Task at Hand
To provide an alternative, reliable transportation system to Jammu & Kashmir, the government of India planned a 272 km railway line joining the Kashmir Valley with the Indian Railways Network under the Udhampur–Srinagar–Baramulla Rail Link Project (USBRL) — a large number of tunnels and bridges through highly rugged Himalayan terrain.
The T-48 tunnel, India’s third-longest railway tunnel at approximately 6.3 miles, comprises a single-track main tunnel of about 40 m² internal section with a parallel 18.4 m² escape tunnel. Excavation was by mechanical breaking and drill blasting, with a dual lining of initial shotcrete plus a final cast-in-place layer. After evaluating site conditions and drilled cores, required values were not reached in certain sections — so a specific shotcrete reinforcement or inner lining had to be applied.
KingKrete Solution
An alkali-free liquid accelerator for wet-mix sprayed concrete, proposed for its setting-time reduction, early compressive strength gain, lower surface dust and rebound rate, and applicator safety versus traditional alkaline accelerators. Sprayed trials determined the optimum dose; applied on-site, it improved shotcrete bond strength and anti-sagging performance while increasing primary spraying thickness and reducing material waste.
An environmentally friendly, high-performance superplasticizing admixture based on polycarboxylic polymers — the ideal choice for a mix with enhanced rheology and cohesion. It provided superior flow and workability while maximizing strength through a lower water/cement ratio; excellent shotcrete was achieved without additional water, superplasticizer, or retarder.
Products & Quantities
| Product | Quantity Supplied |
|---|---|
| KingAdd 25AF | 500,000 kg (94,000 gallons) |
| KingMix 300PC | 200,000 kg (48,000 gallons) |