thermal roughening
n.β Β«In February, crews started blasting the sidewalks with a blowtorchβor “thermal roughening,” as they call itβto burn away the slippery top layer of stone.Β» ββMayor Bloomberg orders $1M worth of repairs on sidewalk near City Hall” by Adam Lisberg New York Daily News (New York City) Apr. 14, 2008. (source: Double-Tongued Dictionary)