MELBOURNE, Oct. 27 (Xinhua) -- Researchers in Australia have developed low-carbon concrete roof tiles made from coal ash and recycled glass waste, cutting carbon emissions by 13 percent compared with conventional concrete tiles.

A large-scale trial of sustainable roof tiles by Australia's Royal Melbourne Institute of Technology (RMIT) and Bristile Roofing produced hundreds of the concrete tiles incorporating ash waste from coal-fired power stations and glass, two challenging waste streams, delivering both environmental and engineering benefits, a RMIT press release said Monday.

The finished product by Bristile Roofing's Melbourne factory was lighter and more fire resistant, while meeting Australian standards for strength and durability, the press release said.

The project avoids energy-intensive processing and effectively replaces virgin materials by replacing 10 percent of cement with harvested pond ash and 10 percent of river sand with unwashed glass waste, a total of 20 percent virgin material replacement, it said.

"We not only reduce waste going to landfill, but also produce an improved concrete product with enhanced fire resistance, a valuable feature for roofing in Australia's climate," said RMIT researcher Chamila Gunasekara, the project lead.

Australia produces about 12 million tonnes of coal ash and over 1.3 million tonnes of glass waste annually, with more than 400 million tonnes of coal ash stored in large settling ponds and more than half of glass waste ending up in landfills, according to the study.

The research, published in Sustainable Materials and Technologies and The International Journal of Life Cycle Assessment, also extends to prototype concrete bricks using 35 percent waste materials, showing a potential 18 percent drop in carbon emissions, it said.

Additional collaborations with local councils and commercial partners are now underway to trial the roof tiles in real-world settings, it added. ■