Reinforcement concrete beams with external steel elements

Abstract

The reinforcement of structural elements is widely practiced worldwide. It can be applied due to deterioration of the concrete, either due to age, change of use, extensions, or updating of the design code. However, it is sometimes used with inappropriate materials or without technical supervision or structural design. The main purpose of this paper is to investigate the method of strengthening based on the external addition of steel elements and to determine its influence on the flexural load-carrying capacity of reinforced concrete (RC) beams. For the same area of external steel, two types of beams are defined: the first one with cold-formed angle sections at the bottom corners, and the second one with a steel plate in the center of the tension face of the beam. The behavior of a total of 12 beams under monotonic and cyclic loading is experimentally studied. The connection was made with post-installed expanding bolts, without adhesives. The configuration that presents adequate results in terms of strength, flexibility, and energy, this obtained with the addition of a steel elements. On the other hand, the use of angled sections, contrary to expectations, reduces the load-carrying capacity and ductility of the section.