Application of Whitetopping Technology for National Highway Rehabilitation and Strengthening

The Ministry of Road Transport & Highways (MoRTH) issued guidelines on the application of Whitetopping Technology (WT) for the rehabilitation and strengthening of National Highways, vide circular dated October 3, 2024.

These guidelines recommended Thin Whitetopping (TWT) as the preferred pavement rehabilitation method, with implementation to begin immediately.

Previously, bituminous overlays had been predominantly used for pavement rehabilitation on National Highways. However, this approach had proven limited in lifespan and durability, particularly in regions with high rainfall. The introduction of TWT aimed to address these issues by reducing maintenance frequency and extending the lifespan of pavements, in alignment with Indian Roads Congress (IRC) standards.

The guidelines covered the following key areas:

• Preferred Treatment: TWT was recommended as the most suitable WT technology for National Highways, given its moderate thickness and extended longevity. Ultra-Thin Whitetopping (UTWT) was not recommended for such applications.
• Selection Criteria: Only certain sections of National Highways met the criteria for TWT application, including those sections not expected to undergo capacity expansion within the next 20 years or those located in bypassed, de-notified, or protected areas. Sections with controlled surface disintegration and specified rut depth levels were also prioritized for TWT.
• Construction Standards: The design and construction practices for TWT were required to adhere to IRC guidelines (SP:76). Specific standards included pre-overlay repairs, leveling, temperature control during concrete overlay, fiber addition to prevent shrinkage cracks, and comprehensive curing processes to ensure long-term durability.
• Implementation: Highway authorities and public works departments were directed to incorporate TWT in areas where the technology’s benefits would be most impactful. The focus was on sections with high durability demands, prioritizing environmental compatibility and the enhanced longevity provided by TWT.

Through these guidelines, MoRTH sought to promote TWT as a standard practice to improve the durability, sustainability, and safety of National Highway pavements while reducing life-cycle costs.