KUCHING: Researchers at Swinburne University of Technology Sarawak Campus are excited about the potential of creating a greener variety of cement using locally-sourced industrial by-products.
Swinburne Sarawak Research Centre for Sustainable Technologies acting director Dr Dominic Ong and PhD student Leong Hsiao Yun are using fly ash from coal combustion to make a material called geopolymer, which can be used to replace ordinary Portland cement in concrete.
According to Ong, geopolymer cement is greener and more sustainable as it utilises industrial by-products and can help reduce the carbon footprint.
“For every one tonne of cement produced, one tonne of carbon dioxide is released into the environment. Geopolymer can be a suitable alternative because it makes use of resource material from the combustion of coal.
“If we could reuse the resource material, which is fly ash, we can create a more sustainable construction material. What we intend to do here is to explore ways that we can use more of this material,” he told StarMetro in an interview.
Ong explained that concrete consists of water, cement and aggregates such as gravel, with cement acting as the binder.
He said the current practice was to add fly ash to concrete as an additive to strengthen its resistance to acid attack.
“Is there a possibility that we use 100% fly ash and no cement? That is what we are researching.
“Fly ash is inert in its natural form, so we need alkaline chemicals to activate it. Once the fly ash becomes active it would serve exactly the same function as cement.
“With our lab now established, we can carry out our research work, such as mixing the chemicals with the fly ash and aggregates and test the strength of the concrete. Now we want to up the tempo and prove that there’s so much potential in fly ash geopolymer.”
Ong said the research project, which is about three years old, had shown reasonable success with three papers published in respected international journals so far.
“This is an immediate achievement and testimony that Sarawak fly ash has the quality to be considered for use as geopolymer, as a green sustainable material.”
Leong said the fly ash used in the research came from a local power plant.
“If we use it to produce geopolymer, in future we may have the potential to use it as an alternative to cement. So looking into the future, if we have the chance to use it, we can try to reduce carbon dioxide emission and greenhouse gases,” she said.
Besides using the fly ash to make geopolymer concrete, she has also been researching its potential for brick production by mixing it with soil.
Ong said the next step in the geopolymer research was to look into the potential of other by-products such as manganese from industries in the Sarawak Corridor of Renewable Energy.
“Over a short period of time here we have shown that fly ash has the potential to be a constituent of a greener material, so definitely there will be potential from other by-products.
“Being in research, it’s our role to create awareness on what is available and what can be done to make the world a greener place. This is our little effort to contribute back to society,” he said.