Evaluation of non-destructive technologies for construction quality control of HMA and PCC pavements in Louisiana.

PDFTech ReportFHWA/LA.12/493Nondestructive testsHot mix paving mixturesPortland cement concretePavement performanceQuality assuranceQuality controlDeflectometersPortable equipmentLouisianaLouisiana. Dept. of Transportation and DevelopmentIcenogle, PatrickKabir, SharearLouisiana Transportation Research CenterUnited States. Federal Highway AdministrationUS Transportation CollectionCurrent roadway quality control and quality acceptance (QC/QA) procedures for the Louisiana Department of Transportation andDevelopment (LADOTD) include coring for thickness, density, and air voids in hot mix asphalt (HMA) pavements and thickness andcompressive strength for Portland cement concrete (PCC) pavements. Non-destructive testing (NDT) devices, such as the light weightdeflectometer (LWD) and the portable seismic pavement analyzer (PSPA), provide a non-destructive and portable means of quick inplacedetermination of pavement properties, resulting in an increase in sampling frequency to supplement coring. Many researchers haveshown good trends between measurements of the NDTs and other pavement properties, though variability has shown to differ from reportto report. The PSPA exhibited seismic modulus values of the surface layer with an average coefficient of variation (CoV) of 2 to 15percent for repeat collections without moving the apparatus. The PSPA variability increased to a range of 6 to 28 percent if the apparatuschanged orientation or moved within a close proximity. The LWD exhibited deflections values of the pavement structure with an averageCoV of 4 to 12 percent for repeat collections without moving the apparatus. The PSPA exhibited project wide seismic modulus valueswith a CoV between 1 and 32 percent. The LWD exhibited project wide deflection values with a CoV between 18 and 55 percent.Factors that increased variability include: deterioration of the feet pads, presence of vibrations, placement of a foot into a groove, testingclose to joints, and temperature. Changing the orientation of the sensors showed to increase the variability of the PSPA measurements;however, the variability increase is no different than moving the apparatus within a close proximity. Orientation of the sensors did notshow to have a bias to measuring parallel or perpendicular to the paving direction. The strength gain measured by the PSPA correlatedwell with the strength gain of laboratory testing for only one of the PCC data sets for this study. The LWD deflections correlated wellwith the FWD deflections, but the back-calculated moduli of the surface layer did not correlate well. No trends were observed betweenthe PSPA and LWD. A preliminary sampling procedure was developed for the PSPA as a quality control tool in Louisiana