Tag Archive for: cement

vegetables

Can vegetables make concrete stronger?

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Engineers at Lancaster University are working with industrial partners at Cellucomp Ltd UK to research how concrete mixtures can be strengthened and made more environmentally friendly by adding ‘nano platelets’ extracted from the fibres of root vegetables.

The work, which is being supported with £195,000 by the EU’s Horizon 2020 funding, will strengthen findings from early tests that have demonstrated that concrete mixtures including nano platelets from sugar beet or carrot significantly improve the mechanical properties of concrete.

These vegetable-composite concretes were also found to out-perform all commercially available cement additives, such as graphene and carbon nanotubes and at a much lower cost.

The root vegetable nano platelets work to increase the amount of calcium silicate hydrate – the main substance that controls the performance of concrete, and stop any cracks that appear in the concrete.

By increasing the performance of concrete, smaller quantities are needed in construction.

The construction industry is urgently seeking ways in which to curb its carbon emissions. The production of ordinary Portland cement, one of the main ingredients for concrete, is very carbon intensive – its production accounts for 8% of total global co2 emissions. This is forecast to double in the next 30 years due to rising demand.

The proof-of-concept studies highlighted that adding the root vegetable nano platelets resulted in a saving of 40kg of ordinary Portland cement per cubic metre of concrete – which gives a saving of 40kg of CO2 for the same volume. This is because the greater strength of the root vegetable mixture means smaller sections of concrete are required in buildings.

Professor Mohamed Saafi from Lancaster University’s Engineering Department and lead researcher believes root vegetable concrete could go a long way to reducing construction carbon emissions.

Saafi said: “These novel cement nanocomposites are made by combining ordinary Portland cement with nano platelets extracted from waste root vegetables taken from the food industry.

“The composites are not only superior to current cement products in terms of mechanical and microstructure properties, but also use smaller amounts of cement. This significantly reduces both the energy consumption and CO2 emissions associated with cement manufacturing.”

The vegetable-based cementitious composites were also found to have a denser microstructure, which is important to prevent corrosion and increasing the lifespan of the materials.

The research project is also looking at adding very thin sheets made from vegetable nano platelets to existing concrete structures to reinforce their strength.

The two-year research project will investigate the science behind the results of the proof-of-concept studies to gain a fuller understanding of how the vegetable nano platelet fibres enhance the concrete mix. The researchers will also seek to optimise the concrete performance to help produce a mixture that can be used in the construction industry.

Cellucomp Ltd already uses fibres from root vegetables to manufacture more durable paints.

Dr Eric Whale from Cellucomp Ltd said: “We are excited to be continuing our collaboration with Professor Saafi and developing new applications for our materials, where we can bring environmental and performance benefits.”

Source: PBCtoday.co.uk

Graphene

Wonder material Graphene could revolutionise the construction industry

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Scientists say a greener, stronger and more durable concrete made using “wonder-material” graphene could revolutionise the construction industry.  

Graphene is a form of carbon first reliably produced at the University of Manchester by researchers in 2004, work which led to two Nobel prizes. It is made up of a single layer of carbon atoms in a hexagonal lattice. Its structure gives it important physical qualities, including efficient conductance of heat and electricity and unusual strength.

A research team at the University of Exeter, which includes Cast Consultancy’s Dimitar Dimov, has developed a technique which uses nanoengineering technology to incorporate graphene into traditional concrete production.

The researchers say the new composite material is more than twice as strong and four times more water resistant than existing concretes, and has been tested using British and European industry standards.

The graphene-reinforced concentre material also reduces the carbon footprint of conventional concrete production methods, according to the University of Exeter scientists. They add that the technique could pave the way for other nanomaterials to be incorporated into concrete.

Dimitar Dimov, lead author, who works at the University of Exeter engineering department and with construction consultancy Cast, said: “This research is important as it can be applied to large-scale manufacturing and construction. The industry has to be modernised by incorporating not only offsite manufacturing, but innovative new materials as well.

“Finding greener ways to build is a crucial step forward in reducing carbon emissions around the world and so help protect our environment as much as possible. It is the first step, but a crucial step in the right direction to make a more sustainable construction industry for the future.”

Professor Monica Craciun, co-author of the paper and also from Exeter’s engineering department, said: “This new composite material is an absolute game-changer in terms of reinforcing traditional concrete to meets these needs. Not only is it stronger and more durable, but it is also more resistant to water, making it uniquely suitable for construction in areas which require maintenance work and are difficult to be accessed.

“Yet perhaps more importantly, by including graphene we can reduce the amount of materials required to make concrete by around 50% – leading to a significant reduction of 446kg per tonne of the carbon emissions.”

The paper, Ultrahigh Performance nanoengineered Graphene-Concrete Composites for Multifunctional Applications, is published in the journal Advanced Functional Materials.

The research was supported by the UK’s Engineering and Physical Sciences Research Council.

Cement-making accounts for 6% of global carbon emissions, and manufacturers must make sharp reductions if the Paris climate goals are to be met, according to the Carbon Disclosure Project, in a recent study.

 

Source: Construction Manager / The Guardian