CHARACTERISATION OF MSWI BOTTOM ASH FOR POTENTIAL USE AS SUBBASE IN GREENLANDIC ROAD CONSTRUCTION

The waste management situation in Greenland needs to be improved. Most waste in towns is incinerated with only limited separation prior to incineration and the bottom ash residue is disposed of at uncontrolled disposal sites. The bottom ash could be a valuable resource within the expansion of infrastructure due to increased oil and mineral exploitation. Thus, in this study MSWI bottom ash from a Greenlandic incinerator was tested for possible reuse as subbase in road construction. The mechanical properties (grain size distribution, wear resistance and bearing capacity) showed that the bottom ash was acceptable for reuse after some small adjustments in the grain size distribution to prevent frost sensitivity. Results obtained from heavy metal content and heavy metal leaching complied with the Danish guideline values for reuse of waste materials in construction. Leaching of Cu and Cr was high from small grain sizes and could be reduced by removing some of these smaller grain sizes to obtain the stability requirement of the bottom ash. All in all, this study showed that the Greenlandic bottom ash has potential for being reused in road construction.