How to bring a highly map cracked road surface back to acceptable performance levels
Today, more than ever before, our economy is faced with an unprecedented slow down. As a result, Government revenues are severely impacted, having to cut programs and squeeze budgets in favour of the most critical of public interests; maintaining roads usually doesn’t make the cut.
We have a high number of roads that fall into disrepair (even before the Pandemic) for a variety of reasons. One of the typical behaviours of road is to Crack. There is one type of cracking in particular that we are addressing in this article; Map Cracking. This is typically the result of poor binder selection.
Figure 1. Top view of distressed section
Figure 2. Long view of distressed section
As the name indicates, Map Cracking is a highly dense network of cracks on the pavement’s top surface. The key phrase being ‘network of cracks’; all these cracks are interconnected leaving behind small island-like formations. The severity is measured based on number of occurrences/square meter area.
The primary threat of this condition on the road is easy and high levels of water ingress. Water ingress is a term characterizing water seeping through the road top layer into the base of the road; this can lead to various issues such as settlement (in case of improper base preparation) which ultimately necessitates full construction to repair the pavement.
There are various solutions used in the industry to address such kind of distresses, some of which are outlined below;
- Crack Sealing with BE3100 CrS Bitumen Emulsion – this involves a manual effort in filling the cracks with emulsion. Even though this is not advised for map cracking because of speed of work, some contractors prefer to use this,
- Sand Sealing with BE3100 SaS Bitumen Emulsion – this involves manual effort in spreading emulsion on the cracks and then sprinkling sand on the emulsion. This is not advised for map cracking solutions on high speed roads because of the smooth surface after, leading to potential skidding.
Both these solutions offer highly varying results, even when applied by the same team and batch materials. This can be chalked up to the high level of manual intervention required that inevitably compromises on consistency in work quality.
The ground breaking new solution; ScratchCoat™ Crack Sealing can help seal these cracks and extend the life of the pavement all while ensuring safety of the road users!
So what is ScratchCoat™?
ScratchCoat™ is a unique form of slurry sealing where the slurry; which is a blend of a specially graded aggregate dust mix and a highly tailor-made BE3100 ScC Bitumen Emulsion and other fillers and additives, is forced into the cracks to fill the gaps and bind the “islands”. There is an extremely high bitumen content in the resultant mix of up to 8% ensuring negligible voids in the filling thereby minimizing further any risk of water ingress.
The treatment is developed as a method to ensure quality and speed while maintaining uniformity of application and economically maximizing the life of the pavement.
The earlier photos (fig. 1 and 2) are from a highly distressed section of the Ghaziabad-Aligarh Section in Uttar Pradesh.
An ultrathin later is scratched onto the surface of the road, adding nil to negligible height to the road level and ensuring that maximum slurry is pushed into the cracks and filling up the gaps.
During ScratchCoat™ –
Figure 3. Before application
Figure 4. Section immediately after laying of ScratchCoat™
In Ideal working conditions each machine can do up to 10,000 sqm. a day; that’s almost 3 lane kms a day!
Subsequently as the slurry sets, one can see in the image below (Fig. 5) a slight reminiscence of cracked surface characterized by the slight but sealed depressions in the location where the canyon was, indicating the history. But the crack is sealed preventing any further potential distress to develop in the sector.
Although the pavement is now more comfortable to drive on, for a longer lasting surface with a better ride quality and skid resistance, we highly recommend an overlay of Microsurfacing.
Figure 5. Before Microsurfacing application
Figure 6. Surface immediately after overlay of Microsurfacing
Figure 7. After 1 month of finishing the surface
Figure 8. After 3 months of finishing the surface
This is the same section (fig.7) with the work completed pre-monsoon and the follow up image (fig. 8) taken mid to post-monsoon. The treatment has saved the pavement from significant further distress and a heavier maintenance cost for the concessionaire/government later!
In case you are facing any similar issues on your assets, contact us now!! – micro@arthermosets.com
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Map Cracking is a highly dense network of cracks on the pavement’s top surface which can lead to high levels of water ingress resulting in various types of distress such as base settlement.
How to bring a highly map cracked road surface back to acceptable performance levels?
ART’s ground breaking new solution; ScratchCoat™ Crack Sealing can help seal the cracks in your pavement and extend its life, all while ensuring safety of the road users!