Field Evaluation of Built-in Curling Levels of Rigid Pavements

Sponsor: Minnesota Department of Transportation

PI: Jacob Hiller

This project assesses the mechanisms and methods to assess built-in curling of jointed plain concrete pavements. Through the use of literature review or previous work, material, geometric, restraint, curing and local ambient relative humidity were found to be factors affecting both construction curl and drying shrinkage, leading to built-in curl of concrete slabs. Through the extensive use of a finite element program, an artificial neural network (ANN) was developed to backcalculate the built-in curl of an in-service concrete slab using falling-weight deflectometer testing for a variety of parameters. This ANN was used to evaluate existing concrete test cells at the MnROAD facility. In addition to non-destructive evaluations, significant studies into surface profiling of these same test cells was conducted to evaluate the most accurate and simplified method for evaluating built-in curl. While the nondestructive ANN method evaluates the interaction of the concrete slab with the underlying layers, the surface profiling method does not directly reflect this interaction, but instead gives an understand of the slab’s curvature at the surface. Comparisons between these methods as well as between numerous different surface profiling methods were conducted.

Jacob Hiller
Jacob Hiller

Improvement of Michigan Climatic Files in Pavement ME Design

SPONSOR:  MICHIGAN DEPARTMENT OF TRANSPORTATION

PI:  Zhanping You

The objectives of this study are the following: (1) check the quantity and quality of existing data for weather stations in Pavement Mechanistic-Empirical (ME) Design; (2) investigate the sensitivity of required pavement designs to climatic inputs; (3) determine sources of additional weather data that can be utilized in Pavement ME Design; (4) determine where additional weather stations would be beneficial; (5) run quality checks on additional weather data and weather stations and place into the correct format for Pavement ME Design; and (6) develop a procedure to choose weather data for virtual stations for gap areas where there is no actual weather station.

Zhanping You
Zhanping You
Jianping Dong
David Watkins
David Watkins
Jacob Hiller
Jacob Hiller