The 2012 Olympics and Recycled Concrete

Introduction

Mention the phrase demolition to just about anyone and the scene that instantly comes to mind is often a vision of a structure being blown up and collapsing to the ground. Many people have claimed they would really like to push the button, to trigger the explosive units which bring a disused building to the ground. On many occasions the thing that comes down, must go up and we are witnessing many old properties being razed to help with making way for future development, frequently within a regeneration project.

For businesses who over many years have created their business around the demolition of buildings, the demolition sector has become far more reaching than simply blowing up outdated buildings. As soon as the property is demolished the huge task of site clearance begins and in a modern world where consideration of the environmental effects are high on a good number of peoples agenda, the material remains as a result of demolition have to be sorted for recycling applications. This can include such resources as steel, wood, plastic, brickwork and concrete.

A lot of the materials are bulked up and sent into the appropriate recycling plants for reprocessing. Resources such as bricks and concrete are generally crushed and converted into a recycled concrete aggregate substance available for reuse in the construction of new highways or buildings. More and more though, through advances in technological development, residues such as concrete to be recycled have to meet a very high specification for reuse in construction projects.

When crushed, the assorted sizes of recycled aggregate will determine the likely usage potential of the product. Large sizes could possibly be used as decorative rockery products in landscaping whilst much finer, almost shingle like product can be used to provide a bedding for pipe laying or as a layer in street construction. With an increasing amount of options recognized for the reuse of recycled aggregate, the whole demolition and construction industry is building a significant contribution to sustainable development.

Reasons Behind the Increased Focus on Recycling from Construction and Demolition Projects

In 1996, UK Government imposed a duty on all wastes going to landfill. The levy is paid on top of regular gate rates for waste being disposed in landfill and since its launch the charge has risen annually. When it was first introduced, the common level of tax for general waste materials going to landfill was �7 per tonne and �2 per tonne for inert products. The tax was designed to inspire commercial and industrial companies and local authorities collecting from households, to divert waste away from landfill for recycling. In April '09, the standard rate of landfill tax grew to �40 per tonne and is timetabled to increase annually by �8 per tonne until 2013. The lower rate of duty incurred upon any inert materials going to landfill for example concrete and soils, has remained fairly stable recently and is currently at �2.50 per tonne.

Even so, the weight of a bulk load of inert products going direct to landfill will guarantee that the full cost of disposal becomes very expensive and so even in the demolition and construction arena, diverting waste from landfill is a top priority.

The materials which remain after the use of the demolition equipment may be changed into a variety of reusable products for use in other construction projects.

Next time you see a demolition project in progress or go past any construction site during a build programme, it's obvious to see the amount of waste being produced. If waste is not in skips, piles of rubble will probably be stacked high. The placing of brick waste materials in skips has been a significant issue for waste contractors for several years. Having worked within the waste industry, I have seen skip lorries tipped backwards with the cab of the vehicle up in the air, a result of the gross overloading of waste skips with building site waste.

Each year, the uk produces close to 330 million tonnes of waste and it is estimated that around 90 million tonnes of this is from building and demolition wastes. This figure has stayed fairly constant since 2001. Close to two thirds of this waste is generally recycled or reused in land reclamation or agricultural improvement projects. Ever since the late 1990s there's been a gradual increase in the quantities of construction waste being recycled and this has been aided by advances in technology which have led to improved crushing products to make more common use of various grades of recycled aggregates.

In the past few years, the construction industry in general has worked hard to encourage construction site supervisors to put a greater focus upon recycling on site. This has triggered a growth in the recycling of all inert materials from site.

Before the introduction of the landfill tax almost all construction site waste including bricks and concrete was bulked up and transferred to a landfill site for disposal. No regard was given to recycling. Nowadays there are strict regulations across the sector, coupled with an increase in environmental consciousness, as well as the commercial rewards in ensuring that this type of waste is recycled. There is also increased recognition of the large choice of potential opportunities to use recycled aggregates within the construction process on future construction projects or in fields such as landscaping or home and garden Do-it-yourself. Following the demolition process, together the waste concrete, bricks, masonry etc will probably be transformed into a recycled concrete aggregate. Recycling of aggregates has become a common process for demolition contractors.

To recycle concrete aggregate to a high standard and resalable product, it needs to be totally free of other impurities such as wood, paper, card, steel and other general waste materials. The final product also needs to comply with the requirements of British Standard BS 8500. The process of recycling the concrete can typically be achieved in one of two ways. Some demolition companies will install a crushing machine on the demolition site, whereas various contractors will prefer to carry the waste to be recycled, to their own premises for segregation for recycling or re-use. On projects where demolition and new construction is to occur at the same location, the contractor is likely to locate a crushing unit on site to escape incurring extra transport costs in taking the materials to a sorting and crushing facility. There is now very complex crushing equipment on the market to reduce concrete to a very fine specification.

One Nottingham centred demolition contractor have been supplying 20-5mm recycled aggregate to the 2012 Olympic Village construction project.

