CD Laboratory for Waste-based geopolymer construction materials in the CO2-neutral circular economy

This CD Laboratory aims to bring together highly interdisciplinary expertise from waste, materials, environmental, geo- and civil engineering sciences to develop novel residue- and geopolymer-based building materials. Their sustainable production and high (bio)chemical resistance will contribute to more stable infrastructure facilities (and thus lower renovation costs) and at the same time take important steps towards CO2-neutral building material development.

So-called Portland cement is by far the most widely used binder in modern construction, but its susceptibility to corrosion favours damage caused by wind, weather and other environmental influences (such as the effect of (bio)chemically aggressive components of wastewater on wastewater transport systems and sewage treatment plants), which can lead to safety problems and high costs for the maintenance of structures: Worldwide, costs caused by corrosion are estimated at 2.5 trillion US dollars (or approx. 3.4 per cent of global gross domestic product), a large proportion of which relates to concrete as a building material.

On the other hand, the production of construction materials (which are essential for the renovation or new construction of infrastructure facilities damaged by corrosion) is responsible for just under a tenth (around 9 per cent) of all greenhouse gas emissions generated worldwide, which represents a massive environmental burden. And finally, the current handling of waste such as that from construction projects in Austria is not optimal in terms of either efficiency or environmental protection: at 54 million tonnes per year (or 76 percent of the total volume of waste), mineral waste not only represents the largest waste stream in the country, but almost 60 percent of it is also sent to landfill, resulting in the loss of valuable resources and large (landfill) areas.

In keeping with the interdisciplinary approach, this CD Laboratory is tackling all of these problems at the same time: Firstly, geopolymers generally have a higher resistance in (bio)chemically aggressive environments compared to Portland cement-based building materials, which in addition to greater stability also leads to a far lower financial burden, as 15-35 per cent of the aforementioned 2.5 trillion US dollars in costs due to corrosion could be saved through the use of more resistant materials and more effective condition surveys. Secondly, geopolymer building materials allow mineral waste, secondary raw materials and residual materials to be used as the main binder, which means that, in contrast to their use as cement additives, they can be used in far greater quantities, thus further reducing the burden on landfill sites and the environment. And thirdly, the global warming potential of residue-based geopolymers is 10 to 80 per cent lower than would be the case with building materials based on Portland cement, which is hugely beneficial for the environment.

This ingenious approach not only drastically reduces costs and safety risks, but is also rapidly working towards the CO2-neutral circular economy: This term stands for a regenerative system in which resource consumption and emissions are minimised by slowing down, closing and narrowing material and energy cycles, which represents an important step towards CO2-neutral building material development!