M4 Junctions 5-7 – IKO Permatrack H

Inlaid crack sealing system

M4 junctions 5-7 is a composite pavement with the construction being made up of 190mm of wet-mix at the base overlaid with 140mm of bituminous surfacing.

The project involved treatment of longitudinal and transverse cracking in lanes 1 and 2 of the carriageway. IKO Permatrack H (High Modulus) Inlaid Crack Repair System was installed as a solution to a reflective crack extending to a length of 6.7km and IKO Permatrack Samiband was used to repair over 3km of transverse cracking in the carriageway.

IKO Permatrack H (High Modulus) Inlaid Crack Repair

The existing surface was planed to the top of the wet-mix layer to a depth of 140mm and to a width of 300mm. After cleaning and drying the excavation was primed before a 5mm layer of IKO Permatrack PSB was applied to the bottom and vertical edges of the joint. IKO Permatrack H was then laid into the joint in two 50mm layers.

The carriageway was reopened to traffic for the following day leaving the IKO Permatrack H as the running layer before being overlaid with 40mm of thin surfacing the following night. Outputs achieved for the IKO Permatrack H inlaid crack repair were between 250 and 300m each night using 32 tonnes of material per shift.

IKO Permatrack samiband

The transverse cracks were treated by planning the existing surface to a depth of 40mm. Prior to the replacement surface course being laid, cracks that were evident were cleaned and primed before a 3mm layer of IKO Permatrack PSB was laid.

Composite Glass-fibre Geogrid was laid onto the still warm PSB to widths of between 500mm and 1m before being overlaid with 40mm of thin surfacing.