Geocisa (Spain)

Reinforcement corrosion leads into several damages which influence the structural load-bearing capacity, among which can be mentioned the cracking of concrete cover. This work study formulations to estimate the crack width of structural elements from the data of corrosion rate measured in two structural elements, made in 1990, with chlorides added in the concrete mix. These elements, one T beam and one column, were exposed at the atmosphere of Madrid, Spain. Two expressions have been fitted to the results: w = k Px / (c/f) and w = k Px / Ro, where w is a crack width in the time, k is a proportional factor, Px is the corrosion penetration in the time, c/f is the concrete cover/diameter relation and Ro is the original radius of the bar. The first expression has resulted the most adequate.

The control tower of the Alicante airport is 47 m high and is composed of a concrete core, which has elevators, stairs, and a steel structure containing the technical, resting and the air-traffic control rooms. This steel structure is supported by a concrete pole with a tubular section, which is connected at different levels to the concrete core by means of steel trusses. This paper presents results of an investigation on the causes and remedies for vibrations in an air-traffic control tower. It has been shown that wind induced vibrations may disturb air traffic control for acceleration values which are lower than the thresholds as defined in ISO Standards. Besides small differences between theoretical and experimental results, buffeting analysis through numerical methods has proved to be useful to investigate the behaviour of tuned mass dampers and to adjust their design when applied to structures with well defined vibration frequencies.

This report describes several tests that are being carried out on a viaduct near Madrid City, whose reinforcements have been seriously damaged by corrosion. These tests consist in measuring corrosion potentials and in a time soon to come, they will include the measurement of corrosion rates by means of the apparent Polarization Resistance. A methodology of laboratory tests to evaluate the protective capacity of the repairing system used towards the reinforcements is also included. Tests results have reported that the repairing materials employed do not fit the repassivating and protective function they should satisfy. Finally, it is also recalled to attention the real need in developing suitable test specifications able to provide a characterization of these repairing materials when they are going to be employed in structures damaged by corrosion in reinforcements.