Project Location: Tywyn Coastal Defence Scheme, Wales

Posted on in the category Concrete Repair, Enhanced Durability for Concrete & Steel, Coastal Structures, Corrosion Protection.

Marine Mortar S Repairs Concrete Sea Defence Wall

Repair of Deteriorated Reinforced Concrete Sea Defence Wall.


The £7.6m Tywyn coastal defence scheme was developed by Atkins in order to protect the picturesque sea-front properties from the threat of flooding.

Since construction in the 1930’s, the sea defences had regularly suffered attack from storms, with significant impact damage from rock resulting in the inevitable need for structural reinstatement. With marine mammals such as dolphins, porpoises and seals often seen from Tywyn seafront, the repairs had to be conducted on time with minimal environmental impact.

The Solution

The specification called for the use of high performance mortars for hand application and for pourable repairs. After the use of Steel Reinforcement Protector 841 on the cleaned rebars, Marine Mortar S was hand applied to the prepared concrete wall as it has early resistance to tidal wash-out. To re-profile the crest of the wall, specially shaped formwork was installed into which Monopour PG & PC6 were inserted via a letterbox entry to match the existing shape. Marine Mortar S is a high strength mortar which is mixed with water and applied directly to saturated concrete.


Gwynned County Council


Concrete Repair Technology Ltd on behalf of Jones Bros (Ruthin) Co Ltd