Recycling of Concrete for the Reconstruction of the Concrete Pavement of the Motorway Vienna – Salzburg

From 1991 to 1993 60 km of carriageway were reconstructed on the motorway Salzburg-Vienna, re-using the old concrete pavement 100% on the work-site. The fine material (0/4) that resulted when crushing the old pavement was added to the old granular subbase which without would have been too coarse-grained to be stabilized with cement. The bottom layer (21 cm thick) of the new concrete pavement was made from natural sand 0/4 and the crushed concrete used as coarse aggregate. The cement requirement was about the same as for crushed stone, but the flexural strengths were better than they would have been with most natural aggregates, the reason being the very good bond between the new cement stone and the old high-quality concrete. Asphalt particles originating from thin bituminous overlays did not exceed 10% of the coarse aggregate and had practically no harmfull eftects.