07/08/2026
Can a 100 mm Bitumen Stabilised Material (BSM) layer utilising 100% Reclaimed Asphalt match the structural performance of a mix blended with virgin aggregate?
A 3.3 km Cold In-Place Recycling (CIR) trial on a single-lane dual carriageway northeast of Kiel, Germany, evaluated two recycled material compositions under real-world field conditions.
Working over an existing 100 mm asphalt layer on a granular base, the project evaluated two structural formulations:
- Section 1 (1.1 km): 100% Reclaimed Asphalt (RA)
- Section 2 (2.2 km): Reclaimed Asphalt blended with 0–16 mm crushed stone
Cement was applied prior to recycling. The reclaimed materials were processed using a Wirtgen W240 CRi cold recycler, paved with a Vögele Super 2100-5i, and compacted using Hamm tandem and pneumatic tyre rollers to produce the BSM layer. The section was then surfaced with a 60 mm asphalt binder course and a 40 mm wearing course.
Loudon International provided technical support throughout the trial, focusing on construction monitoring, process optimisation, and technical collaboration between Strabag, Wirtgen GmbH, and the Schleswig-Holstein State Road Authority (LBV.SH).
