Volume 20, Issue 2 (March 1992)
Field Evaluation of Pavement Instrumentation Methods
Full-scale testing was conducted to compare the performance of different in situ instrumentations used in flexible pavement, including strain gages, pressure cells, geophones, and single-layer deflectometers. Two test sections were instrumented: one thin section (15.2 cm [6 in. thick]) and one thick section (25.4 cm [10 in. thick]). Each section is 15.2 m (50 ft) long. The testing variables included pavement structure, load, tire pressures, and speed. The criteria for evaluation of performance of the instruments included survivability, repeatability, reliability, the effect of test variables, ease of installation, and data processing. The measured response under different conditions was compared with the calculated response using a multi-layered elastic model. Falling weight deflectometer (FWD) testing was used to quantify the in situ material properties needed for the computer model.