SARA – The use of domestic clay as a sustainable building material

We are studying the possibilities of domestic clay.

Project duration

1.1.2023. – 31.12.2025

Source of funding

EAKR

Total funding

600000 €

Local excavation clays could be used in clay construction instead of being placed, for example, in urban landfill areas. Clay masses already deposited can also be used if the properties of the clays and their suitability as raw materials for new products are known.
The aim is to find new uses and thus promote the transition to a circular economy

In Finland, large volumes of potentially usable clay must be transferred and disposed of from construction and civil engineering projects. Clays in Southwestern Finland have been found challenging when used as construction materials, e.g., due to the highwater content and, in some places, the high sulfur content and acid production. There is little information on how excavated Finnish clays can be utilized as a part of the built environment. The utilization of these clay masses requires new ways of studying and treating the masses, and to this, the SARA project seeks to find new solutions. Adding more information allows for the broader use of clay.

If the clay could be used to make products without firing, it would save energy during the production stage. In addition, reducing natural raw materials and construction waste favors the use of clay in ecological construction. The goal is to develop and obtain unfired clay tiles and bricks suitable for construction use. The strength of unfired clay products can be improved by adding recycled materials, such as textile fibers, natural fibers, or fibrous waste streams from the forest industry.

Due to the large clay volumes to be excavated during construction, the clay should also be used in infrastructure projects. Surplus clay has been used, e.g., in the construction of noise barriers and to stabilize softer grounds to be built on. New larger-scale uses could be, for example, flood protection products or other prefabricated constructions.
In infrastructure construction, ashes and slags from local heat and combustion plants can also be used to substitute ordinary cement.

The measures of the SARA project will be implemented in five work packages. The circular economy and carbon neutrality are present throughout all work packages. The solutions are based on traditional and new insights.
The knowledge gained will be distributed in cooperation with companies, universities, and research institutes as the future clay construction model for using domestic clay as a building material.

The work packages together form a consistent whole on the availability, composition, development of clay products, and product testing of finished clay products. Piloting provides concrete evidence of the potential of clay construction. In addition, the work packages will provide more information on the clay products’ environmental impact and carbon footprint. The information can be used in companies and cities to support decision-making to reduce the carbon footprint. The project takes into account the needs of companies that use clay as raw materials, as well as clay builder education

The primary result of the project is to provide the target groups information on recycling and utilization of domestic clay. Companies can use the results of this project to develop new green growth businesses. The project will enable better reuse of material and waste streams alongside and as substitutes for original natural resources.