Review | The 2012 Olympics and Recycled Concrete

The 2012 Olympics and Recycled Concrete

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Introduction

Mention the phrase demolition to just about anyone and the image that promptly comes to mind is a vision of a building being blown up and collapsing to the ground. Plenty of people have claimed they would really like to press the button, to trigger the explosive units which will bring a disused structure to the ground. Most of the time the thing that comes down, must go up and now we are witnessing many unsightly buildings being demolished to help with making way for potential future development, normally together with a regeneration project.

For businesses who over several years have created their business surrounding the demolition of properties, the demolition industry has become considerably more reaching than simply blowing up unwanted buildings. Once the structure is demolished the tremendous task of site clearance starts and in a society where consideration of the environmental impacts are very high on many peoples agenda, the material remains coming from demolition ought to be separated for recycling purposes. This tends to include such resources as steel, wood, plastic, brickwork and concrete.

The majority of the materials tend to be bulked up and transferred into the appropriate recycling plants for reprocessing. Products such as bricks and concrete are generally crushed and converted into a recycled concrete aggregate product completely ready for reuse in the making of new highways or buildings. Increasingly though, by means of breakthroughs in technological development, derivatives including concrete to be recycled must meet a high standard for reuse in construction projects.

When crushed, the various grades of recycled aggregate will govern the future usage potential of the product. Larger sizes might be employed as decorative rockery products in landscaping while much finer, shingle like product can be utilised as a bedding for pipe laying or as a layer in highway construction. Through an ever-increasing amount of possibilities recognized for the reuse of recycled aggregate, the entire demolition and construction industry is making a substantial contribution to sustainable development.

Reasons For the Increased Concentration on Recycling from Construction and Demolition Projects

In 1996, UK Government added a duty on all waste materials going to landfill. The levy is paid out in addition to typical gate charges for waste being disposed in landfill and since its launch the cost has risen annually. When it was first introduced, the typical level of tax for general waste products going to landfill was �7 per tonne and �2 per tonne for inert materials. The tax should persuade commercial and industrial businesses and local authorities collecting from properties, to divert waste away from landfill for recycling. In April ’09, the standard rate of landfill tax grew to �40 per tonne and is also timetabled to rise each year by �8 per tonne until 2013. The reduced rate of tax incurred upon any inert materials going to landfill such as concrete and soils, has remained relatively steady in recent years and is presently at �2.50 per tonne.

Nevertheless, the weight factor alone of a bulk load of those inert products going directly to landfill will guarantee that the entire cost of disposal becomes horrendously expensive and so even in the demolition and construction sector, diverting waste from landfill is a top priority. The introduction of landfill tax has been a key driver in encouraging greater diversion of inert materials from landfill, to be used in sustainable development projects.

Having completed the initial step, demolition companies often bring crushing machinery on site to crush the brickwork and concrete remains.

The next time you see a demolition project in progress or go past just about any construction site during a build programme, it is obvious to see the amount of waste material being produced. If waste material is not in skips, heaps of rubble will probably be stacked high. The placing of rubble waste in skips has been a significant concern for waste contractors for several years. Having been an employee within the waste sector, I’ve seen skip lorries tipped backwards with the cab of the vehicle up in the air, a result of the sheer overloading of waste skips with construction site waste.

Each and every year, the united kingdom produces around 330 million tonnes of waste material and it is estimated that around 90 million tonnes of this is coming from building and demolition wastes. This figure has stayed reasonably steady since 2001. Approximately two thirds of this waste is normally recycled or reused in land reclamation or agricultural development projects. Ever since the later part of the 1990s there’s been a gradual increase in the volumes of construction waste being recycled and this has been helped by improvements in technology which have led to improved crushing solutions to make more common use of varying grades of recycled aggregates.

In recent years, the construction sector as a whole has worked hard to motivate construction site supervisors to put a larger emphasis upon recycling on site. This has triggered a rise in the recycling of all inert materials from site.

Before the introduction of the landfill tax almost all construction site waste material including bricks and concrete would be bulked up and moved to a landfill site for disposal. No deliberation was given to recycling. These day there are strict limitations across the sector, coupled with an increase in environmental awareness, and also the commercial benefits in ensuring that this type of waste is recycled. Addititionally there is increased recognition of the wide array of business opportunities to re-use recycled aggregates within the construction process on alternative construction projects or in environments such as landscaping or home and garden DIY. Following the demolition process, together the waste concrete, bricks, masonry etc will probably be transformed into a recycled concrete aggregate.

