Asphalt Pavement Magazine - May/June 2013 - (Page 18)

Peter Judd, City of Vancouver General Manager of Engineering Services, explains how a wax (in the bag) made from household recyclables can help reduce the energy need to make asphalt pavements. Vancouver Adds WAX From Recycled Plastics to Warm Mix By James Careless I n Vancouver, British Columbia, city officials still rely on traditional asphalt mixtures for its roads. But change is coming: Since 2008, the city has been experimenting with warm-mix asphalt on both arterial and residential roads. Based on Vancouver’s experiences, moving to warm mix reduces the amount of natural gas required to make asphalt pavement at the city’s Kent Street asphalt plant by up to 20 percent. At the same time, switching from hot mix to warm mix cuts volatile organic compounds and carbon monoxide emissions by 30 percent and 20 percent respectively. Currently, Vancouver describes its warm-mix usage as being in the experimental stage, and the city use WMA for about 10 percent of its paving projects. Beyond these environmental benefits, the addition of recycled materials to Vancouver’s warm-mix pavements further improves the “green” profile of the city’s roadways. The city already designs its mixes with up to 20 percent reclaimed asphalt pavement (RAP) and has worked with recycled asphalt shingles (RAS), but it is eager to find new ways to make its pavements even greener. 18 • View past issues online at Looking to migrate from hot mix, Canada’s third-largest city decides to road-test innovative wax made from recycled plastic, at the same time as trying out warm-mix asphalt After much research, city staff opted to try a warmmix additive derived from post-consumer recycled plastics. The synthetic wax is made from ground-up high-density (#2) and low-density polyethylene (#4) plastics; the latter is derived from post-consumer plastic bottles and plastic shopping bags that do not have a higher use in the recycling chain. “We have been looking for a ‘poor man’s approach’ to adding recycled materials to our warm mix,” said Jeff Markovic, Superintendent of the City of Vancouver’s Kent Construction Materials Division. “We wanted a recycled materials wax that was easy to add at our Kent Street facility, didn’t affect the standard warm-mix application process, and stood up to the elements.”

Table of Contents for the Digital Edition of Asphalt Pavement Magazine - May/June 2013

Chairman’s Commentary
Industry News
Meet the Chairman
Vancouver Adds Wax From Recycled Plastics to Warm Mix
Building the Country’s Best
Smooth Landings at Austin Executive Airport
2012 Quality in Construction Awards
Industry Events
Index of Advertisers/

Asphalt Pavement Magazine - May/June 2013