Proposed Loading Waveforms and Loading Time Equations for Mechanistic-Empirical Pavement Design and Analysis

Under the same applied traffic loading, time is traditionally assumed to be a function of only the vehicle speed and the depth beneath the pavement surface. Additionally, no definite loading waveform has been established and/or recommended for any one special loading situation. After numerous computations and analyses in this study, it was found that the loading time is not only a function of the vehicle speed and the depth beneath the pavement surface but is also a function of the moduli ratio between the layer of interest and the immediate succeeding layer below. Furthermore, the loading waveform changed with depth beneath the pavement surface and the moduli ratio. Based on the results of this study, new equations for more accurately determining the loading time were proposed. Additionally, the corresponding loading waveform, which is a function of the depth beneath the pavement surface and the moduli ratio, was recommended. Plausible results were also obtained when an iterated method was introduced to calculate the loading time using the equations proposed in this paper.

[1]  David H Timm,et al.  Perpetual pavement design for flexible pavements in the US , 2006 .

[2]  S F Brown,et al.  DETERMINATION OF YOUNG'S MODULUS FOR BITUMINOUS MATERIALS IN PAVEMENT DESIGN , 1973 .

[3]  Imad L. Al-Qadi,et al.  Frequency determination from vehicular loading time pulse to predict appropriate complex modulus in MEPDG , 2008 .

[4]  I. Al-Qadi,et al.  Measurement of Vertical Compressive Stress Pulse in Flexible Pavements: Representation for Dynamic Loading Tests , 2002 .

[5]  Imad L. Al-Qadi,et al.  Effects of tire configurations on pavement damage , 2005 .

[6]  Imad L. Al-Qadi,et al.  The Virginia smart road: The impact of pavement instrumentation on understanding pavement performance , 2004 .

[7]  Mohamed M El-Basyouny,et al.  Independent Review of the "Mechanistic-Empirical Pavement Design Guide" and Software , 2006 .

[8]  Leslie Ann Myers,et al.  Conversion of Testing Frequency to Loading Time: Impact on Performance Predictions Obtained from Mechanistic-Empirical Pavement Design Guide , 2006 .

[9]  R. D. Barksdale,et al.  COMPRESSIVE STRESS PULSE TIMES IN FLEXIBLE PAVEMENTS FOR USE IN DYNAMIC TESTING , 1971 .

[10]  Yang H. Huang,et al.  Pavement Analysis and Design , 1997 .

[11]  Tom Scullion,et al.  Perpetual Pavements in Texas: The Fort Worth SH 114 Project in Wise County , 2007 .

[12]  Gerardo W Flintsch,et al.  Conversion of Testing Frequency to Loading Time Applied to the Mechanistic-Empirical Pavement Design Guide , 2008 .

[13]  Imad L. Al-Qadi,et al.  Accuracy of Current Complex Modulus Selection Procedure from Vehicular Load Pulse , 2008 .