Pavement Remediation

Pavements not only suffer slab alignment problems, but slab movement also causes –

• Spalling
• Broken edges at expansion joints
• Cracks
• Expansion joint failure

Uretek India has the solutions for all the above problems.

Concrete slabs on runways often break across their corners. This is because the inter-slab expansion joint sealant at the 4-way intersection is stressed and weakens over time, allowing ingress of water. When this happens, the sub-base &/or soil underneath the intersection gets wet and the dynamic loads from aircraft on the slab causes movement and “pumping”.

The moving slabs begin to compress the wet soil, and the pumping moisture washes the soil bit by bit up the open inter-slab joint. Over time the fines are removed in this manner from under the slab and the slab becomes unsupported which results in more movement and voiding from 2 to 30mm under the 4 slabs at the intersection.

With no corrective action all 4 of the slabs will then break at this location. Often one or two corners can be seen to be broken. One or more broken corners indicate that the associated slabs are in danger also as invariably they will be voided as well. The costs of re-supporting them before they are broken is minimal and we strongly recommend this to save time and costs.

The expense and inconvenience of slab replacement can be avoided if the Uretek India Slab Maintenance Program is utilized to do proactive preventative maintenance. Using non-destructive testing Uretek India can identify the locations of voids, before they show on the surface as damaged, cracked concrete slabs.

Once a void is identified, Uretek drills 16mm holes through the concrete of the affected area and investigates the soil strength below. Depending on what we find, we will either underseal the concrete – compressing the surrounding soil, filling any nearby voids and lifting the slab back into place — OR— we will Deep Inject, perhaps as deep as 2 meters to strengthen weak ground, and then underseal as required.

Uretek uses Laser leveling equipment during the process, confirming the progress of the job with string lines and dial gauges. In most cases, a near perfect level can be obtained. Occasionally as concrete slabs rise, they bind against each other, and at this point additional work may be required to achieve a perfect result.

Of course, this work is only the start of the story. Once the slab has been re-leveled, it is vital to ensure that any cracks and inter-slab joints are correctly sealed to prevent further water ingress. In addition, broken slab edges and spalled areas will need correct reconstruction to make the area serviceable “as new”.

Uretek India has the expertise and the technologies to affect all the necessary slab surface remediation in addition to the restoration of the structural support and lifting and realignment of the pavement slabs. All repairs can be carried out in overnight shuts allowing normal aircraft movements.