The eruption of Mount Pinatubo in the Philippines in 1991 resulted in large volcanic deposits known as lahar. This material has the potential for being a source of aggregate used in road construction.
This document reports on investigations into the use of lahar as a fine aggregate in bituminous mixtures.
O’Connell, M.J.; Ford, W.G.; Faustino, R.; Valencia, N. Performance of volcanic ash in bituminous mixes. (2004)