ABSOILS

Results and Benefits

RESULTS

The ABSOILS project has provided the stakeholders with new knowledge and guidance (European Guidelines) on the possibilities and methods of using earth construction materials based on various types of redundant, poor quality soils. The project has served as a successful example demonstrating environmental and economic benefits based on the utilisation of surplus soft soils for versatile engineering purposes.

Quality control activities, as well as the LCA studies carried out in the framework of the project provide the construction sector with reliable data on how such materials fulfil the technical and environmental criteria set for intended applications. The LCC study gives a proof of the economic competitiveness of the project pilot solutions.

The project has created an efficient and user-friendly system – the RMSS - that will allow for monitoring the current and future sources of surplus soils in order to plan their effective utilisation.

It is estimated that 4 million tons of surplus soils will be re-used in the capital region of Finland as the know-how on surplus soil utilisation possibilities improves all the time. As the utilization of surplus soils will eventually be an established method instead of landfilling, it is estimated that reduction of greenhouse gases (as CO2 equiv.) may be approximately 1,2 million tons CO2 yearly in Finland. Only in Helsinki, it is estimated that by surplus soil utilization, approximately 100-200 million euros can be saved every year.

ENVIRONMENTAL BENEFITS

The most important impact on the environmental problems targeted has been exerted by the implementation of the Piloting Actions.

The piloting actions (Arcada 2 and Jätkäsaari I and II) allowed for the stabilisation and utilisation of 142 000m3 of surplus soft clays and dredged sediments, and owing that the need for landfilling of these masses was minimised

The Pirttiranta pilot enabled the reuse of 4 000m3 of surplus clays

The Dog Park pilot allowed for the stabilisation of about 15 000 m3 of poor quality, soft clays. It gave the possibility to use fly ash and FGD as binder components, which is very important from the point of view of future permit applications of similar kind

The Jätkäsaari III pilot gives the possibility for utilisation of 90 000 m3 of dredged soft sediment for various future engineering applications, thus allowing for saving virgin materials that would have to be otherwise used for the construction of noise barriers in the city of Helsinki. Fly ash as binder was also tested at this site.

The so-far expected impact of the Honkasuo pilot is saving of 45 000 m3 of non-renewable materials.

Additionally, about 40 000 m3 of rock aggregate material was recovered in the Arcada 2 pilot site by processing and reusing. This, in turn, diminished the need for virgin rock material.

Stabilised masses from all the three stages of the Jätkäsaari pilot have been used for various construction purposes. Part of the masses were transported to other parts of Helsinki and utilised there, e.g. for the Vuosaari landfill cover or landscaping purposes in the Ida Aalberg park.

Due to the pilot applications, long-distance transportations to soil deposit sites were avoided, as well as the need to transport virgin rock material as replacement masses.

The impact of the pilots on the decrease of CO2 emissions was calculated during carrying out the LCA studies.

DISSEMINATION

The ABSOILS project team members have taken an active role in disseminating the information on the project and its objectives in discussions with various stakeholders both in Finland and internationally. Continual networking activities have increased the level of knowledge and raised the awareness of the importance of solving the issue of surplus soft soils. The project has received a very positive feedback from the representatives of the cities involved as a pioneering initiative in this field.