Adomast Manufacturing Ltd, the construction chemicals specialist, has supplied its eco-friendly concrete release emulsion for use in the construction of a new Wastewater Treatment Works at North Queensferry on the Forth Estuary, north-west of Edinburgh.
The project, managed by Scottish Water Solutions, involved the upgrading and refurbishment of the treatment works which was nearing the end of its useful life and needed to be replaced.
Work is being carried out by Balfour Beatty Civil Engineering on a ‘postage stamp’ sized site that sits on the banks of the Forth and is overshadowed by the massive structure of the Forth Rail Bridge.
Balfour Beatty demolished the old works, which provided primary treatment and served a population of around 1600, and have built a temporary treatment facility to maintain the sewage treatment process throughout the construction period.
The new works is being built in the same position as the old installation and includes the construction of reinforced concrete settlement tanks and concrete structures to house GRP septic tanks. The concrete specification for the project is very specific to minimise the corrosive effects of saline and hydrogen sulphide.
Balfour Beatty’s site engineer, Brian Coman explains: “The original works, built in the early 1980’s, was constructed with a regular concrete mix which didn't have the same resistance to chemical attack. Severe corrosion of the concrete structure was the main reason for replacing the original treatment works.”
The North Queensferry site is bounded by two Sites of Special Scientific Interest (SSSI): to the east is the shoreline of the Firth of Forth and to the north is Carlingnose reserve that contains areas of herb-rich grassland, a scarce and declining habitat.
The choice of Adomast’s SAFELEASE for concrete formwork was an obvious one for such an environmentally sensitive site. SAFELEASE uses the latest water soluble polymer technology to produce a concrete release agent that is virtually odourless and has low VOC content (Volatile Organic Compounds).
SAFELEASE is readily biodegradable, carries WRAS approval for use on potable water projects, and is resistant to wash-off by rain. A highly effective alternative to mineral oil-based products, SAFELEASE is an excellent release agent that is non-staining and provides a high quality surface finish.
Other products from Adomast were employed on the project included: SAFETARD LIQUID, a surface retarder for application to the top face of freshly placed concrete and SAFETARD GEL, a surface retarder for formwork.