Rehabilitation of National Highway at Tripura-Assam

Location: National Highway - NH-44, Churaibari, near the Assam-Tripura border
Principal Client: PW (Building and NH) Department Government of Assam
Main Contractor: ABCI Infra
Application: Rehabilitation of damaged section of NH-44
System Offered: Pavement section incorporating StrataWeb®

The Project

The National Highway NH-44 is a major road artery for the North-East. The stretch of this highway leading to the border of Assam and Tripura (two states in the north-east of India), is the only land-link between Tripura and the rest of the country. NH-44 is the state’s life-line for supplies and victuals, and all commercial activities.

The Challenge

The subgrade of the highway is highly plastic, weak, clayey soil. There was heavy rain in March 2016, which damaged this stretch, as shown in the pictures. Conventional repairs were attempted which were unsuccessful in allowing smooth traffic across this 500m stretch. With the bottleneck of stranded vehicles, the situation turned chaotic and untenable causing blockage of all goods to Tripura and isolation from the rest of the country.

The issue escalated to the Central Government because the prices of essential commodities including fuel and food hit the roof. In view of Strata’s known expertise in geosynthetics and pavements, the Assam Public Works (Buildings & NH) Department consulted with Strata.

Strata’s Innovative Approach

There were two essential issues to be addressed:

1. Drainage of the pavement section and its subgrade
2. Strengthening the pavement section.

Strata recommended StrataWeb® within the pavement section to solve both these issues. With a CBR (California Bearing Ratio) as low as 0.5% and a traffic of 20MSA (Million Standard Axles), the following section was proposed by Strata:


The Rehabilitation

At first, the remnants of the existing road were scrapped off. The subgrade was then dressed, levelled and compacted. A non-woven geotextile was placed above the compacted surface to prevent intermingling of the engineered section with the weak plastic subgrade.

The highway opened to all traffic immediately after the granular base was laid. The bituminous concrete and the dense bituminous macadam layers were placed later.

It has been candidly acknowledged by the Assam PW (Buildings and NH) Department, to quote:

The NH-44 at Churaibari once became infamous for mud and slush, is now transforming into heaven of beauty. All this has been made possible by the use of Geocell in road construction.

Strata’s Value Addition

• Ensured smooth traffic in record time when conditions were distressing
• The pavement was strengthened compared to the conventional section
• Reduced maintenance cost and
• Increased road life-span significantly.