To recycle concrete aggregate to a high grade and resalable product, it has to be totally free of other debris such as wood, paper, card, steel and other general waste materials. The final product must comply with the specifications of British Standard BS 8500. The process of recycling the concrete can usually be achieved in one of two ways. Some demolition companies will locate a crushing system on the demolition site, whereas a lot of contractors will choose to move the waste to be recycled, back to their own premises for separation for recycling or re-use. On projects where demolition and new construction is to occur at the same site, the contractor is very likely to place a crushing appliance on site to escape incurring extra transport costs in taking the materials back to a sorting and crushing centre.

One Nottingham founded demolition contractor will be supplying 20-5mm recycled aggregate to the 2012 Olympic Village construction project.

The Growing Interest in Top Quality Recycled Aggregate

Before starting the crushing process, it needs to be determined what the end product is to be used for to make sure that the recycled aggregate is to match the required standards. There’s huge demand for recycled aggregate to be used during the construction process. As a product, recycled aggregate can be utilised for just about any type of concrete structural work, road surfacing or pipe laying project. Having passed through the crusher the chunks of aggregate can be separated by size. Bigger pieces may be retained as a cosmetic product for use in landscaping rockery projects, or they could be passed back through the crusher to be crushed to a reduced size. The small pieces of recycled aggregate may be suited to use as a gravel on new construction projects, road laying or driveways at home. The crushing units are now capable of achieving top 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 purchased 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.

The demand for top quality crushed aggregate is increasing. There are key standards in place which are targeted upon improving the recycled aggregate market. Through research and development, more widespread uses are being discovered for the use of recycled aggregate. No longer is concrete, just concrete. What we are talking about now are many different grades of recycled aggregate, which range from the large sections 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 highway construction, recycled aggregate is being used as bedding for pipe laying or foundation material prior to construction projects commencing. In achieving such high quality grades the 20-5mm recycled aggregate can be utilised as an aggregate base in highway building and the quality meets the standards required to allow its reuse in concrete production. The 20-5mm recycled aggregate is a very versatile product.

On the list of important criteria when using recycled aggregate is selecting the best specification for the task. For instance, when using 20-5mm coarse graded aggregate as a highway base, the thickness of the layer demanded needs to be determined to withstand traffic flows. Traffic flow on a motorway is going to be significantly different to that of a country road. One reason aggregate produced to a 20-5mm specification is used as a road base is that it assists good drainage. Once the recycled aggregate is installed, suitable layers of asphalt or concrete can be laid over it to form the road surface.

In recent years, in the UK we seem to have more bad weather than sunshine and therefore the selected aggregate must be able to endure variances in temperatures and conditions e.g. dampness for very long periods, torrential downpours, long dry spells. With its good waterflow and drainage qualities, the recycled 20-5mm product is the appropriate choice for a lot of sand and gravel applications including, pipe bedding, driveways and footpaths, landscaping, and also for use in ready mixed and precast concrete products. With its drainage qualities, 20-5mm recycled aggregate is a handy product.

Crushing machines are capable of producing good quality recycled concrete which can be used for a variety of purposes.

Recycled Aggregates and the 2012 Olympic games

In its bid for the 2012 Olympic Games, London placed sustainability as the focus of its bid. The bid team identified a major opportunity to boost awareness of climate change and the concerns which encircle it, and bring it to the World’s notice. With the eyes of the World observing, the Olympic Games provide an exceptional opportunity to convey key messages with regards to sustainability. Throughout the entire growth and development of the Olympic project, there is a responsibility to make 2012 the most sustainable Olympic Games ever held. This focus originated when planning the design and build programmes for the facilities and venues, the transport links and network, the hosting of the Games themselves and will end by leaving behind a long lasting heritage of a sustainable environment.

Ever since London was granted the Games, all companies associated with the development requirements, from the construction of the Olympic Arena, the Olympic Village and transport links to the venues have been focused upon ensuring the use wherever possible of sustainable materials. Throughout the entire Olympic build programme construction managers have worked hard to identify suitable sustainable materials for use in the build programme. At the end of the overall project we will see some clearly visible cases of the use of sustainable products.

At the same time 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 countless locations will not even consider how recycled aggregates are already specified as part of the overall construction project. But designers and specifiers of materials for use within the build programme will be comfortable in the knowledge that they have selected sustainable products including, the most suitable recycled concrete aggregates as part of the project. With its identified characteristics, let’s hope that somewhere in the global TV coverage the 20-5mm recycled aggregate gets a reference 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.

Summary

How times have developed in recent years for the demolition and construction market. Firms have been required to adapt to meet tough environmental specifications. As with almost any segment, new laws and legislation dictate the standards to which your business must aspire, if it is to achieve success.

Companies involved in the generation of recycled aggregate are no different. These are generally categorised 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 crucial 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 providing 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 road construction and driveways. The demolition and construction industry now places sustainability at the forefront of its future development projects.

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