*2.2. Mix Proportions*

In total, five mixes of concrete were cast. The first mix was a control mix with 100% OPC. The remaining mixes contained OPC with at varying percentages of FA and UFFA. The amount of UFFA was kept constant at 10% based on previous studies [17–19]. Details of mix proportions are shown in Table 2. The water–binder ratio was kept constant at 0.35 for all the mixes. A polycarboxylate-based superplasticiser was used to maintain a constant workability (slump = 100 (±5) mm). Due to high fineness of UFFA, the water demand in the mixes increased with the increase in the quantity of UFFA. Therefore, to balance the water demand, it was needed to use higher quantity of superplasticizer as the UFFA content in the mixes increased. The target strength of control mix was 35 MPa at 28 days.



 SP: % by mass of total binder.

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