The effect of compaction on the leaching and pollutant emission time of recycled aggregates from construction and demolition waste

A percolation test for materials under compaction conditions was designed. The release levels measured in the water percolated through the compacted aggregates were compared with a conventional percolation leaching test. Besides, the compliance test allowed identifying the most conflictive elements according to the measured concentrations in the leachate: chromium and sulphate. The results revealed that under compaction, the highest levels of release were obtained for the concrete material. It was due to its high susceptibility to compaction which increased the content of fine particles affecting to the leaching behaviour. The study also includes the formulation of an equation to determine the emission release time of pollutants. Calculations were developed for two common applications as granular material: embankments and structural road layers.