Question

A rigid pavement is to be designed to provide a service life of 20 years and has an initial PSI of 4.4 and a TSI of 2.5. The modulus of subgrade reaction is determined to be 300 lb/in3. For design, the daily car, pickup truck, and light van traffic is 30,000; and the daily truck traffic consists of 300 passes of single-unit trucks with single and tandem axles, and 400 passes of tractor semi-trailer trucks with single, tandem, and triple axles. The weights for cars, pickups, light vans is two -2000 lb single axles, for single unit trucks are 10,000 lb steering, single axle and 22,000 lb drive, tandem axle and for tractor semi-trailer trucksare 12000 lb steering, single axle, 18,000-lb drive, tandem axle and 50,000 lb, trailer, triple axle.Reliability is 95%, the overall standard deviation is 0.45, the concrete modulus of elasticity is 4.5 million ln/in2, the concrete’s modulus of rupture is 900 lb/in2, the load transfer coefficient is 3.2, the drainage coefficient is 1.0. Determine the required slab thickness.

Answer 1