The 2012 Olympics and Recycled Concrete
By randomguy. Filed in Random |
Introduction
Mention the phrase demolition to just about anyone and the image that instantly comes to mind is usually a vision of a building being blown up and collapsing to the floor. A lot of people have stated they would love to press the button, to detonate the explosive units which will bring a disused structure to the floor. On most occasions the thing that comes down, must go up and now we are witnessing many old structures being taken down to help with making way for potential future development, normally as part of a regeneration project.
For businesses who over many years have developed their business within the demolition of structures, the demolition industry is now much more reaching than simply demolishing outdated buildings. Once the property is demolished the tremendous task of site clearance begins and in a world where consideration of the environmental impacts are ever increasing on many peoples agenda, the material residues provided by demolition ought to be separated for recycling reasons. This will likely include such materials as steel, wood, plastic, brickwork and concrete.
Most of the materials are bulked up and transported to appropriate recycling plants for reprocessing. Resources such as bricks and concrete are generally crushed and converted into a recycled concrete aggregate product ready for reuse in the construction of new roads or structures. Increasingly though, through advancements 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 varied sizes of recycled aggregate will govern the likely usage potential of the product. Large sizes could possibly be employed as decorative rockery products in gardening whilst much finer, almost shingle like product may be used as a bedding for pipe laying or as a layer in highway construction. With an ever-increasing variety of possibilities recognized for the reuse of recycled aggregate, the whole demolition and construction market 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 levy on all waste items going to landfill. The duty is paid on top of typical gate fees for waste materials being disposed in landfill and since its introduction the charge has risen annually. When first introduced, the standard rate of tax for general wastes being sent to landfill was �7 per tonne and �2 per tonne for inert products. The duty should inspire commercial and industrial companies and local authorities collecting from households, to divert waste away from landfill for recycling. In April '09, the typical rate of landfill duty rose to �40 per tonne and is scheduled to rise annually by �8 per tonne until 2013. The reduced level of duty charged upon any inert materials going to landfill for example concrete and soils, has stayed comparatively steady recently and is currently at �2.50 per tonne.
However, the weight of a bulk load of inert products going straight to landfill will ensure that the whole cost of disposal becomes very expensive and so even in the demolition and construction sector, diverting waste from landfill is a 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 specific step, demolition companies frequently bring crushing machinery on site to crush the brickwork and concrete remains.
Next time you see a demolition project in progress or go past just about any construction site during a build programme, it's clear to see the amount of waste materials being produced. If waste material is not in skips, heaps of rubble will probably be stacked high. The placing of concrete waste material in skips has been a major issue for waste companies for many years. Having been an employee within the waste industry, I have seen skip lorries tipped backwards with the cab of the vehicle up in the air, due to the sheer overloading of waste skips with building site waste.
Each and every year, the united kingdom generates around 330 million tonnes of waste material and it is estimated that around 90 million tonnes of this is from construction and demolition wastes. This number has remained relatively constant since 2001. Around two thirds of this waste is usually recycled or reused in land reclamation or agricultural development projects. Ever since the later part of the 1990s there's been a steady rise in the quantities of construction waste material being recycled and this has been aided by developments in technology which have resulted in improved crushing products to create more widespread use of different specifications of recycled aggregates.
In the past few years, the construction sector as a whole has worked hard to motivate construction project managers to place a greater emphasis upon recycling on site. This has led to a growth in the recycling of inert materials from site.
Before the introduction of the landfill duty almost all construction site waste material including bricks and concrete would be bulked up and transported to a landfill site for disposal. No thought was given to recycling. These day there are strict regulations across the sector, as well as an increase in environmental focus, as well as the commercial advantages in making sure that this sort of waste is recycled. Addititionally there is better recognition of the vast array of opportunities to re-use recycled aggregates in 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 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 has to be completely free from other impurities such as wood, paper, card, steel and other general waste materials. The end product must also comply with the requirements of British Standard BS 8500. The process of recycling the concrete can normally be achieved in one of two ways. Some demolition contractors will locate a crushing system on the demolition site, whereas a lot of contractors will opt to carry the waste to be recycled, to their premises for separation for recycling or re-use. On projects where demolition and new construction is to take place at the same location, the contractor is very likely to place a crushing machine on site to escape incurring extra transport costs in taking the material back to a sorting and crushing centre.
For many demolition projects the main building demolition contractor should complete good assessment of the challenges involved.
The Growing Interest in High Quality Recycled Aggregate
Before starting the crushing process, it needs to be determined what the end product is to be used for to ensure that the recycled aggregate is to satisfy the required standards. There is huge requirement for recycled aggregate to be used during the construction process. As a product, recycled aggregate can be utilised for virtually any kind of concrete structural work, road surfacing or pipe laying project. Having passed through the crusher the chunks of aggregate will be sorted by size. Bigger pieces can be retained as a cosmetic product to use in garden rockery projects, or they might be passed back through the crusher to be crushed to a reduced size. The small bits of recycled aggregate could be suited to use as a gravel on new construction projects, road laying or driveways at home. The crushing devices 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 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 need for good quality crushed aggregate is increasing. There are key standards in place which are focused upon improving the recycled 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 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 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 high quality grades the 20-5mm recycled aggregate can be used as an aggregate base in highway 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 the important considerations when you use recycled aggregate is choosing the correct specification for the task. For example, when using 20-5mm coarse graded aggregate as a highway foundation, the thickness of the layer needed will have 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 reason aggregate produced to a 20-5mm specification is used as a road base is that it helps good drainage. Once the recycled aggregate is laid, appropriate 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 hot sunshine and therefore the selected aggregate must have the capacity to endure variances in temperature and conditions e.g. dampness for very long periods, torrential downpours, long dry spells. With its good drainage qualities, the recycled 20-5mm product is the ideal choice for many 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 useful product.
It is always better to employ a specialist company with knowledge of the latest building demolition legislation, one such campany can be found by clicking here.
Recycled Aggregates and the 2012 Olympics
In its bid for the 2012 Olympic Games, London set sustainability as the focal point of its bid. The bid team identified a significant opportunity to raise awareness of climate change and the challenges which encircle it, and bring it to the Globe's notice. With the eyes of the Entire world observing, the Olympic Games present a unique opportunity to communicate key points concerning sustainability. During the whole development of the Olympic project, there is a determination to make 2012 by far the most sustainable Olympics ever held. This focus originated when preparing the development and build programmes for the facilities and venues, the transport links and network, the hosting of the Games themselves and will conclude by leaving behind a long lasting heritage of a sustainable healthy environment.
Ever since London was granted the Games, all suppliers associated with the development specifications, from the building of the Olympic Arena, the Olympic Village and transport links to the venues have been encouraged upon guaranteeing the use wherever possible of sustainable resources. Across the entire Olympic build programme developers have worked hard to identify practical sustainable materials for use in the build programme. By the end of the overall project we will see some clearly obvious examples 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 many venues won't even think about how recycled aggregates have been employed as part of the overall construction project. However developers and specifiers of resources to be used within the build programme will be comfortable in the knowledge that they have selected sustainable products including, the most appropriate recycled concrete aggregates as part of the project. With its identified characteristics, let us hope that somewhere in the worldwide TV coverage the 20-5mm recycled aggregate gets a reference somewhere, somehow.
Summary
How times have developed recently for the demolition and construction business. Firms have been required to change to meet challenging green requirements. As with virtually any market, new laws and legislation determine the standards to which your company must aspire, if it is to achieve success.
Businesses engaged in the generation of recycled aggregate are not any different. These are 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 main 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 offering 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.