Type of Pavement
Layer
Flexible Rigid (CRCP) Composite w/ CTB Composite w/ CRCP Base
HMA 288
(11.5)
- 225
(9)
175
(7)
CRCP
-
350
(14)
- -
CTA
a
-
150
(6)
200
(8)
-
Granular base
200
(8)
- -
-
CRCP base
-
-
-
200
(8)
Subbase 225
(9)
- 225
(9)
225
(9)
a
Note: CTA = cement-treated aggregate
Table 11 shows the work schedule used in the LCCA for this study. The VDOT (2002)
guidelines for the flexible, rigid (CRCP), and semi-rigid (composite with CTB) pavement
structures were used. A continuous 10-year functional mill and overlay maintenance activity
was assumed for the composite with CRCP base pavement based on the literature (NCHRP,
2004; MDSHA, 2002; Smith et al., 2001).
A 50-year analysis period was used as recommended by VDOT. The unit prices of
various items were obtained from the average state bid tabulations published on VDOT’s website
(VDOT, 2007). The unit weight values for AC, aggregates, and drainage layer remained
unchanged for the volumetric computations. All costs computed were based on a 1-mile road
section. The present worth (PW) method was selected to compare all the different pavement
alternatives. A discount rate of 4%, as recommended by VDOT and the FHWA, was used.
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