|FHWA > Engineering > Pavements > Concrete > High Performance Concrete Pavements: Project Summary > Chapter 39|
High Performance Concrete Pavements
|LANE NO.||PCC OVERLAY THICK (IN.)||HMA THICK (IN.)||HMA MIXTURE, BINDER1||JOINT SPACING (FT)||FIBERS IN CONCRETE MIXTURE||DESIGN 12-KIP LOAD APPLICATIONS2|
|5||2.5||5.5||SM, AC-10||4 x 4||Yes||210,000|
|6||2.5||5.5||SM, AC-20||4 x 4||No||140,000|
|7||2.5||5.5||SM, PM||3 x 3||Yes||420,000|
|8||2.5||5.5||SM, PM||3 x 3||No||350,000|
|9||3.5||4.5||SM, AC-5||6 x 6||Yes||350,000|
|10||3.5||4.5||BM, AC-20||6 x 6||No||245,000|
|11||3.5||4.5||BM, AC-5||4 x 4||Yes||455,000|
|12||3.5||4.5||BM, AC-20||4 x 4||No||350,000|
|1SM = surface mixture; BM = base mixture; PM = polymer modified asphalt.|
2Estimated design life was calculated using American Concrete Pavement Association design procedure based on as-built strengths, overlay design thicknesses, and 12-kip loads.
Figure 109. Layout of test sections and instrumentation for FHWA 1 project (FHWA 2004).
ALF = accelerated loading facility; LVDT = linear value displacement transducers; THK = thick
The test sections were instrumented with between 15 and 18 dynamic strain gauges. The gauges were installed near the top and bottom of the concrete overlay and on the surface of HMA. Deflections were measured in the interior of the slab and adjacent to the joint using linear variable displacement transducers.
Monitoring activities included collecting distress data and measuring faulting and roughness. Deflections and strains induced by the applied wheel loads were also recorded. Laboratory data collected included layer modulus values, flexural strengths, and bond strengths.
A summary of the performance of the test sections is provided in Table 59. Although a few of the sections exhibited significant cracking, many experienced very little cracking. The primary types of distress documented were corner, transverse, and longitudinal cracks with corner cracking being the most predominant distress. A small amount of faulting along some of the longitudinal and transverse joints was measured, but overall very little faulting developed. Test sections that contained an HMA with binders having a higher penetration tended to exhibit a slightly higher level of cracking. Reducing the panel size when overlaying an HMA with a soft binder tended to increase the performance of the overlay.
|LANE NO.||ACTUAL LOAD APPLICATIONS||NUMBER OF PANELS LOADED||NUMBER OF PANELS EXHIBITING CRACKING||RANGE OF LONGITUDINAL FAULTING (IN.)||RANGE OF TRANSVERSE FAULTING (IN.)|
|5||194,500 @ 12 kips||12||18||0.1-0.7||None|
|6||359,000 @ 12 kips||12||11||0.1-0.3||None|
|7||283,500 @ 12 kips||16||4||0-0.1||None|
|8||628,000 @ 12 kips||16||3||0.1-0.2||0-0.1|
|9||266,000 @ 12 kips||8||10||0.1-0.0.3||0-0.2|
|10||441,000 @ 12 kips||8||4||0.1-0.2||0-0.2|
|11||310,000 @ 10 kips|
762,630 @ 12 kips
|12||310,000 @ 10 kips|
762,630 @ 12 kips
Design recommendations based on the findings from this study are being prepared, and the database of information produced will be available to the public in conjunction with a report on the contents of the database.
The cracked slabs in Lane 6 and Lane 10 were repaired on April 28, 2000. Mostly panels with multiple cracks or loose or missing pieces of concrete were replaced. Five panels were replaced in Lane 6 and three panels in Lane 10. The steps followed in performing the repairs appear below.
The average depth of the repair area after the panels were removed for Lane 6 was 96.5 mm (3.8 in.) and 119.4 mm (4.7 in.) for Lane 10. This resulted in an increase in overlay thickness of 33 mm (1.3 in.) for the repairs in Lane 6 and 33 mm (1.3 in.) for the repairs in Lane 10. More information on the repairs can be found in the report prepared by CTL (2001).
The slump, air content, concrete temperature, and unit weight of the repair concrete were measured. The compressive strength, split tensile strength, modulus of rupture, and modulus of elasticity of the concrete were also measured. Information on the test results is available in the report prepared by CTL (2001).
Four panels were also removed from Lane 9 to investigate the removal of slabs using a small front-end loader. Additional loadings were not applied to Lane 9.
Additional 12-kip dual wheel loads were applied to each lane beginning 8 days after the repair and continuing until early August 2000. During this time, Lane 6 accumulated 400,000 load repetitions and Lane 10 427,000 repetitions. Two of the five panels repaired in Lane 6 exhibited cracking, and two of the three panels repaired in Lane 10 cracked. These cracks were primarily corner cracks.
Office of Infrastructure Research and Development
Turner-Fairbank Highway Research Center
6300 Georgetown Pike
McLean, VA 22101
Construction Technologies Laboratories, Inc. (CTL). 2001. UTW Pavement Repair Demonstration. Final Report. Innovative Research Foundation, Falls Church, VA.
Federal Highway Administration (FHWA). 2004. Ultra-Thin Whitetopping (UTW) Project.
|<< Previous||Contents||Next >>|
Office of Asset Management, Pavement, and Construction