The “General Rafael Urdaneta” Bridge (GRUB) has six main spans that correspond to the Piers numbered 20 to 25 following the West-East direction. In each of the piers there are 4 groups of 16 wire ropes each, giving a total of 64 wires per pier and a grand total of 384 for the 6 piers of the bridge. Each group of wire rope works individually on each side of the pier to help support the projecting structure of the bridge. The wire ropes are anchored to the structure at each end, the lower anchor is fixed laterally close to the north and south ends of the deck, and the upper anchor is fixed to an apparatus located at the top of the saddles, approximately at 92 m above water level. The diameter of each wire rope is 8 cm and its approximate length is 95 m (total area of all the wire ropes is 9,168.42 m2). The last maintenance performed to the ropes was in 1993, when a coating system that consists of one coat of an organic zinc rich primer and one coat of a high build bituminous aluminum coating was applied to a surface prepared by a power tool consisting of a set of three rotating wire brushes and regular hand wire brushes. Since then, they have been subject to the attack of an aggressive marine environment, and its abrasion. This exposure has caused corrosion alongside the body of the cables, being most frequently found on the northern face of the cables (direction of the prevailing winds). In some cases, corrosion has attacked the base metal of the wire ropes. Due to the magnitude of the damage found in a 1998 inspection, it was recommended that the entire coating system be removed and a new one be applied similar to the one described above.

The objective of this work is to present the results of the inspection performed to the wire ropes of the GRUB, to evaluate the actual conditions of the tension on the cables and the installed coatings system, along with the factors that have affected its performance, and prepare the specifications for the recoating of the cables, as an essential means of guaranteeing the performance of the wire ropes, as an structural member of the bridge. Furthermore, the procedure used to retension the cables is shown.

Subject
Coating inspection, Zinc rich coatings, Coatings, Substrates, Wiring, Coating damage, Cables, Anchors, Corrosion protection, Wind, Soluble salts, Bridges, Coating systems
Keywords:
Cables, Bridge, Coatings, Evaluation, Corrosion, Retension
© 2001 Association for Materials Protection and Performance (AMPP). All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photocopying, recording, or otherwise) without the prior written permission of AMPP. Positions and opinions advanced in this work are those of the author(s) and not necessarily those of AMPP. Responsibility for the content of the work lies solely with the author(s).
2001
Association for Materials Protection and Performance (AMPP)
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