Even the most durable concrete built to the highest standards needs repair and protection to help extend its design life. This is clearly demonstrated by a concrete repair and coating project recently carried out at Teikyo School, an independent boarding school for Japanese students in Wexham, Buckinghamshire.
Set in 20 acres of rural ground, the Buckinghamshire site will be familiar with many of those with a long background in the concrete industry as it was formerly the primary training centre for the Cement and Concrete Association (C&CA). Known as the Fulmer Grange Conference and Training Centre and remembered by many with nostalgia for the food and camaraderie, this residential facility was constructed in 1967 and had 160 single bedrooms across two blocks, lecture and seminar rooms, plus a suite of laboratories for demonstrations and hands-on experience. At the time, the C&CA offered a total of 100 courses ranging from one to five days’ duration and by 1968 the six-week Advanced Concrete Technology course had been launched.
When the Fulmer Grange Conference and Training Centre was originally constructed, it represented the peak of excellence in concrete construction. Comprising two identical four-storey residential blocks, the concrete was made in white cement and was largely board-marked, except for the use of exposed concrete blockwork, the grey blocks contrasting with white concrete.
The effect throughout was somewhat Scandinavian and due to the repetition involved in the construction of the two blocks, an industrialised method of construction was used – an adapted form of the Bison Wall Frame system. Each block was constructed on a 10ft module, with pre-cast concrete loadbearing cross-walls supporting precast concrete slabs. The architects were Alex Gordon and Partners; Veryard and Partners were the structural engineers and Howard Farrow Construction the main contractors.
Although 100,000 people had attended C&CA courses at Fulmer Grange by 1985, the demand for residential courses declined and the Training Centre was sadly closed in 1987. The Teikyo University Group purchased the premises and Teikyo School was founded in 1989 after being accredited by the Ministry of Education in Japan. It is now a boarding school for male and female students aged between 15-18 years and all students originate from Japan. The site is shared with the International School of Creative Arts.
Although the former C&CA Training Centre was built to the highest standards of concrete durability and it was originally perceived that no coating works would be required, significant remedial work was needed in 2015. As a result of concrete spalling on pre-cast panels on the two blocks due to the harmful effects of carbonation over the years, extensive concrete repairs were required, as well as coating of the external walls for decorative and anti-carbonation protection.
As repairs needed to be carried out vertically as well as horizontally, a lightweight repair material was required. Monolite, an ultra-high build, low density, cementitious mortar, was subsequently specified. Able to be applied by trowel up to 100mm in a single application, it is ideal for the cosmetic repair, rendering and profiling of concrete and is suitable for overhead, vertical and horizontal applications. With excellent low sag properties, Monolite is supplied as a single pack product and only requires the addition of clean water on-site. As it has a water-based formulation, it is safe to use, non-hazardous and virtually odourless. With ultra-low VOC levels, it can be safely applied in sensitive or confined areas, so there was no disruption to Teikyo School students during the refurbishment work.
Following the concrete repairs, a protective, decorative coating was required for application to the complete external façade to enhance the appearance of the two blocks whilst providing anti-carbonation protection. Monodex Smooth, a highly advanced, waterborne, elastomeric coating, was specified. With high diffusion resistance to carbon dioxide, it provides excellent protection from the effects of carbonation, chloride penetration and water ingress, yet allows damp substrates to breathe. Monodex Smooth provides such high weatherproof protection that it has been proven worldwide even in typhoon conditions and incorporates an active biocide which prevents the growth of mould and fungi on its surface. Due to its elastomeric properties, it is able to withstand thermal and structural movement without cracking or flaking and maintains an attractive appearance throughout its long lifespan.
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. Even in harsh climatic conditions, Monodex Smooth demonstrates excellent colour retention and strong UV resistance and like Monolite, it is CE marked in accordance with the demands of BS EN 1504, the pan European standard for concrete repair. Monodex Smooth is available in both special and standard colours, of which magnolia was chosen for this project. The main contractor for the renovation project was Takenaka Construction, and product application was carried out by TC&D Construction.
“I personally went on several residential courses at the Fulmer Grange Conference and Training Centre, including my Advanced Concrete Technology Course in 1984 and this project has certainly brought back many fond memories of my time there. Perhaps most memorable were the desserts which usually came with lashings of custard. Despite being delicious and totally lump free, it made my friend homesick as his wife made very lumpy custard. I also remember the long summer evenings playing croquet on the manicured lawns and the rude awakening every morning when a member of staff would knock on each individual door to make sure everyone was awake – mobile phones had not been invented by then!”
The concrete repair and coating work has transformed the external appearance of the accommodation blocks and will provide Teikyo School with excellent waterproof and anti-carbonation protection for many years before any maintenance is required. This nostalgic project demonstrates that even the most well designed concrete buildings and infrastructure need some form of repair and protection in order to protect them from the elements and extend their design life.