A LABORATORY STUDY OF THE DEFLECTION RESPONSE CHARACTERISTICS OF A MODEL CONCRETE PAVEMENT SUBJECTED TO STATIC AND DYNAMIC LOADS WITH KNOWN VOIDS PRESENT (RIGID, PUMPING)
Abstract
This study addresses the problem of locating voids beneath rigid pavements. Numerous void detection methods were reviewed and two are recommended for immediate implementation. The first, developed by personnel at the Indiana Department of Highways, utilizes the Dynaflect and has been successfully used to reduce undersealing costs since 1980. The second, a method based on falling weight deflectometer deflections, was developed by researchers at the University of Illinois in 1984. Because of the uncertainty associated with all of the current void detection methods, the efforts of this research were directed toward the development of a more reliable calibration approach for the most common deflection-based methods. Results are presented for both a full scale field study conducted with a Dynaflect deflection device and a reduced scale laboratory model of a pavement system. The results of the field study were sufficient to show that Dynaflect deflections are sensitive to the presence of voids. However, neither the in situ pavement properties nor the exact boundaries of the voids created for the study could be quantified. In addition, the influence of the method used to create the voids was an identifiable and prominent factor in the behavior of the test pavement. A detailed description is given for the design and fabrication of both the model pavement system and the loading devices necessary to model static, harmonic, and impulsive testing procedures. Transducers and data acquisition systems are discussed in terms of the requirements for the three test types. Results verifying the validity of laboratory modeling of pavement systems are presented along with a discussion of difficulties that arose during the study. Suggestions for improved modeling techniques are given.
Degree
Ph.D.
Subject Area
Civil engineering
Off-Campus Purdue Users:
To access this dissertation, please log in to our
proxy server.