ABSTRACT
The release of substances from construction materials into the soil and groundwater is a growing concern that has been addressed in the framework of the European Regulation on construction materials. This issue is particularly obvious when waste is used as a component of construction materials. The environmental assessment of dangerous substances emissions from construction products has been discussed by the CEN (European Committee of Normalization) normative ad hoc technical committee TC351, establishing harmonized leaching procedures for testing construction materials.
The main issues addressed within the RECYBÉTON project on this topic are “How different could be the leaching characteristics of concrete containing recycled aggregates 514(RAC) compared to concrete prepared with only natural aggregates (NAC)?” and “Do RAC comply with existing threshold values for the environmental assessment of construction materials?”
During the last two decades, several scientists, particularly within ISCOWA organization (International Society for the Environmental and Technical Implications of Construction with Alternative Materials), have studied the environmental assessment of construction materials containing waste in order to assess the environmental acceptability of using alternative materials in construction. Recycled aggregates (RA) are, with municipal waste incineration bottom ash and coal fly ash, one of the three main waste concerned by these scientific studies. In the framework of the RECYBÉTON project, the main leaching characteristics of RA and RAC described in the literature have been drawn up. Leaching tests have been conducted on concrete prepared according to the formulations of the RECYBÉTON project (see Appendix). The main goal was to compare the leaching characteristics of RAC with those of NAC.
France has not yet established any testing procedure or threshold values to assess the environmental acceptability of construction materials containing waste. Hence, the leaching characteristics of the RECYBÉTON materials have been determined by means of the Netherlands and German procedures for construction materials. The compliance with the local environmental acceptability conditions defined in these countries was verified.
