Sarandily - BSc PhD CEng MIMarE , Principal Structural Engineer, Babtie BMT Harris & Sutherland, Hong Kong

Underwater concreting plays an important role in the construction of offshore structures. This paper describes the development and design of an underwater concrete mix. Underwater concreting is normally camed out through a tremie tube. This operation is called the placement of tremie concrete, which is not cost effective and may not achieve the design criteria. In recent years, however, increased commercial interest has led some companies to develop admixtures, which when added to normal concrete mix design allow the concrete to be placed underwater without using tremie pipes. This means that concrete can be pumped or dropped under water without segregation whilst still achieving normal cube strength. This paper discusses in detail the development and design of an underwater concrete mix by the author whilst working at King's College London. The paper also discusses how various admixtures were selected.