Technical information

viii
LIST OF FIGURES
Figure 2.1.1: Schematic layout of the 46 test sections at NCAT (Phase II) experiment .............. 2-2
Figure 2.1.2: Photograph of a typical NCAT truck (Priest and Timm, 2006) .............................. 2-3
Figure 2.2.1: Structural layers for sections N1 to N8 (Priest and Timm, 2006) ........................... 2-4
Figure 2.2.2: Final gradation of upper subgrade soil at N1 and N2 sections (Timm and
Priest, 2006) .................................................................................................................. 2-5
Figure 2.2.3: Gradation of base material at N1 and N2 sections (Timm and Priest,
2006) ............................................................................................................................. 2-6
Figure 2.2.4: Sub-layering of HMA in test sections N1 to N8 (Timm and Priest, 2006) ............. 2-7
Figure 2.2.5: Design gradation of different mix types used in the NCAT ‘structural
study’ (Timm and Priest, 2006) .................................................................................... 2-8
Figure 2.4.1: Photograph and dimensions (in inches) of an asphalt strain gauge (Timm
et al. 2004) .................................................................................................................. 2-21
Figure 2.4.2: Photograph of Geokon Earth Pressure cell Model 3500 ....................................... 2-22
Figure 2.4.3: Sensor layout for section N1 (based on Timm et al., 2004) .................................. 2-23
Figure 2.5.1: Vertical stresses (i.e. stress in Z) on top of the base course (upper chart)
and on top of the subgrade (lower chart) as a result of one truck pass.
Gauges positioned along the Y-axis in Figure 2.4.3 ................................................... 2-26
Figure 2.5.2: Horizontal strains in the loading direction (i.e., strain in Y) at the bottom
of the HMA course as a result of one truck pass. Gauges positioned along
the Y-axis in Figure 2.4.3 ........................................................................................... 2-27
Figure 2.5.3: Horizontal strains in the loading direction (i.e., strain in Y) at the bottom
of the HMA course as a result of one truck pass. Gauges offset by 24 in.
(610 mm) compared to the Y-axis in Figure 2.4.3 ...................................................... 2-28
Figure 2.5.4: Horizontal strains in the transverse direction (i.e., strain in X) at the
bottom of the HMA course as a result of one truck pass. Gauges positioned
along Y-axis in Figure 2.4.3 ....................................................................................... 2-29
Figure 2.5.5: Fatigued sections N1 (left photo) and N2 (right photo) ........................................ 2-30
Figure 2.5.6: Graphical progression of N1 and N2 rutting levels vs. number of applied
ESALs at the Track ..................................................................................................... 2-32
Figure 3.1.1: Schematic floor plan of INDOT APT facility ......................................................... 3-2
Figure 3.1.2: Picture of empty test pit and APT loading system .................................................. 3-3
Figure 3.2.1: Composition of APT test pavements n1 and n2 ...................................................... 3-5
Figure 3.3.1: Resilient modulus of unbound materials - a cross plot of calibrated
equation 3.3.2 values and test data ............................................................................. 3-10
Figure 3.3.2: Mix 1 dynamic modulus and phase angle master curves @ 15.5ºC ..................... 3-13
Figure 3.3.3: Mix 2 dynamic modulus and phase angle master curves @ 15.5ºC ..................... 3-14
Figure 3.3.4: Mix 3 dynamic modulus and phase angle master curves @ 15.5ºC ..................... 3-14