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Scientific paper validates the performance of PureGRAPH® graphene concrete additives

Posted By Graphene Council, Monday, August 10, 2020
A new paper from leading universities has confirmed the importance of high aspect ratio graphene platelets for the enhancement of compressive strength in cement mortars and concrete. The research led by the University of Adelaide used high performing PureGRAPH® additives supplied by First Graphene Ltd. for the investigation. Improvements of 34.3% in compressive strength and 38.6% in flexural strength were recorded at very low dosage levels, equivalent to 0.02%w/w in mortar or 0.01%w/w in concrete.

The researchers observed that performance increased as the aspect ratio of the pristine graphene (PRG) particles increased, indicating that the PureGRAPH® products manufactured by First Graphene’s proprietary electrochemical process are ideal candidates for enhancing cement performance.

The researchers conclude “The results from this study indicate that Pristine Graphene is not only a promising additive in practical application for building materials to improve the current drawbacks of cement composites, but also a feasible option to support the reduction of cement mass used in cement composites, which could reduce the CO2 footprint and amount of CO2 emission into the atmosphere.”

Tags:  First Graphene  Graphene  Pristine Graphene  University of Adelaide 

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Concrete results: First Graphene and University of Adelaide use graphene to produce high-strength cement

Posted By Graphene Council, Wednesday, March 4, 2020
Graphene additives from First Graphene have been shown to increase the strength of cement mortar significantly, enabling the construction of lighter and more environmentally friendly buildings and civil engineering structures.

In a paper published in the journal Construction and Building Materials, researchers at the University of Adelaide report that the addition of just small amounts of First Graphene’s PureGRAPH® products to cement can increase the building material’s compressive and tensile strengths by 34% and 27%, respectively.

These findings are significant given the impact that the production of cement has on the environment. Cement is the source of about 8% of the world's carbon dioxide (CO2) emissions, according to the UK's Royal Institute of International Affairs. If the cement industry were a country, it would be the third largest emitter in the world, behind China and the US. It contributes more CO2 than aviation fuel (2.5%) and is not far behind the global agriculture business (12%)[1].

Chief technology officer, at First Graphene, Dr. Andy Goodwin, says: “By increasing the strength of concrete with PureGRAPH®, we can use less material to produce a structure with the necessary mechanical properties. If it was to be adopted across the construction industry, we believe that the use of PureGRAPH® could cut global CO2 emissions by approximately 2.5%.”

The University of Adelaide researchers have tested a number of graphene-enhanced mortars, and they have found that a mixture containing 0.07%-by-weight ultra-large size (56 ± 12 µm) pristine PureGRAPH® possesses optimal mechanical properties. This enhancement is attributed to improvements in the degree to which the cement paste hydrates, which results in the production of more calcium silicate hydrate gel. Adhesive bonds are also created as a result of friction generated between the sheets of PureGRAPH® and the cement gels, strengthening the cement matrix composites and impeding the development of cracks within them.

These benefits are achieved with little-to-no modification to the mortar production process. Dr. Andy Goodwin says: “The PureGRAPH® concrete additive was introduced as an admixture directly in the water used for preparing the cement mortar. No additional mixing equipment or processing steps were required.”

First Graphene has developed an electrochemical process that enables the tonnage-scale manufacture of pristine, high-aspect-ratio platelets of graphene with a typical thickness of 5-10 carbon layers. Dr. Andy Goodwin concludes: “The initial results obtained by the University of Adelaide researchers using our graphene are extremely encouraging. We look forward to the next stage in our partnership, as we continue to develop leaner, greener concrete materials.”

Tags:  Andy Goodwin  construction  First Graphene  Graphene  University of Adelaide 

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Concrete Graphene Applications, Literally!

Posted By Terrance Barkan, Wednesday, January 10, 2018

Advanced materials company, First Graphene Limited (ASX: FGR) is working with the University of Adelaide (UoA) on graphene for industrial building products.

Graphene in Concrete

Experiments have been conducted on the use of graphene oxide (GO) being added to concrete to improve both compressive and tensile strength. However the hydrophilic and high resistivity nature of GO limits its applications in things such as ‘smart’ cement.

Due to the high aspect ratio of nano-reinforcements such as graphene and carbon nanotubes, they have the ability to arrest crack propagation in concrete (by controlling the nano-sized cracks before they form micro-sized cracks) and hence greatly improve peak toughness, making them more effective than even conventional steel bar or fibre reinforcements.

Premium Concrete Products – Smart Cement

Ultra-High Performance Concrete (UHPC) operates at such a high-performance level that it competes with steel rather than regular concrete grades. Advantages include lower lead times compared to steel. UHPC can cost in excess of $500/tonne, with enhancements such as micro-reinforcements further increasing the price.

Due to the immense importance of compression strength and other factors such as blast, ballistic and earthquake resistance, additive premiums can be significant. UHPC is over an order of magnitude more expensive than regular concrete, but in an environment where material usage and weight are such essential considerations, it can actually be cheaper to use the more expensive grades in the long run, especially factoring in the reduced maintenance costs incurred by UHPC.

The UoA is testing FGR graphene, with the aim of making “smart cement” with conductive graphene flakes which may;

i. address the concerns of cracking and corrosion, and
ii. provide conductivity for better monitoring the health of concrete structures.

The first test results indicate the addition of just 0.03% standard graphene by weight is the optimal quantity of graphene from the test conducted to date, showing a 22 - 23 % increase in compressive and tensile strength, respectively. The addition of more standard graphene does not increase or decrease the strength of the concrete material when compared to the control in this test work.

Promising Results with Favourable Economics

This initial work has yielded very promising results with very small amounts of FGR graphene required to greatly increase the strength of the materials. Determining the optimum mixing methods and concentration to develop a consistent material will be the key to further developing this project.

The focus of the next stage of the work will be trialling other concentrations of graphene in concrete, specifically loading at 0.01% and 0.1% graphene, and optimisation of the mixing procedures. New methods of incorporating graphene into the concrete mixture will also be trialled.

The graphene provided by FGR will have a range of aspect ratios (smaller sheet sizes) and will be tested over the full range of concentrations. It is anticipated this material will better disperse within the concrete mixture and therefore provide further mechanical strength improvements.

The concrete admixtures market is estimated to be worth US$18.10bn by 2020. The drivers identified for the concrete admixtures demand are growing infrastructure requirements in developing economies, improving economics of construction, and shifting preferences of population towards urbanisation.


Tags:  Concrete  First Graphene  Graphene  University of Adelaide 

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