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The 2012 Olympics and Recycled Concrete

Introduction

Mention the word demolition to almost anyone and the scene that promptly comes up is usually a vision of a building being blown up and collapsing to the floor. Plenty of people have said that they would love to push the button, to detonate the explosive systems which will bring a disused structure to the ground. Often what comes down, must go up and we are witnessing many old properties being demolished to make way for future development, generally within a regeneration project.

For organizations that over many years have created their business surrounding the demolition of properties, the demolition arena has become far more reaching than just demolishing old and unwanted buildings. As soon as the building is demolished the massive task of site clearance starts and in a society where consideration of the environmental effects are ever increasing on most peoples agenda, the material remains from demolition must be separated for recycling purposes. This will likely include such resources as steel, wood, plastic, brickwork and concrete.

Almost all of the materials can be bulked up and transferred into the appropriate recycling plants for reprocessing. Materials such as bricks and concrete can be crushed and converted into a recycled concrete aggregate product completely ready for reuse in the construction of new roadways or buildings. More and more though, via advancements in technological development, derivatives including rubble to be recycled must meet a high specification for reuse in construction projects.

When crushed, the different sizes of recycled aggregate will govern the future usage potential of the product. Larger sizes could be used as cosmetic rockery products in gardening whilst much finer, almost shingle like product can be utilised to provide a bedding for pipe laying or as a layer in road construction. Through an ever-increasing number of options recognized for the reuse of recycled aggregate, the entire demolition and construction industry is making a substantial contribution to sustainable development. Following demolition of a site, many demolition contractors have expanded their service offering to include site clearance services.

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

In 1996, UK Government added a duty on all waste items going to landfill. The tax is paid out on top of regular gate charges for waste being disposed in landfill and since its introduction the price has increased on an annual basis. When first introduced, the common rate of tax for general waste materials being sent to landfill was �7 per tonne and �2 per tonne for inert products. The duty was created to inspire commercial and industrial companies and local authorities collecting from households, to divert waste away from landfill for recycling. In April 2009, the standard level of landfill duty increased to �40 per tonne and is timetabled to rise annually by �8 per tonne until 2013. The reduced rate of tax charged upon any inert materials going to landfill including concrete and soils, has remained comparatively steady in recent years and is currently at �2.50 per tonne.

Even so, the weight of a bulk load of those inert products going direct to landfill will ensure that the entire cost of disposal becomes horrendously expensive and so even in the demolition and construction market, diverting waste from landfill is a top priority.

New development projects often begin with the decision to bring in controlled demolition machinery contractors who can demolish an old building first.

The next time you see a demolition project in progress or go past almost any construction site during a build programme, it is obvious to see the amount of waste being generated. If waste material is not in skips, heaps of rubble will be stacked high. The placing of brick waste materials in skips has been a serious problem for waste contractors for several years. I have worked in the waste industry, I have seen skip lorries tipped backwards with the cab of the vehicle up in the air, because of the gross overloading of waste skips with construction site waste.

Each year, the united kingdom generates around 330 million tonnes of waste and it is estimated that around 90 million tonnes of this is coming from construction and demolition wastes. This figure has remained relatively constant since 2001. About two thirds of this waste is normally recycled or reused in land reclamation or agricultural development projects. Since the later part of the 1990s there’s been a steady increase in the volumes of construction waste being recycled and this has been aided by developments in technology which have led to improved crushing products to make more common use of different specifications of recycled aggregates. There’s been a genuine focus upon the United Kingdom construction industry to encourage greater recycling of waste materials on site.

In the past few years, the construction sector in general has worked hard to persuade construction project managers to put a larger focus upon recycling on site. This has resulted in a growth in the recycling of all inert materials from site.

