Master of Science in Civil Engineering (MSCE)
Civil and Environmental Engineering
The objectives of this study were to investigate the variability in the physical and mechanistic properties of HMA due to production, characterize and compare the mechanistic properties of roadway cores and laboratory compacted samples, develop the relationship between modulus from in situ NDT and those obtained from laboratory tests on roadway cores, and compare air voids measurements between laboratory and field test methods. Six ongoing rehabilitation projects in Louisiana were selected, in each of which several test sections were tested. Comparative analyses were conducted on density measurements between two laboratory (AASHTO T-166 and ASTM D6752-02, or Vacuum sealing) and one in situ test (Pavement Quality Indicator) methods. Three types of nondestructive in situ test (NDT) devices, Falling Weight Deflectometer (FWD), Light Falling Weight Deflectometer (LFWD), and Potable Seismic Pavement Analyzer (PSPA) were conducted on asphalt layers. Four laboratory mechanistic tests including Indirect Tensile Strength test (ITS), Indirect Tensile Resilient Modulus test (ITMr), Frequency Sweep at Constant Height test (FSCH), and Loaded Wheel Tracking (LWT) test were conducted on roadway cores and/or Superpave Gyratory Compactor (SGC) samples. High variation was observed in mixture composition and air voids, as well as mechanistic properties along the mixture production. A strong correlation was observed between the two laboratory air void measurement methods. In general, SGC samples had higher mechanistic properties than those of roadway cores. Good correlations were observed between roadway cores and SGC samples in terms of complex shear moduli and indirect tensile resilient moduli. A methodology was developed for the prediction of laboratory resilient modulus from the in situ PSPA test parameter. Field test results indicated that the LFWD test might be used as an alternative for the FWD test in pavement structure evaluation. Pavement Quality Indicator (PQI) results did not correlate well with laboratory air void measurement methods.
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Zhang, Chenggang, "Comparative study of the physical and mechanistic properties of HMA mixture: field vs laboratory" (2005). LSU Master's Theses. 2244.
Louay N. Mohammad