Waste and building materials: what type of articles should be submitted to Waste Management?

Fig. 1. Relationship between waste and raw materials in the production and use of building materials; the lines illustrating areas of interest for Waste Management are emphasized. An ever-increasing number of papers focusing on the use of waste as an alternative material in the production of building materials is being submitted to Waste Management. Indeed, the wide variety of waste components available meets the requirements of an extensive range of construction materials. Wastes taken into account for the above purpose include fractions separated from municipal solid waste streams (e.g. glass, paper, plastic), residues from thermal treatment (fly ash, bottom ash, exhausted sands from fluidised bed incinerators) and special wastes (scrap tyres, C & D waste, WEEE, sludges) at times classified as hazardous waste. The characteristics of the above-listed wastes indicate their suitability to carry out specific functions in the preparation of various products applied in the construction of roads, bridges, buildings and other civil engineering works. Therefore, varying degrees of these wastes may be mixed with cement, sand, tar, granulates and clay to obtain cement, mortar, bitumen, bricks, geopolymers, lightweight materials, etc. This new sector is undoubtedly of interest to our journal in view of the numerous aspects relating to waste management and protection of the environment. The recycling of waste in construction materials implies a significant reduction in amounts destined to disposal by landfilling, enhances the achievement of recycling rates established by law, leads to a reduction in the use of non-renewable resources, promotes closure of the material cycle with immobilization of elements (particularly heavy metals) that would otherwise have been available to the environment and produces a positive outcome on climate change both by acting as a carbon sink and through a lower consumption of fossil fuels. Additionally, in several socio-geographical situations, conventional building materials may prove to be too expensive and not sufficient to face the worldwide growing need for housing development. Accordingly, the use of waste as alternative material may help to face the above shortage. A diagram illustrating the relationship between wastes and raw materials used in the production of building materials is presented in Fig. 1. Suitable wastes may be derived from the selection and treatment of municipal solid wastes or special wastes, or from industrial processes (coal ash, foundry sand, blast furnace slags, etc.). The mixing of wastes with inert fractions to produce construction materials should be undertaken to improve functionality rather to merely dilute wastes. Only in this way will an effective waste recycling be achieved. The materials produced must necessarily comply with technical construction (resistance, compression, etc.) and environmental