1. Given the following design conditions, check if your thickness suggestion (see the individually assigned one below) is acceptable for fatigue and erosion performance according to the PCA design method. Attach PCA tables and graphs used for the design.

Design conditions

• Type: Four-lane highways with moderate traffic volume 
• Traffic: ADT = 4,200 (two-way) 

           Truck factor = 5%

           Growth rate = 4%

           Directional Distribution Factor = 0.5 (assumed) 

           Design Period = 30 years

            Axle load spectrum (see Table1)

• Subgrade: Clay, k = 150 psi/in
• Subbase: no subbase 
• PCC slab: Mr = 500 psi, Doweled JPCP, Concrete Shoulders

Concrete slab thickness that needs to be verified (use the assigned one only)

• Jack and Jeb (10 inch); 
• Jonathan and Wyatt (9.5 inch); 
• Carson and Faadhil (9 inch);
• Baley and Ryan (8.5 inch); and
• Dede and Taryn (8 inch)
• If your name is not listed here, use 10.5 inch

 

Table 1 Axle load spectrum

Single axle		Tandem Axle
Axle load (kips)	No of pass	Axle load (kips)	No of pass
12	732800	16	542400
14	234760	20	490800
16	168960	24	393959
18	122880	28	652800
20	94320	32	332000
22	42724	36	354399
24	25680	40	148800
26	12084	44	49684
28	4800	48	16848
30	2520	52	8493