Reducing Concrete With Bubbles... And Carrots
Over the past few weeks, the SOLID team have been taking an in-depth look at concrete and what changes can be made to reduce concrete’s carbon emissions. With concrete production accounting for 7% of global carbon emissions, three times that of the aviation industry, it is vital that changes are made. Since our 1% Better Every Day Concrete topic was launched last month we have looked at how viable carbon neutral concrete is as a building alternative and how concrete sensors can reduce construction time on site, saving both time and money.
Bubbles to Help Reduce Concrete Use
Today’s post looks at another format to reduce the amount of concrete used on site. Contractors working on high-rise buildings have identified a way to reduce their concrete usage drastically by using plastic ‘bubbles’ filled with air. The plastic bubbles, which are made from recycled plastic, create air pockets between slabs of concrete. This omits the need for solid reinforced concrete.
The technology, developed by Cobiax is believed to reduce consumption of natural resources and reduce CO2 emissions by up to 20%. The Cobiax team recognise that whilst we are required to be carbon neutral by 2050 the only current economical option for large-scale and commercial building is to build using concrete. However, with cement production being so energy intensive, an alternative solution needed to be implemented to allow for concrete to be used, but without such a harsh impact on the environment. Cobiax implements ‘Optimised X-zones’ into their products – these are structural elements built-in to form spherical or ellipsoid hollow spaces which ensure there is enough load-bearing ability without any additional sheer reinforcement. Not only is this technology innovative, but it is also working… and well.
On average, implementing a Cobiax system into a large-scale building project will save approximately 35% concrete per building. To put that into context Cobiax have reduced CO2 emissions by 180,000 tonnes since the year 2000. Their projects include the Microsoft German Headquarters in Munich, which saved 3,708 tonnes of concrete equating to 312 tonnes of CO2 and the United Nations Campus in Bonn which saved 600 tonnes of concrete and 50 tonnes of CO2. *
Eco-Friendly Concrete Alternatives
Whilst there is the call to put an end to concrete use worldwide, we are not there yet. Eco-friendly alternatives are generally only viable on small scale projects. Therefore, efforts to reduce concrete usage are generally more realistic in the short term. Cobiax focus on systems that replace large amounts of concrete while others are researching how to strengthen concrete to mitigate the need to use so much.
Researchers from various UK universities are investing in concrete strengthening techniques. The University of Exeter have been working to insert atomically thin shards of graphene into the water being used in mixing concrete. Graphene is an allotrope of carbon, which is arranged in a hexagon lattice pattern using nano-engineering. Tests show that this combination is twice as strong as regular concrete and four times as water resistant. *
Carrots Can Help Strengthen Concrete
Scientists at the University of Lancaster are using similar technologies, however, rather than inserting Graphene into the mix they have been inserting fibres… from carrots! Concrete’s strength is primarily composed of calcium silicate hydrate and by inserting fibres from carrots and other root vegetables scientists are adding more of this calcium silicate hydrate to the mix. Initial tests are indicating that this option is strengthening concrete better than any other concrete composite, and it's cheaper too.*
The SOLID team will continue to research ground-breaking sustainable options for construction as part of our 1% Better Every Day mission and we look forward to implementing some of these into our own projects where we can.
*https://www.cobiax.com/intl/en/sustainable/
*https://www.dezeen.com/2018/08/09/carrots-concrete-stronger-lancaster-university-technology/