How is jointed plain concrete pavement (JPCP) thickness designed?

JPCP design (AASHTO 1993) considers fatigue of concrete from repeated loads and erosion of support. Thickness design involves: (1) Select reliability level and overall standard deviation, (2) Estimate traffic ESALs, (3) Characterize support - k-value (modulus of subgrade reaction) modified for base and seasonal variation, (4) Select concrete properties (Sc' - flexural strength), load transfer (dowels), and drainage, (5) Solve design equation relating slab thickness to inputs. MEPDG approach uses transverse cracking, faulting, and IRI as performance criteria with incremental damage analysis. Joint spacing, edge support, and load transfer efficiency are critical design elements.