An axle weight study on a section of highway gave t highway. Assume SN = 4 and p₁ = 2.5. truck factor - Axle Load Group: Single (1,000 lb) 4 6 10 14 18 20 22 24 26 No. of Axles p 1,000 Vehicle 695 783 498 151 62 39 7 4 3

Repeat Problem 19-7 using two different depths of untreated aggregate bases of 6 in. and 12 in. Highway contractors in your area can furnish rates for providing and properly laying an asphalt concrete surface and untreated granular base. Assume a structural coefficient of 0.12 for the base course. If these rates are available, determine the cost for constructing the different pavement designs if the highway section is 5 miles long and the lane width is 12 ft. Which design will you select for construction?

An existing rural 4-lane highway is to be replaced by a 6-lane divided expressway (3 lanes in each direction). Traffic volume data on the highway indicate that the AADT (both directions) during the first year of operation is 24,000 with the following vehicle mix and axle loads. Passengercars=50percent 2-axle single-unit trucks (12,000lb/axle)=40percent 3-axle single-unit trucks (16,000lb/axle)=10percent The vehicle mix is expected to remain the same throughout the design life of 20 years, although traffic is expected to grow at a rate of 3.5 percent annually. Using the AASHTO design procedure, determine the minimum depth of concrete pavement required for the design period of 20 years. Pi=4.5J=3.2Pt=2.5Cd=1.0Sc=650lb/in.2So=0.3Ec=5106lb/in.2R=95k=130lb/in.3

Repeat Problem 20-12, with the slab containing temperature steel in the form of welded wire mesh consisting of 0.125 in.2 steel/ft width. The modulus of steel, Es, is 30106lb/in.2 , Ec=5106lb/in.2 , and h=6inches .