-depth literature review on conventional strengthening techniques, such as reinforced concrete jacketing, application of steel plates, and carbon fiber reinforcement. This review enabled a direct comparison between these traditional methods and the potential of UHPC. The experimental phase involved the fabrication of reinforced concrete beams and UHPC panels, with variations in the presence of internal reinforcement within the panels. Chemical and mechanical anchoring methods were employed to bond the strengthening elements to the beams, aiming to ensure material adhesion and evaluate the influence of bonding on the efficiency of the reinforcement. Structural testing was conducted using four-point bending tests, allowing for the assessment of the load-bearing capacity of the strengthened elements, their deformations, and the crack patterns observed throughout loading. The results demonstrated that beams strengthened with reinforced UHPC panels exhibited a performance increase of 224% compared to unstrengthened reference beams, particularly showing reduced crack widths and higher flexural resistance under serviceability limit states (SLS). Based on the analysis of the results, it was concluded that the use of prefabricated UHPC panels as structural reinforcement represents a promising solution, combining high mechanical performance, minimal architectural impact, and enhanced durability when compared to traditional systems. Furthermore, the study highlights that the proposed method enables the practical application of UHPC in structural rehabilitation projects, optimizing costs and facilitating on-site execution. Thus, this research contributes to the advancement of structural strengthening techniques and paves the way for new UHPC applications in the civil engineering field.