Refurbishment and waterproofing of the deck of the Lira Bridge, Madrid.

Introduction
This is a pedestrian footbridge that allows citizens to cross the M-30, connecting Moratalaz with the Barrio de la Estrella, since 2002, when the Madrid City Council modified the project so as not to demolish the Lira bridge, and to reconvert it for cycling and pedestrian use.

The refurbishment has now focused on the elements of the concrete overpass (piers, abutments, deck and fascia). The planters have also been removed, and this space has been integrated into the new pavement, acting on the bridge’s waterproofing and drainage systems.

Description

The action on the deck consisted of demolishing the old paving and the planters, in order to waterproof them with FLEXITEC Two-component mortar formulated with cements, synthetic resins, which forms a completely waterproof coating with very high flexibility and great adherence and which complies with the requirements of the EN 1504-2 standard. Finally, it is finished with a coloured drying concrete. Executing the half reeds and spot repairs with PROPAM® REPAR 30 repair mortar, which meets the requirements of class R3 of EN 1504-3.

In the areas of the pavement where it has been necessary to redefine the slopes, as in the case of the eaves and behind the petriles, PROPAM® RECRECIDO PRONTO cementitious mortar with normal setting and compensated shrinkage has been used for the execution of screeds of rapid commissioning in thicknesses of 10 to 80 m, before waterproofing with FLEXITEC.

Structural concrete repairs have been carried out with PROPAM® REPAR TECHNO 40 MCI, a thixotropic, fibre-reinforced repair mortar and migratory corrosion inhibitor, specially formulated for the repair of concrete in aggressive environments. It acts on corrosion phenomena by delaying the onset of corrosion and also slowing down its speed once it has started.

Finally, the entire structure was protected with BETOPAINT FLEX, a coating for the protection of concrete and mortar against carbonation, waterproof, with a decorative finish and resistant to atmospheric agents.

Technical Note

Today, sustainable construction has become a must-have goal for homeowners around the world. Much attention has been paid to reducing the use of concrete and minimising energy and water consumption, however, one aspect that is often overlooked is the durability and lifespan of the structure. This is undoubtedly one of the key parameters influencing structural sustainability.

Adequate reinforcement protection therefore directly affects maintenance costs, as corrosion of reinforcing bars is the cause of costly repairs and economic losses. It is crucial, therefore, to extend the service life of new and existing structures; and to proactively delay the onset of corrosion and keep corrosion rates low after the onset.

At Molins we use the most advanced technology in Migratory Corrosion Inhibition (MCI® from Cortec Corporation), on the basis of which we have developed the most advanced technical mortars on the market, PROPAM® REPAR TECHNO 40 MCI and PROPAM® REPAR TECHNO FLUID MCI, for the repair and protection of reinforced concrete structures. These mortars meet the requirements of the EN 1504-3 class R4, EN 1504-2 and EN 1504-7 standards, providing a solution of maximum durability in the repairs carried out.

– Structural concrete repair mortar Class R4.

– Coating (C) for protection against penetration (PI), moisture control (MC) and

increase in resistivity by limiting the moisture content (IR).

– Coating for the protection of reinforcement against corrosion.

– Active protection by MCI® Migratory Inhibitors.