White Topping: reusing existing asphalt with TwistR® concrete
A thin concrete layer with TwistR® fibres over existing asphalt: less removal, less new concrete, a slimmer construction and 20+ years of service life.
White Topping is a renovation method in which a concrete surface is laid directly over the existing asphalt construction. The old asphalt does not need to be removed but is reused as the foundation. That saves raw materials, transport movements and CO₂ emissions — and delivers a low-maintenance surface with a long service life. On the cycle paths along the N344 in Barneveld, this approach was used to lay a 12 cm thick concrete layer over the existing asphalt.
Slimmer thanks to fibre reinforcement
The key lies in the fibre reinforcement. TwistR® fibres increase the crack resistance of the concrete, allowing the required concrete thickness to be reduced. The result is a saving on concrete consumption, transport and CO₂ emissions — without compromising the durability or service life of the surface. The fibres also replace the traditional reinforcement mesh, so laying and aligning mesh is no longer required.
Proven on the N344 and the N355
The method has proven itself in practice. On the cycle path along the N344 near Barneveld, reusing the existing construction saved around 2,500 tonnes of asphalt that would otherwise have had to be removed, project costs were reduced by roughly 25%, and the expected service life is more than 20 years. Along the N355 in Friesland, the white topping method was even applied as a European first: a thin concrete layer with TwistR® macro fibres laid directly over the existing asphalt.