Unformatted text preview: 2 , load transfer coefficient of 3.0 and drainage coefficient of 1.0). (Answer: 17.14 years) 4.X2. A rigid pavement on a new interstate (3 lanes each direction) has been conservatively designed with a 12-inch slab, an E c of 5.5 × 10 6 lb/in 2 , a concrete modulus of rupture of 700 lb/in 2 , a load transfer coefficient of 3.0, an initial present serviceability index of 4.5, and a terminal serviceability index of 2.5. The overall standard deviation is 0.35, the subgrade CBR is 25, and the drainage coefficient is 0.9. The pavement was designed for six hundred 30-kip tandem axles per day and fourteen hundred 20-kip single axle loads per day. If the desired reliability was 90%, how long was this pavement designed to last? (Answer: 46 years)...
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- Spring '09
- Transportation Engineering, Road, Truck, overall standard deviation