The challenge
At completion, New Doha International Airport (NDIA) was the second largest airport in its region, with two of the longest commercial runways in the world. The project also included a road network linking the airside and landside facilities, the terminal, and the commercial and midfield areas. The driveways and taxiways were built with plain cement concrete (PCC) pavement slabs on a granular subbase or subgrade. The PCC used aggregate, ordinary Portland cement and water. Admixtures were needed to adjust workability, setting time, strength and durability. All mixes were tightly specified for durability and mechanical strength.
The DCP solution
A PCC with a low water to cement ratio was chosen. DCP used Flocrete SP33 and Flocrete R50 water reducing superplasticisers to speed early strength and give enough flexural strength for loaded aircraft. Flocrete R50 also acts as a retarder, which offsets the effect of hot weather on setting time, cuts slump loss and extends workability. Cemairin 260, an air-entraining admixture, was added to improve durability and workability. It gives greater resistance to freeze-thaw and de-icing agents and reduces sulphate and alkali reactivity.
DCP products used
How it was applied
- Run trials at the DCP R&D centre to set the optimum doses of Flocrete SP33, Flocrete R50 and Cemairin 260 for cost and performance.
- Batch low water to cement ratio PCC with the water reducing superplasticisers.
- Use Flocrete R50 to extend workability in hot weather.
- Add Cemairin 260 for air entrainment and durability.
