Full-Scale Testing of Pavement Response by Use of Different Types of Strain Gauges

Abstract

From 2002 to 2004 the COST action 347 (European Co-operation in the field of Scientific and Technical Research) was organized under the title “Improvements in Pavement Research with Accelerated Load Testing”, including full-scale pavement tests at a number of European research laboratories. In Lausanne, Switzerland (EPFL) a test pavement of a fullyflexible type was constructed and equipped with strain gauges of different types usually in service in Europe. The loading-facility in Lausanne is an indoor test-pit where road structures can be repeatedly loaded by a linear heavy-pavement-rutting-tester. Within the ALT-program the loading conditions were controlled, comprising a variation of the pavement temperature, a variation of the loading parameters (axle load, tire type and tire pressure, loading speed) and an investigation of the lateral distribution of the responding strains with respect to the load axis. Longitudinal and transversal signals were recorded, that resulted from measurements on the different types of strain gauges and in two different depths: 40 mm and 220 mm from the pavement surface. As a result the shape and the order of magnitude of strains were found for different levels of observation and for defined loading conditions. This makes it possible to
comparatively analyse the functionality of the different types of strain gauges on the one hand, and, on the other hand, to derive important information on pavement response that may
be used in pavement modelling and performance prediction.