Steel fibres akin to hairpins are also added to the mix, eliminating the need to assemble vast steel mesh grids. The process requires less materials and therefore less heat, which produces less CO₂ emissions.
"Without concrete, many of the world's most impressive buildings and structures – such as Australia’s Sydney Opera House and the Hoover Dam in Las Vegas – wouldn't exist", said Dr Abbas.
"However, the impact it has on our planet is telling and the construction industry must find a way to reduce concrete's carbon footprint while keeping the benefits of a cheap and durable building material," he continued.
The low-carbon concrete mix, produced a 40 per cent smaller carbon footprint compared to traditional concrete. The costs and emissions of construction are lower as a result, and the final product is just as strong as a traditional breakwater.
"Using less to build more may worry coastal communities which live in fear of tsunamis, as sustainable breakwaters are likely to be thinner, smaller and curved instead of straight," said Dr Jayaratne.
"However just because something is bigger, it does not always mean it is stronger. We have a responsibility to ensure that our defences against climate change are not indirectly causing it.
"Our low-carbon structures are just as strong and show that the world can adapt to the effects of climate change without making it worse," he concluded.
Read the full paper, 'Reducing embodied carbon dioxide of structural concrete with lightweight aggregate,' published in the Proceedings of the Institution of Civil Engineers – Engineering Sustainability.
Read Dr Jayaratne’s paper proposing to manufacture breakwaters with the low-carbon concrete in, 'Stability of Breakwater Armor Units against Tsunami Attacks,' published Journal of Waterway, Port, Coastal, and Ocean Engineering (available here).