FWD Correlation Study Sameh Zaghloul, Ph'D', P'E' Zubair Ahmed, Ph'D' Khaled Helali, Ph'D' Presented

1
FWD Correlation StudySameh Zaghloul, Ph.D.,
P.E.Zubair Ahmed, Ph.D.Khaled Helali,
Ph.D.Presented at FWD Users Group Meeting,
2004
2
Objectives

• Assess the compatibility of different FWDs
• Correlate the deflection measurements made by
  using different FWDs

3
Correlation Study Test Site
FAA William J. Hughes Technical Center Atlantic
City, NJ
4
Study Features

• Participation of FWD/HWD units from various
  manufacturers
• Two cycles of testing (Cycles I and II)
• Testing of flexible and rigid pavement sections
• Different pavement structures in terms of layer
  types and thicknesses
• Three levels of subgrade strength (low, medium,
  high) in terms of California Bearing Ratio (CBR)
• Deflection testing conducted according to the
  Long Term Pavement Performance (LTPP) testing
  protocol
• Each unit given an alphanumeric identity (A, B,
  etc.)

5
FAA Material Designation
6
Pavement Layer Information for Cycle I Test
Sections
7
Pavement Layer Information for Cycle II Test
Sections
8
Comparison between Units A and B (Cycle I Testing)
9
Comparison between Units F and C (Cycle I Testing)
10
Comparison between Units A and B (Cycle I Testing)
11
Comparison between Units F and A (Cycle I Testing)

• Outliers
• far from confidence level

12
Comparison between Units F and B (Cycle I Testing)
13
Comparison between Units E and C (Cycle I Testing)
14
Summary of Cycle I Analysis Results
15
Comparison between Units I and G (Cycle 2 Testing)
16
Comparison between Units J and C (Cycle 2 Testing)
17
Comparison between Units J and E (Cycle 2 Testing)
18
Comparison between Units I and G (Cycle 2 Testing)
19
Comparison between Units J and K (Cycle 2 Testing)
20
Comparison between Units E and K (Cycle 2 Testing)
21
Summary of Cycle II Analysis Results
22
Thank You .