ULTRA HIGH STRENGTH CONCRETE

Ultra High Strength Concrete (UHSC) may be defined as concrete with specified characteristic cube strength of 50N/mm2 and above. Strength levels of 50 N/mm2 and even higher are being used for both precast and in-situ works. The main applications for UHSC in-situ concrete construction are in offshore structures, columns for tall buildings, long-span bridges and other highway structures. The main advantage is the reduction in size of compression elements and/or the amount of longitudinal reinforcement required.

The methods and technology for producing high strength concrete are not substantially different from those required for normal strength concrete. The target water/cement ratio will be in the range of 0.30–0.35 or even lower.

Superplasticisers / high range water reducers are used to achieve maximum water reduction. Silica fume (microsilica) or metakaoline can be used to enhance the strength at high levels.