Advanced concrete repair mortars and protective coatings extend lifetime of landmark structure
Background
The iconic Venetian Bridge in Clacton was built in the Venetian style in 1914. Spanning ‘Pier Gap’, it provides an impressive entrance for visitors to Clacton Pier. 2014 marked the centenary of this landmark structure but the destructive effects of 100 years of chloride attack became evident when a small section of concrete broke away, resulting in the erection of support scaffolding to temporarily make the bridge safe.
Tendring District Council made the restoration of the Venetian Bridge a corporate priority and £355,000 was allocated for its renovation. A number of different options were considered, including demolition, and Flexcrete products were chosen in order to extend the lifetime of the bridge and retain it as a landmark focal point for visitors to the area.
The Perfect Solution for Aggressive Coastal Locations
Prestec UK removed all of the defective concrete from the soffits, spandrel and transverse beams, as well as preparing the whole structure using high pressure water jetting. The chosen concrete repair and protection system was designed in consultation with Richard Jackson Consulting Engineers to withstand the aggressive coastal conditions and persistent chloride attack. An essential part of the specification was compliance of all Flexcrete products with BS EN 1504, the pan European standard for concrete repair.
Following the removal of the defective concrete and finishes, Prestec UK applied Steel Reinforcement Protector 841 to the rebars to provide them with a corrosion preventative flexible coating prior to the application of Monomix – a high strength, shrinkage compensated, waterproof cementitious mortar which can be applied by trowel up to thicknesses of 80mm in a single application. Monolevel FC – an engineering quality fairing coat – was then used to fill minor blow holes and defects and provide a fair faced finish. Bond-Prime was applied to the complete surface of the bridge before the application of two coats of Monodex Smooth, a highly advanced, waterborne, elastomeric coating which is ideal for the decorative protection of structures and buildings. It provides excellent protection against carbonation, chloride penetration and water ingress, yet allows damp substrates to breathe.
Monodex Smooth is a single component, water-based coating so it is user-friendly and cures without the release of strong odour or hazardous solvents. It is ultra-fast drying, enabling two coat applications on the same day and it can be applied all year round. Available in a range of standard and special colours, magnolia was chosen for this project. Even in harsh climatic conditions, Monodex Smooth demonstrates excellent colour retention and strong UV resistance.
Client
Tendring District Council
Contractor
Prestec UK
Engineer
Richard Jackson Engineering Consultants
Venetian Bridge - Project Profile