Abstract:
Currently, the amount of fly ash discharged from Duyen Hai 1 and 3 Thermal Power Plants is about 2 million tonnes annually. Therefore, the handling of a large amount of fly ash requires practical and urgent actions to be taken. The article presents the results from studies using fly ash content from the Duyen Hai 1 Thermal Power Plant to replace cement in the composition of M400R28 concrete with a slump of 12±2mm. M400R28S12 concrete with 100% of sulphate-resistant cement – PCsr40 durable cement was included in the experiment proportioning and, in turn, levels of fly ash at 20%, 30%, 40%, 50% were calculated. The results show that when using up to 50% of the fly ash over the total binder mixed with the premium superplasticiser and maintaining a long-lasting MC-PowerFlow 2257P, the actual requirements of concrete hashes such as flexibility, time to maintain the necessary slump and time of the retarding are still satisfied. Compressive strength (Rn), bending strength (Ru), water permeability and chloride ion absorbent sample still meet the technical requirements