During the last 10 years, applications and production methods for roller-compacted concrete (RCC) — a stiff, zero-slump concrete mixture — have grown. Today, RCC has many applications, including industrial and commercial site paving, street construction, ports, military bases, interstate shoulders, highway bases, and more.
Roller-compacted concrete takes it name from the construction method used to build it. According to the Portland Cement Association (PCA), RCC is placed with conventional or high-density asphalt paving equipment, and then compacted with rollers.
RCC has the same basic ingredients as conventional concrete — cement, water and aggregates. But unlike conventional concrete it's a drier mix — stiff enough to be compacted by vibratory rollers. RCC pavements do not require joints, dowels, reinforcing steel, forms, or finishing.
RCC, originally used back in the 1970s to provide a solid base for heavy traffic at logging centers, is known for its strength and durability. It can withstand high concentrated loads and impacts from heavy industrial, military and mining applications.
Interest in RCC is growing. Approximately 150 people — contractors, developers, public works and transportation officials, and other professionals — attended the Sept. 25 RCC design and construction seminar in Louisville, Ky. Presented by the Southeast Cement Association, PCA, Great Lakes Cement Promotion Association, Kentucky Concrete Pavement Association, Kentucky Ready Mixed Concrete Association, Indiana Ready Mixed Concrete Association, and the Indiana Chapter — American Concrete Pavement Association (ACPA), the seminar provided detailed instruction on design and construction procedures for RCC, including appropriate applications, mix design and pavement design guidelines.
Robert Thompson, P.E., an engineer with Nicholas Savko & Sons Inc., Columbus, Ohio, was one of several speakers at the seminar. "RCC is by far one of the most exciting products our company has come upon," he says. He points out that RCC is a high-volume product requiring easy preparation and minimal labor.
Bryant Poole, P.E., District 7 engineer for the Georgia Department of Transportation, detailed Georgia's use of RCC to reconstruct shoulders on Interstate 285 on the west side of Atlanta. The existing asphalt shoulders were badly distressed and required reconstruction; so, the shoulders were milled out and replaced with RCC.
"We're very pleased with RCC," says Poole. "We think it is going to be very successful. It is going to be the wave of the future in limited applications."
Other speakers included Wayne Adaska, P.E., director of public works for Portland Cement Association, Skokie, Ill.; John Vaughan, technical service director, Irving Materials Inc., Louisville; Wouter Gulden, P.E., director of engineering and training, ACPA's Southeast Chapter, Dacula, Ga.; and Mike Kaelin, regional technology manager, Axim Concrete Technology.
In addition to the Louisville seminar, attendees traveled across the Ohio River to Speed, Ind., to view an ongoing RCC project at ESSROC Cement Corp.'s facility. A crew for Gohmann Asphalt & Construction, Clarksville, Ind., used Caterpillar paving equipment to place a section of RCC.