CAVITY DRAINAGE LAYER

▪ Control of reflective cracking

The use of Rotaflex in reflective-crack prevention extends pavement service life up to 10 times. Rotaflex provides reinforcement to prevent crack propagation and enables the overlay thickness to be reduced. Rotaflex is compatible with modern thin asphaltic concrete overlays.

▪ Thermal fatigue (concrete roads)

The thermal movement of the concrete pavement results in contraction and expansion at the construction joints. A regulating course is normally required. Rotaflex is laid to reinforce the new overlay to prevent or retard cracking.

▪ Widening and haunching

A major problem in road widening schemes is that the new and old pavement structures tend to move apart due to differential settlement and thermal movement. By reinforcing the joint with Rotaflex the harmful effects on the final surface can be virtually eliminated.

Rotaflex Glass Fibre

Glass fibre is both strong and flexible. It is thermally and chemically stable at bituminous mix temperatures of 200°C. It is not affected by de-icing salt, petroleum or bitumen and has a thick polymer coating for mechanical protection. Glass fibre provides maximum strength even at very low strains. This is important because un-reinforced asphalt will crack at strains as low as 1%. Glass fibre has a Young's Modulus of 70GPA (20 times that of asphalt) which means that it provides effective reinforcement. Rotaflex provides reinforcement throughout the asphalt layer and so its performance is unaffected by subsequent service trenches.