|FHWA > Engineering > Pavements > Concrete > High Performance Concrete Pavements: Project Summary > Chapter 34|
High Performance Concrete Pavements
|Cement (lbs/yd3)||ASTM C150 Type III||705|
|Aggregate (lbs/yd3)||1.5 in.||940|
|0.375-in. Pea Gravel||140|
|Air-entraining admixture (oz/yd3)||ASTM C260||11|
|Water-reducing admixture (oz/yd3)||ASTM C494||30.3|
|Set-retarding admixture (oz/yd3)||ASTM C494 / Delvo||17.6|
|Air content||6.3 percent|
|Unit weight||149.8 lb/ft3|
|Concrete temperature||85 °F|
|Air temperature||82 °F|
Figure 93. Strength-time relationship developed for WA 1 project.
The contractor prepared and executed an hourly progress schedule during the intersection closure. Figure 94 shows the contractor's critical path method schedule (Nemati et al. 2003). The approach legs were rebuilt in the days prior to the complete intersection closure. A rotomill was used to remove the existing pavement and base at the intersection to a depth of 304.8 mm (12 in.), which was accomplished in a single pass. Concrete was placed in alternate sections, and then the sides of the newly placed pavements acted as forms for the interim sections. In this way, a significant amount of time was saved by not erecting and removing side forms for the interim sections.
Figure 94. Contractor's critical path method schedule for WA 1 project.
In this project, liquid curing compounds meeting ASTM C309 requirements were applied to the surface and exposed edges of the concrete pavement at a rate of one gallon per 13.9 m2 (150 ft2). The sawcutting at the intersection typically began within 6 hours of concrete placement. After sawing, the joints were sealed with a hot-poured asphaltic material.
Maturity meters were used in this project to monitor the strength gain in the concrete and determine the appropriate time for stripping forms and opening the pavement to traffic. The intersection was opened to traffic on Sunday between 4:00 p.m. and 6:00 p.m., well ahead of the originally scheduled 6:00 a.m. Monday morning opening.
The reconstruction of the intersection at SR 395 and Kennewick Avenue using accelerated construction techniques and complete weekend closure was completed successfully. The intersection was opened to traffic 16 hours ahead of the scheduled opening time. The breakdown of the time actually spent on each activity during the reconstruction is shown in Figure 95 (Nemati et al. 2003). As a result of the traffic control and public relation management, complaints from the public were reduced by over 70 percent compared to a project constructed 2 years before (Nemati et al. 2003). The unit price for reconstruction of the intersection at SR 395 and Kennewick Avenue is 168.26/m 2 ($15.58/ft 2) (Nemati et al, 2003).
Figure 95. Breakdown of time consumed by each construction activity on WA 1 project.
Kamran M. Nemati
University of Washington
P.O. Box 95233
Seattle, Washington 98145-2233
Jeff S. Uhlmeyer
Linda M. Pierce
Washington State Department of Transportation
P.O. Box 47365
Olympia, WA 98504-7365
Nemati, K. M., J. S. Uhlmeyer, L. M. Pierce, and J. R. Powell. 2003. Accelerated Construction of Urban Intersections with Portland Cement Concrete Pavement (PCCP). Final Report. Federal Highway Administration, Washington, DC.
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