Hot Mix Asphalt Technology - January/February 2008 - (Page 10)

PRESIDENT’S PERSPECTIVE f you watch some of the historical film footage on asphalt plants, you will note that the industry has made huge strides from the early plants that belched black smoke to our modern day facilities where emissions are very low and well controlled. For the period from 1960 to 1999, hot-mix asphalt (HMA) tonnage increased by 250 percent, but emissions decreased by 97 percent. Despite the progress that has been made, continuous improvement is a key factor for the success of the HMA industry. As global environmental awareness brings new challenges, we need to continue to take action and encourage innovations that make our facilities an even better neighbor, improve working conditions, and protect the environment. So are there any breakthroughs on the horizon, or do we see incremental change and improvement? There have been many positive developments over the years, but in my estimation, warm-mix asphalt technology has the potential for being one of the most important breakthroughs for the asphalt industry in over 50 years. It could rank with recycling, milling machines, the floating screed, SMA and Perpetual Pavements. I By Mike Acott Warm Mix: Keeping Several Steps Ahead Background Where did warm mix come from, where are we today, and what is the vision going forward? In the mid-1990s, NAPA, the National Institute for Occupational Safety and Health (NIOSH), the equipment manufacturers, the Federal Highway Administration (FHWA), and the labor unions put together a partnership to explore the idea of using engineering controls on paving machines. Each of the six U.S. manufacturers of highwayclass asphalt pavers devised ventilation systems to collect asphalt fumes from the screed area and vent them away from workers. These controls have now been in use for over a decade. In this time period we also 10 • Hot Mix Asphalt Technology – JANUARY/FEBRUARY 2008 saw that mix temperatures were edging upwards as a result of the implementation of Superpave, SMA, and the wider use of polymermodified asphalt. In 2000, a coalition of NAPA, Asphalt Institute, and the State Asphalt Pavement Associations published Best Management Practices To Minimize Emissions During HMA Construction, which provided guidance on how to reduce plant mixing temperatures. Also, NAPA and the State Asphalt Pavement Associations funded research at the National Center for Asphalt Technology (NCAT) on the effect of temperature, emissions, and odors. That research showed that temperature is one of the most significant drivers affecting the quantity and chemistry of fumes. Similar conclusions were reported by Eurobitume in 2007. By collecting and venting away emissions, the engineering controls could be considered a first generation “end of pipe technology.” However, it was clear that there were additional benefits if emissions could be controlled at the source. Based on the findings from the NCAT study, one option was to pursue technologies that could lower production and placement temperatures. In the late 90s NAPA made contact with Dr. Reinhold Ruhl who had formed a broad industry, labor, government coalition known as the German Bitumen Forum. This is very similar to the coalition NAPA had formed in the U.S. for the engineering controls project. The German Bitumen Forum had an active Temperature Reduction Working Group that was evaluating technologies that saved energy, reduced CO2 , and lowered emissions. In addition to the work in Germany, similar initiatives to reduce temperatures were occurring in France, Holland, Norway, South Africa, and elsewhere. Given the developments in Europe, a NAPA study team made up of producer/contractors conducted a warm-mix study tour of Germany,

Table of Contents Feed for the Digital Edition of Hot Mix Asphalt Technology - January/February 2008

Hot Mix Asphalt Technology - January/February 2008 Contents Chairman's Commentary President's Perspective A Conversation with the New NCAT Director NCAT Test Track: Real-Time Testing for Real-World Results Warm Mix: The Lights are Green Illinois Tollway Tests RAP in Fast Forwarded Research Big Creek Teams with TxDOT to Pave Using Innovative Asphalt Mix Diamond Achievement Commendation Issues a Call for Quality Calendar of Events CONEXPO-CON/AGG Product Review Index of Advertisers Advertisers.com

Hot Mix Asphalt Technology - January/February 2008

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