Manifestações patológicas em estruturas de concreto protendido

Abstract

The present study addresses pathological manifestations in prestressed concrete structures, highlighting their technical relevance in view of the increasing use of this structural system in medium- and large-scale projects. Prestressed concrete is widely employed because it allows for reduced cross-sections, increased spans, and improved control of cracking. However, it presents high sensitivity to design, construction, and maintenance failures, particularly with regard to the integrity of prestressing tendons. The objective of this study is to analyze the main types of pathologies affecting prestressed structures, as well as the methods for their identification and the associated repair and maintenance strategies, aiming to contribute to the safety, durability, and performance of these structures. The adopted method is based on a bibliographic review of Brazilian technical standards, especially ABNT NBR 6118:2023 and ABNT NBR 14931:2023, in addition to scientific articles, dissertations, and recent case studies related to the subject. The main pathological mechanisms are discussed, such as sudden tendon rupture, loss of prestress, cracking, excessive displacements, and water infiltration, emphasizing their causes, consequences, and interrelationships. In addition, the study presents the main methods for identifying pathologies, highlighting non-destructive testing techniques such as ultrasonic testing, rebound hammer testing, electrical resistivity, thermography, and the RIMT test, demonstrating their importance in the early diagnosis of internal damage. As a result, it is observed that most pathologies in prestressed concrete structures are associated with deficiencies in technological control, exposure to aggressive environments, and the lack of systematic preventive maintenance. It is concluded that the adoption of integrated strategies for inspection, diagnosis, repair, and maintenance, combined with strict compliance with technical standards and the involvement of qualified professionals, is essential to extend the service life of prestressed structures and ensure adequate levels of structural safety over time. Keywords: prestressed concrete; pathological manifestations; non-destructive testing; structural durability; structural maintenance.