Evaluation of the AASHTO Design Equations and Recommended ImprovementsStrategic Highway Research Program, National Research Council, 1994 - Technology & Engineering - 214 pages One of the primary objectives of the Strategic Highway Research Program Long Term Pavement Performance (SHRP-LTPP) studies is to improve the ability of highway engineers to design new and overlaid pavement structures. The specific analyses discussed in this report were aimed at evaluation of the American Association of State Highway and Transportation Officials (AASHTO) pavement design equations (for both new and overlaid pavements). Initial analyses confirm that although improvements have been made to the AASHTO design equations over the years, the equations still do not fully explain data from North American pavements. Recommendations for the improvement of the design equations are provided; however, the highway community at large supports replacing the limited equations with a comprehensive design system that considers all distress types. |
Common terms and phrases
AASHO Road Test AASHTO equation AASHTO model AASHTO overlay design AASHTO procedure AASHTO rigid pavement AC overlay APSI Asphalt b₁ backcalculated Base Thickness CESAL CRCP Cumulative KESALS Data Set Design Matrix design period developed distress Doweled Joint Drainage Coefficient Elastic Modulus ESALS estimated Evaluation of AASHTO Granular Base HMAC Thickness Inches inference space joint spalling JPCP JRCP Layer Thickness longitudinal cracking LTPP Data Base original AASHTO overlay design procedures overlay of PCC Overlay PSR overlay structural capacities overlay thickness pavement design equation pavement sections pavement structure PCC pavement percent reliability Predicted KESAL predictive equation PSI LOSS Ratio of Predicted reliability level resilient modulus rigid pavement design RMSE roughness Rut Depth Sand AC Yes sensitivity analysis serviceability loss soil cement structural number subgrade moduli terminal serviceability test sections transverse cracks unbonded PCC overlay values Viscosity W-F Sand AC x₁