Geopolymer offers hope for low carbon constructors of future

Civil engineers have published a highly-significant paper to demonstrate how future buildings can be constructed with low-carbon geopolymers in place of concrete.

After water, concrete is the most widely used substance on the planet and its manufacture is responsible for 4-8% of total global CO2 emissions. It also sucks up almost a 10th of the world’s industrial water use and is associated with silicosis and other respiratory diseases.

Studies at Liverpool John Moores University demonstrate the potential of a substitute material which combines aluminium alloy with a novel geopolymer to construct the ‘skeleton’ of a building.

Cement-free, the geopolymer is made from industrial wastes and has already earned an award from the Institution of Civil Engineers.

Dr Michaela Gkantou, a senior lecturer in the School of Civil Engineering and Built Environment, said tests suggest the proposed composite cross-section could potentially be suitable for any type of multi-storey building.

“The paper lays out how an aluminium-geopolymer composite can be adopted with similar performance to a conventional composite but with more sustainable way,” said Michaela.

The LJMU team, which included Dr Monower Sadique and Dr Georgios Kamaris, carried out 24 tests on stub columns and 12 on beams. Four square hollow sections infilled with one-part geopolymer concrete were tested under uniform compression and under uniaxial bending. The same cross-sections were also tested as bare and infilled with ordinary Portland cement concrete.

They found the strength of the composite sections in both the stub columns and the beams were very similar between the two.

“Overall, we are seeing concrete gradually replaced in construction globally, first with steel-concrete composites and hopefully our novel aluminium-geopolymer composite.”

“Our objective now is to carry out tests on different types of structures and eventually complete a trial in a real-life building.”

The paper ‘Geopolymer concrete-filled aluminium alloy tubular cross-sections’ was published in the journal of the Institution of Structural Engineers, Structures, and authored by Michaela Gkantou (LJMU), Evangelia Georgantzia (Southampton - LJMU PhD Graduate 2022), Abdullah Kadhim (Al-Mustaqbal University College, Iraq - LJMU PhD Graduate 2021), George S. Kamaris (LJMU) and Monower Sadique (LJMU).