Improvement of oxygen transport functions in grave soils due to quicklime application depending on soil texture

The addition of CaO to the backfill improved the aeration properties in the grave simulations; this was indicated by a higher diffusivity and mostly higher O2 concentrations at all sites, which was related to a more continuous (C1) and less tortuous (Τ) pore system compared to the “Nil” treatment. However, under field conditions, the effectiveness of soil-lime-mixtures was reduced with increasing clay and soil moisture content. A permanently high water saturation in L2 at S2 and S3 offsets the positive effects of CaO on gas transport ability and therefore restricts an undisturbed gas exchange from the atmosphere to the coffin layer. Consequently, for grave soils with high stagnic/ground water level an additional drainage is needed, while for cohesive, clay-enriched soils a more pronounced homogenization and lime mixing intensity is recommended.