Preserving Arlington Memorial Bridge

Liftech Hosts Asphalt Laydown, Compaction Seminar

Wed March 07, 2007 - Northeast Edition
CEG



More than 150 working professionals in the asphalt industry convened on Feb. 5 at Liftech Equipment’s Rochester, N.Y., facility for a fact-filled, one-day seminar about best practices in asphalt.

Instructor Jim Scherocman, a registered civil engineer and author of the Hot Mix Asphalt Paving Handbook and dozens of technical articles, is a noted expert.

“There definitely is a big need for this information, largely because of the turnover in the industry,” said Scherocman, who is booked a year in advance. “What we have done is retired knowledgeable people with the right background and replaced them with new people — but we haven’t trained them. Then the contractors have to meet the requirements of the owners, and the owners in some cases have no idea what to ask for.”

The Asphalt Laydown and Compaction Seminar was hosted by Liftech Equipment Companies, Sakai American Inc., and the IUOE, Local 832, a union devoted to construction workers and heavy equipment operators.

Scherocman told the group that basically the way a typical asphalt paver works has not changed since 1931 when the free-floating screed principle was instructed by the Barber-Greene Company.

But while the basic history has not changed, the need to achieve yield, thickness and smoothness at the same time has never been greater. Pressures caused by time constraints, budget, personnel, and weather never cease, while the average driver’s expectations for trouble-free driving are at an all-time high.

The ultimate performance of hot mix asphalt (HMA) concrete mixture under traffic is the standard by which all roads are judged. Scherocman said that, “the degree of compaction of an HMA concrete mixture is the single most important factor that affects the ultimate performance of the pavement. But while the HMA may have all the desired mix characteristics and properties when designed in the laboratory, the same mix may perform poorly if it is not compacted to the proper level of density on the roadway.”

The seminar highlighted and explained problems related to the advent of the Superpave mix design method used in the United States — including the lack of internal stability in the HMA material and the “tender zone” experience during the compaction process.

Calling it a “tender zone” hardly matches the potential for problems as Scherocman described how mixes move and shove excessively under the weight of the compaction equipment while being rolled.

Joe Verzino, president of Liftech, said that his company’s philosophy of selling “solutions,” not just equipment, led to his endorsement of this first-time educational seminar.

“We also have sponsored hands-on events, but today’s format is purely educational. The people here today came to listen to a person with lots of credibility. We plan to do many more of these seminars down the road.”

“It was a revelation,” said one Department of Transportation supervisor. “Seminars like this give us a chance to evaluate our own talent force, and to make sure we have the right person on the job.”