A typical AASHTO design spreadsheet is structured into three distinct sections:
The probability that the pavement will perform its intended function (e.g., for interstate highways). Standard Normal Deviate ( cap Z sub cap R In Excel, use =NORM.S.INV(R/100) Overall Standard Deviation ( cap S sub o Typically ranges from for flexible pavements. Serviceability Loss ( cap delta cap P cap S cap I The difference between initial serviceability ( ) and terminal serviceability ( Resilient Modulus ( cap M sub cap R A measure of the subgrade soil stiffness, typically in psi. 3. Layer Thickness Calculation Once the required cap S cap N aashto flexible pavement design excel spreadsheet
Required SN = 4.5 (example).
The AASHTO flexible pavement design is based on an empirical relationship derived from the AASHO Road Test. The primary goal is to determine the required to support the projected traffic over the design life. The core equation involves several variables: A typical AASHTO design spreadsheet is structured into