Laboratory testing and modelling of axle load sensor–asphalt mixture system

Load sensors are core components of Weighin-Motion (WIM) systems. Since WIM enables continuous monitoring of heavy vehicle loads, it plays a key role in developing smart and digital pavements. A primary limitation of WIM system accuracy is the overly simplified treatment of stresses acting on the pressure sensor under vehicle loads, what causes loss of accuracy over time. This paper presents a laboratory test stand and a dedicated FEM model, both developed to study stress distribution effects on the axle load sensor and its influence on the generated electrical signal. This signal is subsequently processed and converted into the measured wheel load. The experiments demonstrate how the signal varies with sensor position and force application. The findings confirm that stress distribution across the system, including the wheel load sensor and asphalt mixture, cannot be neglected when accurately transforming the electrical signal into wheel load measurements.