The ASH-CEM project (2016-2019), a collaboration between Ghent University, VITO (the Flemish Institute for Technological Research), CRH, Indaver and Orbix brought together scientific expertise and industrial knowledge to explore future applications of minerals recovered from incineration bottom ash, leftover from the combustion of municipal solid waste in Waste-to-Energy (WtE) facilities.

The project aimed at replacing virgin raw materials in cement applications with incineration bottom ash from the Indaver plants. The research resulted in two successful products: ASH-CEM, which uses bottom ash as partial cement substitution, and ASH-CARB which combines it with carbonation-based binders.

As part of the project, tests were performed on the structural behaviour of reinforced concrete beams made from 20% of the mineral fraction of processed bottom ash. It was concluded that both ASH-CEM and ASH-CARB can be used for making environmentally friendly products, e.g. road borders and prefabricated pavers, with properties that have been proven to be of equivalent performance to traditional concrete in terms of processability, strength and durability.

From the perspective of circular economy and climate ambitions, there are three main benefits of using incineration bottom ash in cement:

Saving raw materials;
Recovering WtE bottom ash to be used in valuable products;
Reducing CO2 emissions and other environmental impacts of construction products manufacturing.
The ASH-CEM project is a perfect example of how Waste-to-Energy fits into circular economy recovering both, materials and energy.

Project website: www.ash-cem.eu