BRIDGE WEIGH-IN-MOTION MEASUREMENTS ON SHORT SLAB BRIDGES WITHOUT AXLE DETECTORS

Abstract

Some recent research projects introduced the Free-of-Axle Detector (FAD) Weigh-in-Motion (WIM) concept where the most sensitive part of the bridge WIM equipment, the axle detectors on the pavement, are replaced with strain readings from underneath the bridge. This simplifies considerable installation and maintenance and increases durability of the system. The paper presents criteria required for a bridge to comply for FAD installation, research done on short slab bridges, which are easy to find on most road sections, results of the first successful real-time measurements, difficulties to be tackled and work to be done before successful implementation of the procedure.