Motivation

Test methods currently available provide only limited information about the structural condition of roads. In particular, there is a lack of non-destructive methods that can provide insights into the mechanical properties and the layer structure beneath the surface. This makes it difficult to plan maintenance measures effectively and often leads to the inefficient use of resources.

The goal of this research project is to develop an opto-acoustic measurement technique that can be used to assess the structural condition of roads in a non-destructive, comprehensive, and cost-effective manner. This is intended to enable a significantly improved evaluation of road structures and a more precise prediction of their remaining service life.

The method is based on the targeted excitation of acoustic waves in the pavement structure using high-energy laser pulses and their subsequent measurement. By combining modern measurement technology, signal processing methods, and physical modeling, conclusions can be drawn about material properties and layer structures. This is supplemented by validation through established testing methods and integration into existing road maintenance management systems.

The methods developed enable a new level of quality in the assessment of road infrastructure condition. Public contracting authorities and infrastructure operators thus benefit from more informed decisions regarding rehabilitation measures, a more efficient use of resources, and an extended service life for traffic areas. In the long term, the method therefore contributes to a more sustainable and cost-effective development of infrastructure.

Objectives

The detailed project objectives include:

• the experimental and theoretical advancement of the opto-acoustic measurement method for the comprehensive, structural characterization of mechanical state variables in bonded pavement layers of the road superstructure
• the layer-by-layer separation of acoustic signal information in complex, multi-layered pavement structures through the analysis of dispersive surface waves using mechanical finite element models
• adapting the experimental setup and the laser-induced signal excitation to real-world infrastructure and road conditions, as well as developing a reproducible, high-speed data acquisition system
• the integration of measurement results into existing forecasting and testing procedures to determine and classify the condition and remaining service life of bound pavement layers

Project Partners

The project is coordinated by Uhlig & Wehling GmbH and implemented in collaboration with partners from science and industry:

• der Gesellschaft für Akustikforschung Dresden mbH (AED),
• der SINUS Messtechnik GmbH,
• der Institute for Lasers of University of Applied Sciences Mittweida as well as
• dem Institute for Urban Planning and Road Construction of the University of Technology Dresden.

Support

The research project “Development of a Non-Destructive In-Situ Testing Method for the Bound Layers of Road Pavements Using Opto-Acoustic Measurement Technology – ZOPAS” is co-funded by the European Union and the Free State of Saxony.