The challenge
Phase 1 of Bengaluru International Airport needed concrete grades from M10 to M50 for substructures and superstructures. The SNF admixture chosen at specification stage was a low end product that only partly met the needs and was used for M10 to M30. The wall panels needed a highly flowable, stable self-consolidating concrete (SCC) with a smooth, fair finish so that plastering could be avoided.
The DCP solution
The DCP technical team proposed an M50 concrete using two grades of its Supaflo SNF range, Supaflo 3 and Supaflo Special, which give high workability and strength. The optimal mix was set after a study of materials and mock-up trials.
DCP products used
Admixtures
Supaflo Special
High range water reducing admixture with workability retention properties Product page: Supaflo Special
How it was applied
- Materials studied and mock-ups made to fix the final mix design.
- Mix for wall panels: cement 330 kg/m³, fly ash 120 kg/m³, free water 180 litres, 100% crushed sand, CA:FA 50:50, 10 mm nominal aggregate.
- Mix designed for 60 minutes retention and 550 mm flow, then the wall panels were cast.
- The same Supaflo M50 mix was used for the prestressed girders of the flyover to the airport.
The result
The panels reached the required final compressive strength in 7 days.
