Mix Design and Specifications for Cement-Stabilized Bases
Friday, April 16 - 10 am CDT

Soil-cement is a highly compacted mixture of soil, cement, and water. Two types of soil-cement—cement-treated base (CTB) and full-depth reclamation (FDR)—are widely used as a pavement base for highways, streets, parking areas, airports, shoulders, and materials-handling and storage areas. Greater strength and durability combined with low initial cost are some of the advantages soil-cement has over other types of base material.

This one-hour webinar will discuss the applications, benefits, material requirements, mix design, and construction specifications of both CTB and FDR pavements. Register today.

Concrete Reconstruction of I-385 Provides Solid Savings for State

When construction of a 15-mile stretch of I-385 in Laurens County, South Carolina, is completed this fall, it will be a showcase for integrated concrete pavement technologies. The project includes a 50-year design, 10-inch concrete pavement overlay on existing asphalt. The outside shoulders will be placed with roller-compacted concrete. In addition, to bring the route up to modern interstate standards, South Carolina Department of Transportation (SCDOT) is paving the mainline 30 feet wide to include the inside shoulder with the same pull as the driving lanes.

The road closures started in January 2010 and the route is expected to be re-opened by August or September this year. By maintaining southbound traffic and rerouting northbound travel, the project time was reduced from the typical three years to eight months. Closing northbound lanes saved SCDOT more than $30 million and provided the opportunity to replace a bridge on the route while the road is closed.

The road, which had never been built to interstate standards, was costing the state of South Carolina up to $1 million a year in asphalt repair. More on integrated paving solutions.
Photo courtesy of Rob Thompson, SCDOT.

Quick Rehab of Loop Road Uses FDR

Cades Cove, located in a remote corner of Blount County, Tennessee provides 2 million visitors a year with fantastic scenery and an abundance of activities from wildlife viewing to hiking to a historical perspective of the area. This spectacular area, which is part of the Great Smoky Mountains National Park, recently completed rehabilitation of its famed 11-mile one way loop using full-depth reclamation (FDR) with cement.

Quick construction was of the utmost importance since only two months were permitted for complete shutdown of the road, minimizing the loss of visitors to only 10 percent. After considering three rehabilitation options, the choice was made that FDR with cement would repair the Cades Cove Loop Road. FDR rehabilitation was chosen for its cost, quick construction, and sustainable attributes. More on the Cades Cove Loop Road.

How soon can an RCC pavement be opened for traffic?

RCC has enough load carrying capacity to support occasional light vehicle traffic (such as a car entering or leaving a driveway) immediately following placement. This load carrying capacity is due to the compaction process, which creates friction between the confined particles (aggregate interlock) of the relatively dry mixture and allows for the occasional light vehicle to be placed on the RCC without damaging or disrupting the in-place material. However, heavier traffic is not recommended until the RCC has achieved adequate compressive strength—typically between 2,000 and 2,500 psi. More on opening RCC pavement to traffic.

RCC Showcased as Cost-Effective, Durable, and Sustainable Pavement Material

Ninety regional public and private transportation officials recently attended a roller-compacted concrete (RCC) demonstration and seminar in Martinsburg, W. Va. Following presentations on the design and construction of RCC by Tim McConnell of PCA and Bill Heape of Conewago Enterprises, Inc., the attendees were bused to the site of a new Essroc-Italicement Group cement plant where RCC is being placed for access roads, staging areas and driveways within the plant. The new plant is part of a multi-million dollar renovation including state-of-the-art vertical mills and computerized quality control features. More on the RCC project.

The cost of virgin aggregates is typically between 10 and 15 percent of the total construction cost of a new roadway section. A century of modern growth and urbanization in America has depleted once plentiful aggregate supplies. Frequently, aggregates come from either distant quarries at great expense or from local sources offering only marginal quality. Recycled concrete aggregates (RCA) have proven to be a sustainable substitute for virgin aggregates, in some cases proving to be an even better choice than the typically more costly virgin aggregate. According to a 2004 Federal Highway Administration study, 41 states recycle concrete for use as aggregates. More on RCA.

• National Association of County Engineers (NACE)
  2010 Annual Meeting and Management and Technical Conference
  April 25 - 29, 2010 in Fort Worth, Texas

• 2010 American Public Works Association (APWA) International Public Works Congress and Exposition
  August 15 - 18, 2009 in Boston, Mass.
  

Complete listing of conferences and training.

Mark Your Calendars for 2010