Massive use of pulverised fuel ash in concrete for the construction of a U.K. power station

This paper describes the incorporation and benefits of pulverised fuel ash (PFA) in nearly 620,000 m2 of concrete used in the construction of the U.K.ʹs first commercial pressurised light water nuclear reactor power station, Sizewell B, Suffolk. Overall nearly 100,000 t of PFA, 1300 t of sintered fly ash lightweight aggregate, and nearly 137,000 t of Ordinary Portland Cement (OPC) were used in the works. Generally in the construction of the main power station buildings, structural concrete with a characteristic strength of 45 N/mm2 was placed and included fly ash as 40% of the cementitious component. Also, concrete with fly ash as 50% of the cementitious component was placed as mass fill. The programme of research is reported, including sulphate resistance, heat of hydration, elastic properties, alkali-silica reaction, and long-term strength test results. Test and field results are presented and discussed. Strict quality assurance procedures were enforced and statistical summaries are offered to give an insight into the quality of control exercised. Test work and long-term results are also outlined.