Publication Details
Instrumentation for Flexible Pavements - Field Performance of Selected Sensors 
Primary Topic: Flexible Pavement
Description: This report presents the results of a research study on methods for measuring strain and stress in bituminous pavements subjected to dynamic vehicle loading. The research program was divided into two phases. In the first phase, an extensive literature search was conducted to identify the existing pavement instrumentation and to select the most promising types of gauges for a field testing program. Two sections of bituminous pavement 6 and 10 in (152 and 254 mm) thick were constructed and instrumented with the selected gauges. The response of the gauges to dynamic loading applied by a tractor-semitrailer at different levels of axle loading, tire pressure, and speed was investigated. In the second phase, new concepts in pavement instrumentation were investigated. Prototype gauges were built and evaluated, first in the laboratory and then in a field testing program similar to the one conducted in the first phase. Two new gauges, an inductive sensor and the Hall effect sensor, performed very well in the tests. The pavement response data, collected in the field testing program, were used to evaluate methods for backcalculating pavement material properties. It was demonstrated that the backcalculated moduli are much more accurate if data from multiple sensors placed throughout the pavement structure, rather than a single sensor measurements, are used in the analysis.
FHWA Publication Number: FHWA-RD-91-094
Publication Year: 1992