High Strength Concrete
The design approaches given in the now superceded codes such as BS 8110 and BS 8007, were based on ‘normal’ concrete strengths. In BS 8110 these are generally a maximum of 40 N/mm2 for reinforced concrete and 50 N/mm2 for precast concrete (both values are cube strengths).
However, higher strengths are regularly achieved in some applications, particularly when the concrete is designed to give a very high early strength or when very high level of durability is required. Such concretes are outside the scope of BS 8110. However, the principles involved in the design of elements such as beams and columns are still applicable, but some modifications are required linked to the higher concrete strengths.
Concrete Society Technical Report 49, ‘Design guidance for high strength concrete’ contains appropriate design methods that are valid for concrete strengths up to 100 N/mm2, along with appropriate column design charts.
The design methods in Eurocode 2 are applicable to concrete with a cube strength of up to 100 N/mm2.