Repair instead of demolition – Jaguaré Bridge in São Paulo

On 15 November 2018, a section of Jaguaré Bridge along the Marginal Pinheiros expressway in São Paulo sank about two metres. The structure therefore had to be closed and secured by hydraulic supports.
Given that the bridge is part of a main artery serving the metropolis of São Paulo, the city administration decided – after a thorough investigation – against demolition and replacement. Instead, the bridge was to be thoroughly refurbished and structurally reinforced. Right from the start, the authority responsible was advised by MC as a company widely reputed for its know-how and innovations in bridge construction.

 

Major challenges

The main challenges lay in lifting, stabilising and reinforcing the sagging bridge section in the shortest possible time. There were numerous cracks to rectify, structural repairs were required at both the upper and lower faces, and the roadway also needed to be extensively refurbished. High-quality MC solutions and technologies were applied in all phases of the work instituted to tackle these problems. The multifunctional concrete admixture Muraplast FK 300 was used to restore the pier foundations and the concrete carriageways commonly encountered in Brazil. All the cracks requiring repair were sealed with the special resin MC-Injekt 1264 compact – both to prevent aggressive, damaging substances from penetrating the concrete structure again in the future, and to restore the static structure of the concrete.

 

Increased safety

In order to cope with future traffic loads, it was decided to install additional means of structural reinforcement. Since this was not possible with conventional measures such as the provision of further beams or supports, the highly effective

MC-CarbonFiber system (formerly MC-DUR CFK) was used. This consists of carbon fibre-reinforced straps applied to the surface or glued in slots as means of secondary bridge reinforcement. In the case of Jaguaré Bridge, surface-glued MC-CarbonFiber Lamella (formerly MC-DUR CFK Lamelle) reinforcing straps were provided on both the upper face and the undersides of the bridge in accordance with specifications drafted by the structural engineers involved.

Mutually complementary system

Safety and durability are of paramount importance in such undertakings. Hence, all parties involved decided to use MC’s excellently coordinated, high-quality product systems in the other areas of the bridge requiring refurbishment. For example, the structurally enhancing special concrete replacement Nafufill KM 250 and the special mortar Zentrifix CR were used for the reprofiling of the concrete. Offering outstanding application properties and workability, both produced results well above the standards specified.

 

A shining example of engineering excellence

After a possibly record-setting repair time of only five months, Jaguaré Bridge was reopened to road traffic in April 2019, providing a shining example of engineering excellence and also of how project success invariably depends on ensuring the seamless integration and interplay between planning, execution and quality of the systems used. And it has become a model for further projects: As a precaution after this incident, the authorities responsible put in place a comprehensive inspection programme for all bridges – and have already had another bridge repaired using the same methods and approaches employing MC’s proven systems.