University of California Pavement Research Center

This report presents the results of Phase I of a two-phase study to develop a new practice-ready design catalog for standard interlocking concrete pavements (ICP) based on a mechanistic-empirical (M-E) design approach. The new catalog is intended to replace the existing ASCE Standard 58-16 catalog, which was developed using the empirical AASHTO 1993 design method. Phase I objectives were to develop a framework for the M-E design process for ICP, assemble a database of appropriate values for critical design inputs, and develop an initial design catalog to be validated through accelerated pavement testing in Phase II.

Field investigations were conducted on selected ICP sites representing a range of structures, ages, traffic volumes, and axle-load distributions. Deflection testing was conducted to backcalculate as-built stiffness and variability of different layers in ICPs. Performance modeling was conducted using CalME, the M-E design program developed and maintained by the University of California Pavement Research Center (UCPRC) for the California Department of Transportation (Caltrans). The results confirmed that rutting is the main structural failure mechanism for ICPs.CalME predictions were consistent with observed rutting performance for low-volume local streets but generally underpredicted performance for sites with higher traffic, such as the Port of Oakland.

CalME was then used to develop a preliminary design catalog for ICP sections covering the full range of traffic and structures in the ASCE 58-16 empirical catalog. Worked examples were provided to illustrate catalog use and side-by-side comparisons with ASCE 58-16.

Finally, the report outlines a plan for the next phase to address remaining critical questions and calibrate CalME models for ICP through accelerated pavement testing.