Page 61 - Hub-4 Magazine ISsue 64

Quarrying
begs the question, why are we using structural grade aggregates to produce non-structural concrete? Surely we would use the appropriate material provided it gives us the appropriate outcome. In so many cases globally CDE customers are producing competitive concrete for these non- structural – but still high value – construction projects, with some applications successfully achieving beyond C45.
Determining whether a recycled concrete product is fit for purpose or not is dependent on how it is processed and its intended use.
Indeed, the Sheehan Group, one of the UK’s leading regional construction groups, has diverted over 750,000 tonnes of inert waste from landfill over the past seven years. It creates 20,000 building blocks a day from 100% recycled aggregates which follows a CE-certified process. Improved and advanced technology now sees the cement consumption reduced by 10% and Sheehan Group is still achieving the same high- quality specification and end product.
The group’s success shows that with the appropriate practices and the backing of the latest wet processing technology, high quality in-spec sand and aggregate products can be extracted from CD&E waste and returned to support new construction and infrastructure both consistently and competitively.
It is important to acknowledge, however, that poor processing practices impact uptake and acceptance in the usability of recycled materials. This is due to antiquated or less efficient technologies that fail to effectively remove contaminants, such as wood and plastic, from feedstock. The presence of these contaminants impacts upon the strength and structure of concrete.
Meeting growing demand
Soaring urbanisation presents a global challenge to meet the demands of the construction industry, and recycled materials are an effective solution when supported with the most appropriate technologies and practices.
It was anticipated that by 2050, over two-thirds of the world’s population (68%) would be living in urban settings, according to data from the United Nations , rising from around 55% of the population today. Combined with projections population growth, trends in urbanisation could add up to 2.5 billion to urban settings over the next 30 years. It remains to be seen how the pandemic will impact population growth, but it will undoubtedly weigh on future planning considerations for construction and infrastructure as a means to mitigate against the threat of disruption caused by future pandemics.
Economies have been hit hard by the crisis and as history has shown governments tend to respond by investing in infrastructure to kickstart the economy or in construction to reshore manufacturing facilities, which we’re already seeing UK and USA. This is where CDE technology will add value by maximising the quality, quantity and value of waste resources.
Currently an estimated 40-50 billion metric tonnes of primary aggregates – crushed rock, sand and gravel – is extracted every year , and GAIN, the Global Aggregates Information Network, in its global outlook to 2030, estimates aggregates production will rise to 60 billion tonnes per year over the next decade to support growth in urban populations.
CDE customer Velde Pukk AS plays a significant role in meeting the material demands in Stavanger, Norway, in the face of a construction boom. Utilising high-quality recycled aggregates and its on-site concrete batching plant, Velde Pukk AS supplies the construction industry with a CE-certified concrete from 100% recycled sand and aggregates. Likewise, AF Gruppen, also based in Norway, produces high-quality washed sands and aggregates which have also Norwegian standard certification.
Certified
It would be wrong to assume recycled sand and aggregates are only selected as alternatives to finite virgin materials in low strength and low value applications. Our process improves the quality of recycled sand and aggregates by removing foreign contaminants and classifying the output, resulting in higher-spec recycled products that can be used to produce concrete products.
Like so many of CDE’s pioneering customers leading the charge for a circular economy, and who have demonstrated the potential in CD&E waste by achieving certification for their recycled products, we need to recognise the strength and integrity of using recycled materials.
The recycling sector will continue to grow and it will gradually become more competitive. CDE is working with its customers to stay ahead of that curve and to adopt efficient and sustainable technologies that are future-ready. Those customers who have integrated wet processing technology into their plant are reaping the commercial advantages of superior end products and are facilitating sustainable construction by recovering high quality recycled materials.
For more information about CDE wet processing solutions, visit CDEGlobal.com
www.hub-4.com Sept/October 2020 - Issue 64
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