Before the introduction of the landfill duty almost all construction site waste including bricks and concrete was bulked up and transferred to a landfill site for disposal. No particular attention was given to recycling. Nowadays there are strict restrictions across the sector, in conjunction with an increase in environmental awareness, and also the commercial advantages in making sure that this sort of waste is now recycled. Addititionally there is better recognition of the large choice of potential business opportunities to re-use recycled aggregates in the construction process on new construction projects or in fields such as landscaping or home and garden DIY. Following the demolition process, together the waste concrete, bricks, masonry etc will 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 grade and resalable product, it needs to be entirely free of other impurities such as wood, paper, card, steel and other general waste materials. The end product also needs to conform to the requirements of British Standard BS 8500. The task of recycling the concrete can usually be achieved in one of two ways. Some demolition contractors will locate a crushing system on the demolition site, whereas some contractors will choose to move the waste to be recycled, to their premises for sorting for recycling or re-use. On projects where demolition and new construction is to occur at the same location, the contractor is very likely to place a crushing machine on site to avoid incurring added transportation costs in taking the material back to a sorting and crushing centre. There is now very advanced crushing equipment existing to reduce concrete to a very fine specification.

Approval from the local authority is going to be required before site clearance contractors starting the task of demolishing a building.

The Growing Demand for 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 the recycled aggregate is to match the necessary standards. There’s huge demand for recycled aggregate to be used back in the construction process. As a product, recycled aggregate can be used for virtually any form of concrete structural function, road surfacing or pipe laying project. Having passed through the crusher the pieces of aggregate can be sorted by size. Bigger pieces can be retained as a decorative product for use in landscaping rockery projects, or they may be passed back through the crusher to be crushed to a smaller size. The smaller bits of recycled aggregate might be suitable for use as a gravel on new construction projects, road laying or driveways at home. The crushing units 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 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 high quality crushed aggregate is ever-increasing. There’s key standards in position which are focused upon improving the recycled aggregate market. By means of research and development, more widespread uses are now being discovered for the employment of recycled aggregate. No longer is concrete, just concrete. What we are talking about now a variety of different grades of recycled aggregate, which range from the large chunks of aggregate to very precise 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 used in road construction or at home on driveways. As well as being employed as a mix for highway construction, recycled aggregate is being used as bedding for pipe laying or footing material prior to construction projects starting. In achieving such top quality grades the 20-5mm recycled aggregate can be utilised as an aggregate base in road construction and the quality meets the standards required to allow its reuse in concrete production. The 20-5mm recycled aggregate is a very versatile product.

One of several important criteria when using recycled aggregate is selecting the correct specification for your task. For instance, when using 20-5mm coarse graded aggregate as a road foundation, the depth of the layer demanded will have to be determined to tolerate 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 waterflow and drainage. Once the recycled aggregate is laid, appropriate layers of asphalt or concrete can be laid over it to construct the road surface.

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

It is always better to employ a specialist company with knowledge of the latest building demolition legislation, such as BREEAM, click here to see one such company.

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 big opportunity to raise awareness of climate change and the challenges that encircle it, and bring it to the Globe’s attention. With the eyes of the World observing, the Olympics present an exceptional chance to communicate important points concerning sustainability. Through the entire growth and development of the Olympic project, there is a commitment to make 2012 the most sustainable Olympics ever held. This focus began when setting up the design and build programmes for the amenities and venues, the transportation links and system, the hosting of the Games themselves and will conclude by leaving behind a long lasting legacy of a sustainable environment.

Ever since London was awarded the Games, all companies associated with the development requirements, from the building of the Olympic Arena, the Olympic Village and transportation links between the venues have been encouraged upon ensuring the use wherever possible of sustainable resources. Throughout the entire Olympic build programme developers have worked hard to identify suitable sustainable materials for use in the build programme. At the end of the whole project there will be 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 venues will not even consider how recycled aggregates are specified as part of the overall construction project. But developers and specifiers of resources for use in the build programme will be comfortable in the knowledge that they have selected sustainable products which include, the most appropriate recycled concrete aggregates as part of the project. With its recognized characteristics, let us hope that somewhere in the worldwide 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 in recent years in the demolition and construction market. Companies have needed to change to meet demanding environmental standards. As with just about any sector, new laws and legislation determine the standards to which your business must aspire, if it is to achieve success.

Businesses involved in the generation of recycled aggregate are not any 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 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 for use 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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