Pavement thickness, this section provides comparison tables showing the various rigid and flexible pavement thicknesses calculated according to the aashto pavement design methodology. Palmer used figure 3.1 “design chart for flexible pavements based on using mean values for each input” from aashto 1993 and solved the equation for the required structural number. Cbr method recommended by california state of highways 2.
Flexible pavement designs based on aashto 1993 guide
Cae 419 introduction to transportation engineering and design lecture 5 highway pavement
So, we must check if the final sn 3 is similar to the assumed sn. Viii notations and abrivation aasho is american association of state highway officials is layer coefficients representative of surface courses. S estimated total 18 kip esal applications, wix (millions) = design chart for flexible pavements based on using mean values for each input effective roadbed soil resilient modulus, m. Pavement is to be designed with jointed reinforced concrete with dowels and untied asphalt shoulders.
Cbr method recommended by irc
(lb/in.)x100 at design structural number, sn design serviceability loss, apsi.006 roadbed soil modulus, month relative damage u ma (psi).01 20 jan. Higher sn means stronger pavement, thus the impact of traffic on pavement deteriorations is less. Flexible pavement design by cbr method is used to determine the total thickness of pavement. S0=0.35 − with traffic variation:
The esal and pavement thickness values shown in the tables are dependent upon the design parameters used in the calculations.
Generally there are two methods to design the pavement from cbr (california bearing ratio) value. In the aashto flexible pavement design, traffic is considered in terms of esal for the terminal psi (table 20.13 for p t = 2.5.) we must assume the structural number of the pavement. The effective modulus of subgrade reaction (corrected for loss of support) k= 180 pci. Austroads pavement design guide 2003 two design processes for flexible pavements empirical design chart • flexible pavements consisting of unbound granular materials, sprayed seal surface mechanistic • flexible that contain one or more bound layers
The analytical study comprises federal aviation administration method (1996) and barenberg's design method (1975) to interpret the design charts.
The input parameters used, evaluation criteria, and the results are summarized below, in table 1.