The Increasing Interest in High Quality Recycled Aggregate

Before commencing the crushing procedure, it needs to be determined what the end product will be used for to make sure the recycled aggregate is to match the required standards. There's huge requirement for recycled concrete aggregate to be used back in the construction process. As a product, recycled concrete aggregate can be utilised for just about any kind of concrete structural work, road surfacing or pipe laying project. Having passed through the crusher the pieces of aggregate can be separated by size. Bigger pieces may be retained as a cosmetic product to be used in garden rockery projects, or they might be passed back through the crusher to be crushed to a smaller size. The smaller pieces of recycled aggregate could be suitable for use as a gravel on new construction projects, road laying or driveways at home. The crushing machines are now capable of achieving good quality small aggregate grades such as the production of a 20-5mm gravel which can be bagged and used in the garden at home or bought in bulk as part of projects involving new concrete production. The advances in technology mean that the recycling of aggregates for other uses such as a simple gravel product or for use in concrete products has greatly reduced the need to dig quarries to mine for gravel. Recycled aggregates have become a versatile reusable product and has eliminated the need for large volumes of a good material to be disposed of in landfill and therefore offer significant environmental benefits.

The interest in top quality crushed aggregate is increasing. There's key standards in position that are concentrated upon improving the recycled concrete aggregate industry. Through research and improvement, more widespread applications are now being identified for the employment of recycled aggregate. No more is concrete, just concrete. What we are talking about now are many different grades of recycled aggregate, ranging from the large chunks of aggregate to very specific 6f2 recycled concrete which can be used as a sub-base material for construction jobs, or 20-5mm recycled aggregate, which is a gravel and can be utilised in road construction or at home on driveways. As well as being used as a mix for road construction, recycled aggregate is being used as bedding for pipe laying or footing material prior to construction projects starting. In achieving such high quality grades the 20-5mm recycled aggregate can be used as an aggregate base in road construction and the quality meets the specifications required to allow its reuse in concrete production. The 20-5mm recycled aggregate is a very versatile product.

One of several important considerations when using recycled aggregate is selecting the correct specification for your task. By way of example, when using 20-5mm coarse graded aggregate as a highway foundation, the depth of the layer needed needs to be determined to stand up to traffic flows. Traffic flow on a motorway will be significantly different to that of a country road. One good reason aggregate produced to a 20-5mm specification is used as a road base is that it supports good drainage. Once the recycled aggregate is laid, suitable layers of asphalt or concrete can be laid above it to create the road surface.

In recent years, in the UK we appear to have more rain than hot sunshine and for that reason the selected aggregate must be able to withstand variances in temperatures and conditions e.g. dampness for long periods, torrential downpours, long dry spells. With its good waterflow and drainage qualities, the recycled 20-5mm product could be the perfect choice for many sand and gravel applications including, pipe bedding, driveways and footpaths, landscaping, plus for use in ready mixed and precast concrete products.

In matters as complex as demolition it is advised to retain a specialist company conversant with BREEAM and other demolition legislation www.eastmidlandsdemolition.co.uk is one such company that comes highly recommended.

Recycled Aggregates and the 2012 Olympic games

In its bid for the 2012 Olympic Games, London set sustainability as the focal point of its bid. The bid team recognized a significant opportunity to raise awareness of climate change and the concerns that encircle it, and bring it to the World's attention. With the eyes of the World observing, the Olympic Games provide a unique opportunity to convey important messages regarding sustainability. Throughout the entire growth and development of the Olympics project, there exists a determination to make 2012 by far the most sustainable Olympic Games ever held. This focus originated when setting up the development and build programmes for the facilities and venues, the transport links and network, the hosting of the Games themselves and will end by leaving a long lasting heritage of a sustainable healthy environment.

Since London was awarded the Games, all partners involved with the development requirements, from the building of the Olympic Stadium, the Olympic Village and transportation links between the venues have been focused upon ensuring the use wherever possible of sustainable resources. Across the entire Olympic build programme construction managers have worked hard to locate suitable sustainable materials for use in the build programme. By the end of the whole project we will see some clearly visible examples of the use of sustainable products.

Similarly there will be many more that are much less visible, and furthermore, many which will be not visible at all. One of those products which visitors to the games and its many venues will not even consider how recycled aggregates have been used as part of the overall construction project. However designers and specifiers of materials to be used in the build programme will be comfortable in the knowledge that they have selected sustainable products which include, the most suitable recycled concrete aggregates as part of the project. With its identified characteristics, let us hope that somewhere in the global Television coverage the 20-5mm recycled aggregate gets a mention somewhere, somehow. Imagine being asked to supply recycled aggregate which meets a very specific 20-5mm clean material specification, to help build the 2012 Olympic Village.

Conclusion

How times have changed recently for the demolition and construction industry. Businesses have been required to adapt to meet challenging environmental conditions. As with just about any market, new regulations and legislation dictate the benchmarks to which your business must aspire, if it is to be successful.

Firms engaged in the manufacturing of recycled aggregate are no different. These are classed as processed materials and must conform to a particular product specification which can be used in the construction process. The standard BS8500-2 offers a full specification for the uses of recycled concrete aggregates in concrete, although with such a vast range of recycled aggregates an all encompassing specification for the use of these aggregates is yet to be determined. The most important thing is that the industry does not stand still and wait for the specifications to be finalised. The versatility of recycled aggregates means that demolition contractors operating crushing plants are seeking to identify markets through which to sell their recycled products. The advances in crusher technology and machinery has seen a big increase in the options now available in supplying large chunks of recycled aggregate for landscape gardening use in rockeries, down to a gravel type 20-5mm recycled aggregate with its good drainage qualities to be used in highway construction and driveways.