Text Box: Table 2 Effect of a 5% fineness variation on 28 day concrete cube strength (Dhir et al., 1996)
PC+FA content (kg/m3) Rate of strength change per 5% FA fineness variation (N/mm2) Strength range for ±10% BS EN 450 allowance (N/mm2)
250 0.4 ±0.8
350 0.6 ±1.2
450 1.0 ±2.0
550 1.5 ±3.0