Concrete Strength Gain Over Time
Maturity Index: Sum of (Temperature - Datum) x Time intervals
Strength at day t: f28 x t / (a + b x t) (ACI hyperbolic model)
Typical Strength Gain Schedule
- Day 1: 15-20% of 28-day strength
- Day 3: 40-50% of 28-day strength
- Day 7: 65-75% of 28-day strength
- Day 14: 85-90% of 28-day strength
- Day 28: 100% of design strength