Management of sulfate soil in respect of environmental issues and climate change

Important results from the project

The aim is to develop a methodology for a customised construction production based on a better assessment model that divides sulphide and sulphate soils into different classes based on suitability for reuse and suggest alternative methods to manage and use sulphide soil as construction materials. The objective of the project was to be based on a new classification system for sulphide soils enable: 1.Selective excavation and handling of sulphide-soils. 2.Enable increased reuse of sulphide soil on site. 3.Increase the possibility to assess and rate sulphides soil in the field.

Expected long term effects

The results of a series of lab and field experiments with different variants of sulphide and sulphate soils show how soil acidification potential and leaching properties vary according to sulphur content and how these sulphide compounds can be stabilised in order to be reused. The classification system has been used to classify sulphide soils along the first stretch of Norrbotniabanan, resulting in an assessment that approximately 40% are lacking acidifying properties, allowing easier handling and reduced transport. The results will be used to increase the re-use of sulphide soils.

Approach and implementation

Lab and field experiments were carried out within the framework of a doctoral thesis. The results were used to further develop a classification system for sulphide soils, which in turn allows a less restricted use. The industry, incl. environmental protection agencies have been interviewed to anchor the project. The classification system was also used to propose method that allows for selective excavation based on on-site assessment. The classification system has been used to assess sulphide and sulphate soils at the Norrbotnia rail road in order to reuse and reduce landfilling.