22 Concrete Engineering International August 2015

Visual/Decorative Concrete

Evolving decorative concreteAt the recent Evolving Concrete show in London, delegates discussed the preconception about the use of concrete that stems from the 1960s and led to the material being considered grey, uninspiring and dull – the 1970s innovative concrete projects such as the Tricorn Shopping Centre in Portsmouth, UK where the author grew up, or the graffiti-covered concrete underpasses, suffering along with the rest of the ‘concrete jungle’.

John Grant, PICS, Newbury, UK

Two PICS projects at Disney in Hong Kong: Gift shop and above inset, Sleeping Beauty’s Castle.

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Concrete cannot be held responsible for the way it has been used. There are many successes in the use of decorative concrete, which produce aesthetically pleasing and structurally sound paving projects. Many of the techniques and finishes used in decorative concrete work are also transferable to the Wallcrete decorative walling system, which uses specialist decorative renders to achieve similar results on new or existing walls.

As the decorative concrete market has evolved and grown, designers and specifiers have become more familiar with, and confident at, specifying pattern-imprinted concrete together with a wider range of other specialist finishes. Within this evolving landscape, PICS has become involved in projects across varied applications and scope around the world.

In the preface to his 2012 book entitled Decorative & Innovative Use of Concrete(1), Graham True traces the use of concrete as a decorative and innovative material, using its unique properties. He states that, “designers from all over the world have been able to capitalise on the mouldability and final rigid stone-like form of concrete to furnish our environment with a variety of buildings and structures. Concrete does not have to be a dull material – any dullness comes from a lack of the users’ and designers’ imagination, combined with an inability to see the fundamental potential of the material”.

Guy CW Thompson, in his foreword to the same book, states that, “We are in an era when the visual potential of concrete as both an interior and exterior finish is being increasingly specified to support the wider drivers for the use of local materials, sustainability, material and energy efficiency, and cost certainty”.

There are many reasons to consider the use of locally produced decorative concrete, using finishes that offer excellent lifetime costs, durability and minimal maintenance when compared to alternative paving options – some are imported from some distance, thus increasing the environmental and transportation impact. Locally sourced ready-mixed concrete and aggregates are at the heart of most of the decorative concrete projects installed around the world.

Vietnam – 6 Degrees café.

Southport UK, seafront parade.

Visual/Decorative Concrete

24 Concrete Engineering International August 2015

Visual/Decorative Concrete

The evolution of design options, specialist tools and the specific skills required to carry out ever more creative decorative concrete installations has been clear to see over the past 40 years. Since 2008, The Concrete Society in the UK has judged hundreds of examples from around the world, of quality designed and implemented decorative concrete projects, through the annual PICS Golden Trowel photographic awards.

The level of expertise and creative design has been obvious to see, as the leading professional installers have increased their knowledge, understanding and practical skills base to undertake increasingly complicated and technically demanding paving projects.

Decorative concrete has been around in its current recognised forms for about 40 years, with much of the recognition of its durability and design flexibility coming from the work of pioneers such as Brad Boman in the 1950s and others in the USA, where the development of branded ‘ornamented’ and then pattern-imprinted concrete systems in particular spread the awareness and scale of contractor networks around the world.

In the UK, the technical specification and concrete mix design details are published in The Concrete Society guide to imprinted and decorative concrete(2), where it can be clearly seen that although the concrete surface may be transformed into pattern, texture and colour, the strength, durability and water:cement ratio follow standard concrete guidelines, to ensure that, while decorative, the structural integrity of the basic product is key.

The use of quality manufactured colour surface hardeners adds strength, abrasion resistance and increases the water:cement ratio at the concrete surface, thereby making the concrete harder-wearing, stronger and more resistant to staining and therefore much easier to maintain. Most decorative concrete surfaces are colour enhanced using a resin-based sealer, which adds protection and helps to minimise maintenance by making the surface easy to clean and reseal in later years. There are many examples

of quality pattern-imprinted concrete around the UK, which were installed 25 years ago – on petrol station forecourts as well as driveways – yet retain the colour, pattern and natural look of the original installation.

On a recent visit to the World of Concrete 2015 in Las Vegas, it was encouraging to see an increasing number of exhibitors and contractors attending, all with positive views on the future growth of business, and a real interest in the decorative techniques they offer. Many new approaches to installing decorative paving could be identified, as well as the growing market for the refurbishment of existing concrete surfaces.

Polished concrete, exposed aggregate, thin cementitious overlay options, as well as the widely used pattern-imprinted and stencil finishes, are much more common across the USA and Canada, and where North American clients and architects export their services around the globe. You can increasingly see the practical use of decorative concrete installed at Disney, McDonald’s, KFC and Starbucks to name a few, at their locations worldwide.

There are many examples of applications where readers may not have realised decorative concrete is used daily:Seafront promenade works – where durability, colour and strength to withstand the elements make concrete the obvious choice. But decorative concrete is also chosen to achieve unique designs, combining exposed aggregate including decorative glass and seeded aggregate, colour-hardened and timber-effect imprinted finishes.Public street works and transport infrastructure – where heavy construction methods use the strength and durability of reinforced concrete, and also add authenticity and recreation of local stone or cobble finishes to blend in with local environments; various forms of exposed aggregate and pattern-imprinted finishes have been used around Europe, including the replacement of an expensive hand-laid cobblestone road at the Rue de Luxembourg in Brussels and the Dublin light rail project.Rue de Luxembourg, Brussels.

Wellness Centre at the Maximus Resort Hotel, Brno Lake & Dam, Brno, Czech Republic.

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Visual/Decorative Concrete

Theme parks and visitor centres – projects range from Disney’s Hong Kong complex to Merlin Group’s Chessington World of Adventures, UK. Many high foot-traffic sites have tried other forms of paving, but choose to incorporate areas of decorative concrete including hand-created logos, features and creative themes.Zoos and wildlife parks – used for similar reasons to the theme park sector, but also used to mimic varying ground conditions and include features such as animal footprints, mud and sand effects and varying animal habitats.School and university buildings – where individuality and vibrant colours are designed as part of a themed paved area, walkways or gardens.Hotel and leisure resorts – there are many examples of the use of decorative concrete around European and worldwide holiday resorts, including projects in Holland, on Cape Verde, as well as the Mount Gay Rum Factory in Barbados.Petrol stations and service areas – Total, Shell, BP, Sainsbury’s and various independent petrol retailers have all used imprinted and decorative finishes alongside the standard brush-finished plain concrete forecourt areas. The performance of the decorative concrete can be clearly seen to match the high-strength and petrol-resisting standard mix designs required by civil and structural engineers.

Shopping developments – from the more recent ‘Kidzania’ project inside the Westfield Shopping Centre in west London, to projects the author has seen on his travels in Beirut, Manilla and Las Vegas, there is a massive range of decorative concrete. From polished concrete and acid-stained finishes, through to recreations of timber, quayside cobbles and vibrant children’s play areas, decorative concrete is built to last by experts in their field.Drive-thru restaurant chains – including McDonald’s, KFC, Burger King and Starbucks, and several farm shops. The levels of traffic flow through this type of application test the performance criteria of colour surface hardeners to the limit. There are many examples around the UK of these projects, which were installed over 15 years ago, yet considering the level of slow-moving traffic turning on them, they have performed excellently.

So across the world in various applications, decorative concrete has evolved into the paving of choice for

References1. TRUE, G.F. Decorative & Innovative Use of Concrete. Whittles Publishing,

Caithness, 320pp, April 2012.2. CONCRETE SOCIETY. Imprinted concrete – model installation clauses and

guidance notes. Camberley, 24pp, 2014.