Flexible pavement design in Wichita demands more than a standard catalog section. The city’s underlying geology—predominantly the Wellington Formation with its expansive shale and clay layers—creates subgrade conditions that punish under-designed asphalt structures. We see it in the premature alligator cracking along Kellogg Avenue and the rutting that appears five years early on collector roads south of the Arkansas River. Our approach integrates the AASHTO 1993 design guide with Mechanistic-Empirical Pavement Design Guide (MEPDG) calibration specific to Kansas DOT historical performance data. Before any layer thickness calculation, we run a full geotechnical investigation: in-situ permeability testing quantifies drainage characteristics of the local silty clays, while grain-size analysis and Atterberg limits establish the soil classification per ASTM D2487. Wichita’s climate zone—hot summers with surface temperatures exceeding 130°F and winter freeze-thaw cycling—requires careful binder grade selection; we specify PG 64-22 or PG 70-22 depending on traffic loading and layer position, always referencing KDOT Standard Specifications for material acceptance.
A 1-inch increase in asphalt thickness on untreated expansive clay subgrade in Wichita adds 8–12 years to pavement life—the most cost-effective investment you can make before the first lift is paved.
