Determination of coefficient of thermal expansion effects on Louisiana's PCC pavement design.

794451727Final report; Feb. 1, 2007-Apr. 31, 2009.PDFTech ReportFHWA/LA.11/45107-2C / 736-99-1450ExpansionThermal expansionExpansion jointsPavement designThermal expansionPortland cementCement additivesTestingPortland cement concreteAdditivesMechanical properties of pavements expressed numericallyLouisianaLouisiana Transportation Research CenterShin, Hak-ChulChung, YoonseokLouisiana State University (Baton Rouge, La.). Dept. of Civil and Environmental EngineeringLouisiana. Dept. of Transportation and DevelopmentLouisiana Transportation Research CenterUnited States. Federal Highway AdministrationNTL-HIGHWAY/ROAD TRANSPORTATION-Pavement Management and PerformanceNTL-HIGHWAY/ROAD TRANSPORTATION-DesignUS Transportation CollectionWith the development of the Mechanistic Empirical Pavement Design Guide (MEPDG) as a new pavement design tool, thecoefficient of thermal expansion (CTE) is now considered a more important design parameter in estimating pavementperformance including cracking, faulting, and international roughness index (IRI). This study was conducted to measuretypical CTE values of Portland cement concrete (PCC) pavements having various aggregates used in Louisiana and toinvestigate the relationship between CTE and other critical variables such as aggregate types, age of concrete, dimension ofspecimen, amount of course aggregate in mixture, relative humidity, and concrete mechanical properties. AASHTO TP 60-00was used for measuring concrete CTE and a recently new standard test method, AASHTO T 336-09, was adopted to replacethe TP 60-00. A calibration factor was developed to convert the CTE values measured by AASHTO TP 60-00 to that of thenew standard testing method. From the analysis of measured data, it was found that aggregate types, coarse aggregateproportion, and relative humidity have a significant influence on CTE. This finding was confirmed with a statistical analysis ofvariance (ANOVA). CTE tests and mechanical property tests were also performed at different ages to provide input data forLevel 1 design of MEPDG. Based on the results of the MEPDG analysis, current maximum joint spacing [20 ft. (6.1 m)] injointed plain concrete pavement (JPCP) can be adjusted to 15 or 18 ft. (4.6 or 5.5 m) when Kentucky limestone is used as acoarse aggregate