Four job sites, four contractors, four German states, one paving method: Dual-layer concrete paving with the slipform paver SP 1500 from Wirtgen is on the road to success in Germany. Swayed by the numerous economic and technical advantages,method statement for asphalting more and more planning engineers are opting for this technology when rehabilitating concrete highways.

Attentive observers will notice that dual-layer concrete paving is currently being used in the rehabilitation of many German highways. This is because noise-reducing non-skid exposed aggregate concrete pavements can be placed most economically with this method. The concept: Bottom-layer concrete is paved on a high-grade subbase with a high load-bearing capacity. This layer is normally 20 – 24 cm thick. It is overlaid with a top layer of exposed aggregate concrete which is normally between 5 and 8 cm thick.intelligent asphalt paver offer

The slipform paver places the two concrete grades wet-in-wet in a fully automated process. The requirements in respect of compressive strength, bending tensile strength and indirect tensile strength are the same for both the bottom layer and the top layer of exposed aggregate concrete. The composition of the concrete can, however, differ with regard to the grading curve,vibratory drum roller sevilla maximum aggregate size, cement content and requirements to be met by the mineral aggregate. While around 350 kg cement suffice per m³ in the bottom-layer concrete, 420 kg cement per m³ are required in the top layer of exposed aggregate concrete.

Coarse aggregate, i.e. material > 2 mm in size, is particularly important in the top layer of exposed aggregate concrete. Only double broken and double screened chippings which meet high demands in terms of angularity,hot asphalt pavement recycling equipment manufacturer grain shape and resistance to polishing are used in order to ensure that the concrete surfacing retains its noise-reducing properties and remains skid-resistant and durable in the long term.