The rivalry between concrete and asphalt has become a classic contention, much like the climate in a Wisconsin bar during a Packers vs. Bears match-up or in the stands at a meeting of the Yankees and Red Sox. Historically, concrete has been seen as the underdog in this battle, going up against a material that's the perceived leader for parking lots and roads. But as asphalt prices rise and the concrete industry works on paving promotion, opportunities are opening up for owners to more clearly see the benefits of concrete.
A concrete parking lot offers owners several benefits over asphalt. For one, it has a lighter surface which reflects more light. This creates a brighter and safer parking lot and allows owners to save on energy bills with lower wattage lighting. The popularity of LEED-certified projects has opened doors for concrete because of its low albedo, or heat absorption, and help in lessening the heat island effect. Maintenance needs are also lower and concrete pavements are expected to last at least 20 years, resulting in a better life-cycle cost over asphalt.
In recent years, the industry has seen an increase in popularity of both full-depth concrete paving and whitetopping, a technique in which contractors pave a layer of concrete over an existing pavement such as asphalt. Whitetopping is less expensive than full-depth concrete paving and a much quicker and easier process for a contractor to perform. The National Ready Mixed Concrete Association (NRMCA) hopes concrete parking lots will have a 15 percent market share by 2010, up from 9 percent in 2005.
A recent mall parking lot whitetopping job by Docken Concrete of Verona, Wis., exemplifies the trend in the industry. The owner of the property already had one concrete parking lot and knew the advantages of concrete. "I get a better total product out of concrete," says Jim Grafft, president of Grafft Investments and owner of the Janesville Plaza. "Concrete doesn't have the maintenance issues [blacktopping does] and there's a better perceived value with concrete."
Grafft says he chose whitetopping for his parking lot because with the existing asphalt base he can take advantage of the strength of both the old pavement and the new one. The slightly higher cost for the whitetopping, $0.66 more per square foot than asphalt, presented an easy decision for Grafft. "When I compared one to the other, I felt I was getting very good value with the price of asphalt where it was. The extra money I spent on the concrete well offset the price of asphalt. It was a value thing," he explains.
Docken Concrete is a commercial and industrial flatwork company in south central Wisconsin. The company has been performing concrete paving since the early 1990s on projects such as heavy truck turnarounds and receiving areas at distribution plants and big box stores. It also performed full-depth concrete parking lot paving at some of these jobsites. The 100,000-square-foot whitetopping project at Janesville Plaza was the company's first foray into this increasingly popular type of concrete work.
Scott Docken, vice president of Docken Concrete, says the price increase of asphalt over the last year has put concrete and asphalt closer together in initial price, making it easier for owners to see the life cycle benefits of concrete over asphalt. "You're not comparing two equal things when you look at concrete and asphalt. You get a better end result with concrete," he says. Docken adds that concrete parking lots hold up better to heavy traffic. "Asphalt is an excellent base, and it's pre-existing so there is no waste," Docken says. "Trouble areas are easy to find and correct, and it eliminates compacting the subgrade."