Procedimentos para reforço de lajes nervuradas utilizando mantas de fibra de carbono

Abstract

Reinforced concrete is undoubtedly one of the main structural materials used in civil construction in Brazil and around the world. As with all types of structures, those made of reinforced concrete may require reinforcement in many situations, such as: failure in design or execution, change in the use of the building, deterioration over time, variation in the load of use, etc. In these cases, the adoption of reinforcement techniques aims to provide the structural system with the necessary conditions to guarantee stability and safety. There are many options for structural reinforcement and among these is the use of carbon fiber blankets. The main characteristics of this reinforcement system are its high mechanical strength and low specific weight, as well as its good adaptation to different part geometries. In this context, the paper presents execution and design procedures related to the use of carbon fiber blankets as reinforcement in reinforced concrete slabs consisting of bidirectional ribs, following recommendations established by ABNT NBR 6118, ABNT NBR 6120 and ACI 440.2R. These procedures are applied to an example of a ribbed slab reinforced to meet the conditions required by a different accidental load value corresponding to the new use of the building.