Abstract

Under existing concrete highway payments there are voids that develop because of the pumping action of the slabs. The presence of free water, curled slabs from temperature and moisture gradients, and heavy wheel loads combine to provide this problem. The result is pumping and erosion of the base material, nonuniform support of the pavement slab, and eventual breakup of the concrete slabs. Two methods of voids detection were utilized in this study to compare one against the other. The first method used the Falling Weight Deflectometer (FWD) and the second method used the Ground Penetrating Radar (GPR) unit. Deflection readings obtained with the FWD is acquired from seismic sensors mounted on a beam centered under the trailer which allows five deflection points to be utilized. The force is applied to a 150mm (4.92 inches) base plate for a duration 25-30 milliseconds. The second method used a Ground Penetrating Radar (GPR) equipment. The GPR is a non-destructive method in geotechnical investigation capable of surveying large areas quickly and efficiently. GPR works as an echo sounder with a continuous similar graphic display. Cavities are identified by hyperbolic patterns caused by reflections from variations in electrical properties of anomalies as compared to the surrounding material. The intent of this study is to determine those circumstances under which GPR and/or FWD can be used in subsurface void detection investigations. The results indicate that voids detection by these two methods are generally favorable and that these two methods can be very useful in determining voids underneath concrete pavement slabs

Graduation Date

1987

Semester

Fall

Advisor

Kuo, Shiou-San

Degree

Master of Science (M.S.)

College

College of Engineering

Format

PDF

Pages

119 p.

Language

English

Rights

Public Domain

Length of Campus-only Access

None

Access Status

Masters Thesis (Open Access)

Identifier

DP0020588

Included in

Engineering Commons

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