Concrete is one of the most widely used building materials in the world and also accounts for a large proportion of the waste generated in the construction industry. There is a clear desire from both industry and the authorities to increase the recycling of concrete for more sustainable use of resources. To achieve this, it is necessary to look at new and innovative methods for recycling concrete that are cost-effective and at the same time environmentally sustainable.
Two other problem waste in the world today are acid-forming rocks and waste from mining. These are rocks such as black shale and sulfur-containing mining waste that produce acid when exposed to air.
When concrete is crushed and exposed to water, the leaching water that comes out of the concrete will be affected by the chemistry of the concrete. The concrete is very alkaline and therefore has a high pH. The water that has filtered through the concrete will therefore also have a high pH. In this doctoral degree, Cathrine Eckbo will look at how the chemistry in leaching from concrete waste (with its high pH) can be used to stabilize acid-forming waste and thus reduce the negative environmental impact of this waste. The goal is to use one type of waste to treat another type of waste and thus contribute positively to the circular economy. Cathrine will also look at the potential spread of environmental toxins related to the recycling of crushed concrete as a construction material and how this changes over time.
Laboratory and field trials have been started and will be followed up in the future.