Steel Reinforced Asphalt Layers

Investigations and Experiences in Germany

Abstract

Due to the increase of heavy traffic loading and expenses for road maintenance and rehabilitation a continuous research and development work in the field of innovative pavement and material designs is needed. Aims of reinforcement structures used in asphalt roads are prolongation of service life by increasing bearing capacity and delaying plastic deformations or cracking respectively.
Within the 4th EU-framework the REFLEX-project “Reinforcement of flexible road structures with steel fabrics to prolong service life”, was focusing on benefits and further developments of reinforced asphalt layers using steel fabrics. Dependent on the load and environmental conditions within Europe the research group was focusing on bearing capacity and on resistance against thermal cracking (including frost heave) reflective cracking, plastic deformations and flow rutting. This paper shows the German investigations, results and experiences focusing on flow rutting and bearing capacity:
- Design of reinforced pavements supported by theoretical models (Multi-layer-theory, FEM) to check the performance of net structures.
- Interaction between asphalt and reinforcement structures (bond) as well as performance of reinforced layers by lab tests.
- Monitoring of the behaviour of steel reinforcements during the placing of the asphalt and establishment of recommendations for the design and the construction of such pavements. Measurements performed during the paving process show the sensitivity of this technology (especially for the usage against flow rutting) given by the fundamental material properties of asphalt and steel.
- Monitoring of test sections (especially bus-stops) and road sections.