By-products and recycled materials in earth construction in Finland—an assessment of applicability

Over 6 million tonnes of industrial by-products and recycled materials are produced annually in Finland. Many of these materials are potentially suitable for earth construction. There is also an evident need for substitute materials for natural aggregates. The environmental aspects and prerequisites of utilisation were studied as a part of the Ecogeo Technology programme, which was funded by the National Technology Agency, Tekes. Guidance for the assessment of the environmental and technical applicability of industrial by-products for use in earth and road construction was developed. The guidance presents recommendations for the investigation of applicability, recommendations for environmental and technical criteria of the utilisation in earthworks and recommendations for production control procedures. As a consequence, national production control standards are prepared for reclaimed concrete and blast-furnace slag. As an example, a two-stage research project on the environmental properties of foundry sands is presented. The general environmental criteria for the utilisation of foundry sands in earth constructions were established. In addition, specific quality control procedures were developed for two selected foundries.