144
Deflections were measured with geophones at the conventional posi
tions used by the FDOT. The measurements were made at radial distances
of 0, 7.87, 11.8, 19.7, 31.5, 47.2, and 63.0 in. from the center of the
FWD loading plate. It was not feasible to obtain deflection measure
ments at sensor 8 (radial distance of 72.0 in.), although D8 had been
used in developing some of the FWD layer moduli prediction equations.
Appendix B lists test results for each test pavement section.
5.3.4 Cone Penetration Tests
The cone penetration test consisted of penetrating the pavement at
a rate of 2 cm/sec with an electronic friction cone. The University of
Florida cone truck was used to conduct the tests. Three to four CPT
soundings were conducted, spaced in between the NDT test locations, as
illustrated in Figure 5.2. Each test was performed to a depth of
approximately 18 ft., unless bedrock or a hard layer was encountered.
Values of tip resistance, local friction, and friction ratio were
obtained.
The CPT data were generally collected from the surface of the
asphalt concrete layer through the pavement to the final depth of
exploration. Generally the 15 metric ton cone was used to conduct the
CPT tests, especially in testing through the asphalt concrete and base
course layers. The data acquisition system was used to obtain plots of
the CPT test results. Appendix C shows profiles of tip resistance,
local friction, and friction ratio for the tests conducted on each test
pavement. The hole created by the CPT was used to determine the loca
tion of the water table. This was performed by inserting a moisture
meter into the hole. Table 5.1 lists the depth of water table for each
test site.