Question

(18%) A roadway design company is designing a rigid pavement for a four-lane northbound section of interstate. This pavement was designed with an 8-inch slab, 95% reliability, a 800 lb/in2 concrete modulus of rupture, a 5 million lb/in2 modulus of elasticity, a 3.0 load transfer coefficient, and an overall standard deviation of 0.25. The initial PSI is 4.6 and the TSI is 2.5. The pavement was conservatively designed (assuming the upper limit of the W18 design lane load) to last 20 years, and the module of subgrade reaction is 100 with a drainage coefficient of 1.0. What would be the 18-kip equivalent single-axle loads for the design lane road?

Answer 1

We know the equation for designing Rigig Pavements.

For rigid pavement we know the AASHTO equation for design is

reliability = 95%, so Z_R = -1.645, S₀ = 0.25, D = 8, delta (PSI) = 4.6 - 2.5 = 2.1

P_t = 2.5, S'_c' = 800, J = 3.0, C_d = 1.0, E_c = 5000000, k = 100

So based on this we calculate the W18 to be 5799580 ESALs

So design ESALS = 5799580

this is the number of ESALS that are acting on the road over the entire design period.

==============================================================================================

Please rate +vely to support and encourage us to keep giving quality solutions.