Repair and strengthening works on the spiral ramp of the San Giorgio Bridge in Genoa

An access ramp connects the San Giorgio Bridge to the A7 Motorway on the Eastern side. This spiral viaduct provides access for traffic coming from the bridge onto the motorway that runs towards the lower Piedmont and Lombardy regions. Repair and strengthening work was carried out on all parts of the viaduct and various Mapei products were used for repairing, strengthening and waterproofing its elements.

CONCRETE REPAIR AND STRENGTHENING
MAPEFER 1K cementitious mortar was applied on the steel reinforcement to prevent corrosion and MAPEGROUT EASY FLOW one component, fibre-reinforced thixotropic mortar was used to repair the concrete structures. In those areas where a higher level of ductility was required, the team decided to opt for MAPEGROUT EASY FLOW GF, hi-flow cementitious mortar reinforced with inorganic fibres.
The hi-flow, fibre-reinforced, compensated-shrinkage mortars MAPEGROUT HI-FLOW B2 and MAPEGROUT GF BETONCINO B1 were used for repairing concrete.
MAPELASTIC GUARD, a two-component, elastic cementitious mortar, was used for waterproofing the concrete surfaces.

The following products also came into use: MAPEGROUT LM2K, thixotropic, fibre-reinforced, cementitious mortar for concrete repair; ADESILEXPG1, thixotropic epoxy adhesive for structural bonding; EPOJET, superfluid epoxy resin for injections and anchoring, and MAPEFIX EP 585, pure epoxy resin-based chemical anchor for structural loads.

WATERPROOFING THE DECK
The deck of the access ramp was waterproofed by applying PURTOP 400 M SYSTEM DECK, a complete waterproofing system which is CE marked in compliance with ETAG033 guidelines. 

PRIMER SN two component, fillerized epoxy primer was used to treat the concrete substrate, before broadcasting QUARTZ0.5. Then, PURTOP 400 M hybrid polyurea membrane was applied to waterproof the surfaces, followed by the application of PURTOP PRIMER BLACK, a solvent-based primer that improves adhesion of asphalt surfaces waterproofed with products fromthe PURTOP line.

FINISHING THE SURFACES
The surfaces were finished off by applying MAPECOAT E23, an epoxy primer used to protect concrete before applying polyurethane finishing products, MAPECOAT PU33, a polyurethane resin-based, flexible coating for protecting concrete, MALECH, an acrylic, water-based primer used to even out surfaces and promote adhesion, and ELASTOCOLOR PAINT, an elastomeric paint for the crack bridging protection of internal andexternal surfaces, with permanent elasticity and a high level of resistance to chemicals.