CE $410$ Transportation Engineering and Design

Instructions:

Use AASHTO Pavement Design Guide.

Show all steps.

You must write with pen on the white blank pages supplied to you and staple all the pages together with this page as the cover page. Your submission will not be accepted or graded if you do not follow the instructions.

Problem $1.$ Calculate the design ESAL for the following traffic data. Use AASHTO method of calculation of ESAL for pavement design.

Two$-$way AADT $=20,000.$ Percent of trucks $=10\%$ of AADT. Directional distribution factor $=0\mathrm{.}50.$ Lane distribution factor $=0\mathrm{.}90.$ Design life time of the pavement $=20$ years. Traffic growth $=4\mathrm{.}0\%$ per year. $SN=5\mathrm{.}0.$

$\backslash$table$[[$Truck Type,Percent,Axle Type,No$.$ of Axles,Axle Weight $($kips$)],[$I$,40,$SA$,1,16],[,,$DA$,2,40],[$II$,60,$SA$,1,20],[,,$DA$,2,36]]$

Problem $2.$ Two alternative pavement structures are to be designed with the following data. Find the thickness of each layer for the two alternative designs. All layers have good drainage with $5\%$ of time exposed to near saturation condition. The structural numbers are provided $($no need to use the design chart$).$

$\backslash$table$[[$Alternative$,$Layers,Modulus $($ksi$),$SN$],[$A$,$HMA,$250,2\mathrm{.}5($HMA$)],[,$Base,$20,3\mathrm{.}5($HMA $+$ Base$)],[,$Subbase,$15,5\mathrm{.}2($HMA $+$ Base $+$ Subbase$)],[$B$,$HMA,$250,2\mathrm{.}5($HMA$)],[,$Base,$25,5\mathrm{.}2($HMA $+$ Base$)]]$