Client: Oxfordshire County Highways through a Main Contractor

Site: A dual carriageway bypassing Witney in Oxfordshire. Surface is 20mm Hot Rolled Asphalt

Problem: Fretting of centre line seam joint. Potential motorbike ‘stuck in a rut’ accident due to poor compaction of HRA at edge of each strip.

Solution: Jointmaster rebated repair 200mm wide by 20mm deep and some 50mm deep infill patches.

Facts and Figures

• 4,000 Lin.m of 200mm wide x 20mm deep

• 1.4m³ at 50mm depth

• Lane closure between 9.30am and 4pm

Client: Hull City Council through PBS Construction 

Site: Dual carriageways leading into the centre of the City. Surface; 40mm HRA over 40mm base course. Sub-base; C30 lean mix . Scheduled for surface dressing.

Problem: Reflective cracking from the sub-base and fatigue cracking in the wheel track.

Solution: Jointmaster rebated joint repair 200mm wide by 40mm deep combining BBA HAPAS approved 20mm flexible crack repairs with 20mm 'H’ grade base layer for high stress situations.

Facts & Figures

• 13,000 Lin.m of 200mm wide  x 40mm deep
• Carried out under lane closures between 9.30am & 3.30pm

The installation of Jointmaster is carried out by crews who do this task every working day and have become very accomplished at it. A smooth, quick and efficient operation awaits you when you see a Jointmaster crew.

The A11 Wymondham by Pass is a busy dual carriageway with a CRCP (continually reinforced concrete pavement) construction. Linking the A14 with Norwich, this site is one of the main routes through East Anglia for freight transport between London and the sea ports.

The design of the CRCP had envisaged cracking but over time, some cracks had interlinked with resulting failure of the concrete surface.

Rhino Asphalt Solutions installed the BBA HAPAS approved Jointmaster system to repair the concrete surface to a depth of 40mm in a variety of patches and cracks both transverse and longitudinally.

Selected as a key partner on the M20 Operation Brock project, Rhino Asphalt Solutions Ltd provided a range of critical repair solutions to enable the additional width of carriageway utilising the hard shoulder in the event of contra-flow

BBA/HAPAS approved Jointmaster was the chosen product that due to the unique flexibility, withstands the movement of the concrete pavement without the need to re-form expansion joints. Repairs to bay corners, mid-bay cracking, thin bonded repairs and bridge transition joints were all treated with this process.

Our BBA/HAPAS approved Ironmaster Manhole and gully repair process was used to replace much of the carriageway ironwork ensuring that the hard shoulder could be trafficked with confidence

Rhino Asphalt Solutions installed the BBA HAPAS approved Jointmaster system to repair the fretted longitudinal seam joints in the asphalt mat. This left a safe running surface for traffic and maintained the integrity of the surface.

As an ongoing project to upgrade the M90, the existing overlaid concrete pavement is being resurfaced to improve ride quality, and reduce regular maintenance ‘call-outs’ caused by deteriorating   reflective cracking in the asphalt surface. With the old wearing course material removed, it was evident that prolonged exposure to the ingress of water had allowed the underlying concrete joints to spall. The damaged joints needed repairing before the new surface could be applied over a 4 year programme of renewal.

Rhino Asphalt Solutions installed the BBA HAPAS approved Jointmaster system to repair the fretted longitudinal seam joints in the concrete surface. This left a safe running surface for traffic and maintained the integrity of the surface.

Opened up seam joints between asphalt mats cause a problem because of;

·    Aggregate loss at the interface joint

·    Opened up longitudinal joint

·    Potential motorbike ‘stuck-in-a-rut’ hazard

·    Future pothole formation likely

1.       Cold seam joints

One seam of hot asphalt laid against a second seam of cold asphalt will result in a cold joint interface where the asphalt bond will be less than ideal

2.       Compaction

Lower levels of compaction at the edge (along the seam joint) are likely as the asphalt cools more quickly at the edge making appropriate compaction levels more difficult at this point

3.       Unsealed joint

Where a sealant is not used between asphalt seams then the bond is not as strong as it could be, and a weak point is created.

Left unchecked, this can result in fretted joints, potholes and a resultant safety hazard to motorcyclists.

Jointmaster solves this problem by 

• Sealing the joint
• Reprofiling the surface
• Providing a skid resistant finish  
• Recreating the safe running surface
• Protecting the rest of the asphalt joint structure
• Allowing the surface to last through to its design life
• Maintaining the value of the asset

Asphalt overlays need protection from the shortcomings of the surface upon which they are laid. All too often, the life of the new asphalt is greatly reduced by the cracks propagated from the joints or faults in the underlying surface. This then allows water and salts to penetrate and the rapid deterioration of the surface asphalt begins.

It is becoming increasingly common for an anti-crack membrane to be installed before laying new asphalt to reduce this problem.

Cracks in the highway emanate from either;

1. The surface, where the surface course is fatigued by the traffic

2. The sub-base, from movement of the underlying layers

Stress Absorbing Membranes are used when reflective cracks are showing through from layers below the surface, known as reflective cracking.

Whether the wearing course layer is removed and replaced or simply overlaid, movement in the sub-layers which created the cracked surface in the first instance will, without some form of treatment, create new cracks in the new surface. This cracking will propagate at a rate of approximately 1 year for every 25mm of wearing course applied.

Treating the cracks with a Stress Absorbing Membrane prior to overlay, provides the following benefits:

• Seals the cracks against further water ingress

• Bridges the crack, shifting the concentration of movement across a larger area, minimising its impact

• Increases the time until reflective cracks will show through the new surface

• Keeps water out of the sub-structure for longer

Jointmaster is a polymer modified, rubberised bitumen compound containing glass fibre reinforcement. The compound is applied as a molten screed directly over the cracks and joints in the surface prior to being overlaid. It fills and seals the cracks in one pass, leaving a membrane focused solely at the point where the movement is concentrated. This systems offers savings over full surface membranes as the material is laid only at the points where the movement is causing an issue.

Concrete surfaces which have been overlaid with any variety of asphalt layers will typically fail when the asphalt cracks above the location of the concrete joints.

The reason for this common failure mode is that asphalt cannot cope with the large amount of movement concentrated at the bay joints. Or, in the case of CRCP concrete, at the point above the cracked CRCP.

Left unrepaired, this crack will become larger as traffic pounds water into the crevices until it eventually becomes large enough to be a pothole. 

These open joints are often associated with the ‘b-bump’ noise as vehicle tyres drop into and climb out of the degraded joint.

Repairing these failures can be easily achieved using BBA HAPAS approved Jointmaster repairs. A typical repair would need to be deep enough to cut into the concrete surface underneath, so typically 40mm or 50mm deep. The width would be determined by the width of the crack. Jointmaster is installed by cutting a rebate necessary to remove all failed material. This could be 200mm or 300mm wide and sometimes larger.