Terminal 115, located just south of Seattle, Wash., is occupied by Northland Services, Incorporated—the Port of Seattle’s fourth largest tenant. On average, 57,000 tons of cargo is pushed through the Terminal each month. When rehabilitation became necessary for this busy yard, special consideration was given to the alternatives assessed before deciding on a paving and pavement foundation method. Because of Seattle’s heavy precipitation, it is important that marine terminals carrying heavy loads be properly drained and resist pavement deflection. A properly designed FDR pavement was selected for this project as it could distribute large wheel loads to weak subgrade soils, maintaining a stable platform for many years.

Full-depth reclamation (FDR) is a process in which the existing asphalt surface is pulverized in place and blended with the underlying base, subbase, and/or subgrade materials, mixed with portland cement, and compacted to provide a new stabilized base. A new surface course is then applied, which completes the FDR process, providing a new pavement structure using recycled materials from the failed pavement. For Terminal 115, FDR was found to be the most cost efficient solution—especially when working through Seattle’s naturally wet environment.

At press time, five additional acres are being added to the project due to cost savings. Read the complete story by Katherine M. Dingman, Harbor Consulting Engineers, Inc.

Performance of Soil-Cement and Cement-Modified Soil for Pavements: Research Synopsis

This 4-page information sheet highlights findings from a comprehensive research project to identify new approaches to improving the performance of soil-cement bases and cement-modified soils in pavements. One significant reported finding was the introduction of a new test method called the Tube Suction Test (TST) for assessing the moisture susceptibility of soil-cement materials. The TST is shown to correlate well with the existing soil-cement wet-dry and freeze-thaw durability tests. Download the pdf or purchase. The complete research report is available as RD120.

Cement Association of Canada Studies Permeability of RCC

Interest in using roller-compacted concrete (RCC) for compost platforms in North America and Europe is growing because of its low construction cost and very tough surface durability. Recently the Cement Association of Canada (CAC) contracted with a laboratory in Quebec, Service d’Expertise en Materiaux (SEM) Inc., to compare the permeability of RCC with conventional concrete.

The permeability was measured through the use of special laboratory equipment developed by SEM. Permeability testing was performed at an average water pressure of 110 psi for a period of 40 days. Although the variability of permeability measurements is high, the results indicated that both the conventional and the roller-compacted concrete were in the range of 1 x 10 ^-11 cm/sec. This low permeability is considered satisfactory for the applications being investigated. Read the full report.

How soon can a newly constructed cement-stabilized roadway base—whether a cement-treated base (CTB) or a full-depth reclamation (FDR) base—be opened to traffic?

A properly constructed cement-stabilized roadway base is one in which the roadway materials are homogenously blended with the designed amount of portland cement and water, and then compacted, graded, finished, and cured through the application of a bituminous compound, a sealing membrane, or kept continuously moist for a period of seven days.

Completed portions of these cement-stabilized bases can be opened immediately to low-speed local traffic and to construction equipment, provided the curing material or moist curing operations are not impaired. The section can be opened up to all traffic after the cement-stabilized base has received the curing compound or subsequent bituminous or concrete surfacing. If continuous moist curing is employed in lieu of a curing compound or subsequent surfacing within seven days, the cement-stabilized base can be opened to all traffic after the 7-day moist curing period. Each of these traffic placement alternatives is dependant upon the hardened cement-stabilized base being sufficiently stable to withstand marring or permanent deformation.

More soil-cement FAQs.

Get Your Questions Answered at the PCA Booth at:

• National Association of County Engineers (NACE) 2006 Annual Meeting and Management & Technical Conference
  April 9-13, 2006 in Grand Rapids, Michigan

• 2006 LTAP/TTAP National Conference
  July 30-August 3, 2006 in St. Petersburg, Florida

• Western Association of State Highway and Transportation Officials (WASHTO) 2006 Annual Meeting
  August 26-30, 2006 in Honolulu, Hawaii

• 2006 APWA International Public Works Congress and Exposition
  September 10-13, 2006 in Kansas City, Missouri
  
  

The Road Recycled: Full-Depth Reclamation With Cement

This pocket-sized CD includes a 5-minute video on the full-depth reclamation (FDR) process, including several testimonials from county transportation officials highlighting its benefits. Also featured on the CD is a brief overview of soil-cement, case studies, introductory publications on soil-cement and FDR, and a suggested specification on FDR. CD032—$3

Rolling Out RCC on I-285

We've packaged reprints of an article from the Dixie Contractor (RP132) and an 8 1/2-minute video from the Georgia DOT (CD065) describing the use of roller-compacted pavement (RCC) in rebuilding 34 miles of shoulders on the Atlanta I-285 Perimeter Highway.

With this special offer you will get 10 copies of each for only $15. (A $33 value.)
XC050—$15 Offer expires April 30, 2006.