Geopolymers

“Geopolymers are fire-resistant, blast-resistant and acid-resistant, and could become the building and construction industry’s materials of the future.” CSIRO

BCRC’s team are at the leading edge of Geopolymer research and are perfectly placed to assist companies wanting to take a lead in the lucrative advanced materials market.

Management

Materials research and development is one of BCRC strengths. All of the Managing Consultants have been involved in major research and development projects. However, they also have extensive consulting and contracting experience which brings a balance and focus unusual to research organizations.

BCRC’s consultants are not only expert in Geopolymers they are able to provide advice on raw materials, production methods, quality control and marketing.

Research Approach

BCRC consultants are amongst the worlds leading experts in materials research (refer to our “People” brochure). Our consultants have had led multi million dollar research programmes and are trained to keep a clear outcomes based focus while maintaining a detailed analytical approach to assessment of possibilities that arise. Like managing a business in line with an agreed business plan and budget, BCRC’s engineers and scientists manage research programmes to follow the research programme and budget. However, this is not myopic. Proper pursuit of opportunities arising and avoidance of threats is essential. Like business, BCRC’s research uses the SWOT assessment method to ensure research and development provides the optimal outcome.

Geopolymers

Geopolymers maybe the materials of the future but they may also be the material of the past. Professor Davidovits, Director of the Geopolymer Institute in France, and the inventor of Geopolymers in the 1970’s, believes the pyramids were made from a re-agglomerated natural limestone in such a way that they can be classified as Geopolymers. There is significant support for this theory. Like the Pyramids Geopolymers are proving immensely durable.

Geopolymers are made by reacting an alkali activator with an alumino-silicate mineral such as fly ash. Different properties develop based on the mineral and activator chemistry and the temperature of reaction. BCRC’s chemists understand how to make different polymers and BCRC’s materials experts know where to source appropriate minerals.

Left – SEM of a Geopolymer showing the dense structure and absence of interfacial zones.

Geopolymers, or mineral polymers, are described as “the new material for the Third Millennium”. They are a mouldable ceramic that gives a hard, chemically stable, low shrinkage material. Unlike concrete it has exceptional sulphate and acid resistance and provides very high early age strengths. However, it can be produced using conventional concrete equipment.


 

Geopolymer Applications

Geopolymers were reinvented in the 1970’s but development work has remained of a confidential nature. It has been targeted at specific products for specific companies. Development costs were high but recouped by the mass production in items such as cars. But now development of products is a relatively low cost. Even moderate size companies can afford to become involved.

Sewage pipe: This is an ideal Geopolymer product as factory production will enable accelerated curing to give high throughput and eliminate the cost of pipe liners to protect against Hydrogen Sulphide induced acid attack.

Culverts: Culverts often transmit contaminated water leading to chemical attack. Geopolymers will provide a high degree of protection.

Precast facades: Geopolymers will enable lightweight durable panels to be used to reduce the load on the structure and have a double effect on cost reductions.

Precast Beams & Columns: There is an increasing trend to using precast beams and columns to reduce construction programmes and minimize on site labour. Geopolymers will enable quicker production and reduced member sizes due to the higher load capacities.

Precast Piles: Geopolymers are particularly suited to the use of precast piles in Acid Sulphate Soils, a major issue in NSW and Queensland.

Geopolymer Research

Class F fly ashes have been activated at high alkaline environments to obtain Geopolymer binders by BCRC’s Tony Song. The binder, bound with sand and aggregate, makes Geopolymer concrete. Some findings from a comprehensive series of experiments are listed below:

• Geopolymer concrete set at room temperature (23˚C) within 24 hours and achieved compressive strengths of at least 35MPa and 55Mpa at ages of 7d and 28d respectively. Hence, it is suitable for insitu applications such as linings and repairs.
• Geopolymer concrete can be quickly set at high temperature (70˚C). It developed at least 50MPa and 70MPa at ages of 1d and 28d respectively and hence it is suitable for prefabricated product manufacture.
• The resultant Geopolymer has an aluminosilicate network structure. Most alkalis are not free but are tied to this structure. Consequently, even though alkaline solution is used, there is very low risk of Alkali Aggregate Reaction and Delayed Ettringite Formation like conventional concrete.
• The ambient and accelerated cured Geopolymer concretes have been tested in a 10% sulphuric acid for an accelerated test of 8 weeks (see below) or in a 1% sulphuric acid for one and half years. Geopolymers were much superior than Portland cement concrete to sulphuric acid attack.

a) GP cement at 28 days

b) Geopolymer 71 at 56 days

c) Geopolymer 54 at 56 days

• This material becomes porous due to acid exposure, while at the same time it is stable in acidic environments. Hence while the material remains stable, the pH value drops and steel would corrode. BCRC’s team of corrosion scientist can advise on how to overcome corrosion issues using Cathodic Protection and corrosion resistant reinforcement.

Right – Micrograph of acid corroded Geopolymer showing the good interfacial zones.

 

Development Opportunities

BCRC’s team of experts are seeking opportunities to work with Australian Construction product companies to develop a range of products for immediate marketing as shown in the table to the below.

Partners Required For Geopolymer Product Development

Sewage Pipe Culverts Producers Vertically cast or roller compacted pipe manufacturers who cannot supply lined pipes are sought for development of an unlined Geoploymer pipe for use in situations where Hydrogen Sulphide leads to an acid attack risk.

Building Panel Precasters BCRC are looking for an existing innovative precaster who is prepared to fund the development suited to their current fabrication equipment and methods.

Precast Pile Producers A precast pile supplier is sought to fund development of a pile that is resistant to Acid Sulphate Soils. This would have wide ranging opportunities in the low lands of NSW and Queensland.

Repair Mortar Supplier BCRC a seeking funds to develop a Geopolymer repair mortar for use in a range of sever environments. Existing repair companies are the most likely candidates.

Reinforcement Suppliers BCRC is also seeking research funding to demonstrate Geopolymer ability to work with fibre reinforcement and galvanized and stainless steel reinforcement.

Geopolymer Team

The Geopolymer team comprises Bob Munn on raw materials, Marton Marosszeky on structural design, Mike Brungs on chemical engineering, Tian Chang on reinforcement corrosion control, Frank Papworth on business development and the team is headed by Tony Song as the Geopolymer technical expert.