Afzet Afvalstoffen als Secundaire grondstoffen: Milieuhygienische kwaliteit van secundaire bouwstoffen

The lack of landfill capacity for waste in the Netherlands has prompted a Dutch government policy strongly recommending the re-use of (bulky) waste in building and road construction works. To minimize pollution, secondary raw materials have to meet the standards for inorganic leaching and organic composition as set down in the General Administrative Order on Construction Materials (Soil and Surface Waters Protection) in the Netherlands. The RIVM has investigated the impact this Administrative Order will have on the applicability of potential secondary raw materials and products manufactured from these materials. The granular waste materials studied consist of various types of demolition wastes, bottom ash from municipal waste incinerators and powdered coal-fired power installations, phosphorus slag, steel slag, polluted dredging sludge, jet grit, different kinds of casting sand, mining stone and iron-containing sludge from drinking-water purification. Products studied were various types of cement concrete, asphalt cement and road-base materials. Whenever possible three or even more samples of the same waste were taken at different locations. The chemical composition and leaching behaviour were measured after pretreatment of the samples, the latter according to the standard leaching tests for the Netherlands, i.e. a column test for the granulates and a diffusion test for the products. When compared with the standards of the Order, the results for the granulate samples showed inconsistency in leaching and composition behaviour, i.e. some of the samples met the standards of the Order and so can be suitably applied as building materials, while others of the same granulate did not and so cannot be applied. The products showed fairly good consistency in their composition and leaching behaviour. With a few exceptions, all products from wastes were found suitable for application