Table 5 Optimized and modified optimum results.
From: Optimization of Curing Regimes for Precast Prestressed Members with Early-Strength Concrete
Conditions | Optimized result | Modified optimum result | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
\( f_{{{\text{cd}}}}^{\prime }\) (MPa) | T max for 40 °C < T < T max | t f (h) | Design variable | \( \frac{S}{{0.7 f_{{{\text{cd}}}}^{\prime } }} \) | idx (°C · h) | Design variable | \( \frac{S}{{0.7 f_{{{\text{cd}}}}^{\prime}}}\) | idx (°C · h) | |||||||
T max (°C) | t s (h) | k a (°C/h) | k d (°C/h) | Value | r idx | t e (h) | k a (°C/h) | k d (°C/h) | Value | r idx | |||||
30 | 60 °C | 12 | 60 | 12 | 20 | −16 | 1.00 | 270.0 | 0.75 | – | – | – | – | – | – |
14 | 60 | 11.5 | 20 | −16 | 1.00 | 250.0 | 0.69 | – | – | – | – | – | – | ||
16 | 60 | 11.00 | 20 | −16.5 | 1.00 | 231.5 | 0.64 | 14.00 | 20 | –7.4 | 1.07 | 291.5 | 0.81 | ||
18 | 60 | 10.50 | 20 | −16.5 | 1.00 | 211.5 | 0.59 | 13.50 | 20 | −7.4 | 1.07 | 271.5 | 0.75 | ||
50°C | 14 | 50 | 14.00 | 20 | −15.5 | 1.00 | 278.5 | 0.77 | – | – | – | – | – | – | |
16 | 50 | 13.00 | 20 | −19 | 1.00 | 253.0 | 0.71 | 16.00 | 20 | −6.6 | 1.05 | 298.8 | 0.83 | ||
18 | 50 | 12.50 | 20 | −14.5 | 1.00 | 231.5 | 0.64 | 15.50 | 20 | −5.9 | 1.05 | 276.5 | 0.77 | ||
40 °C | 18 | 40 | 14.50 | 20 | −12.5 | 1.00 | 264.0 | 0.73 | – | – | – | – | – | – | |
40 | 60 °C | 12 | 60 | 11.50 | 20 | −14.5 | 1.00 | 244.8 | 0.68 | – | – | – | – | – | – |
14 | 60 | 11.00 | 20 | −15 | 1.00 | 226.7 | 0.63 | – | – | – | – | – | – | ||
16 | 60 | 10.50 | 20 | −15 | 1.00 | 206.7 | 0.57 | 13.50 | 20 | −7.1 | 1.06 | 266.7 | 0.74 | ||
18 | 60 | 10.00 | 20 | −15.5 | 1.00 | 188.4 | 0.52 | 13.00 | 20 | −7.2 | 1.06 | 248.4 | 0.69 | ||
50 °C | 14 | 50 | 13.50 | 20 | −14 | 1.00 | 260.4 | 0.72 | – | – | – | – | – | – | |
16 | 50 | 12.50 | 20 | −17 | 1.00 | 236.0 | 0.66 | 15.50 | 20 | −6.3 | 1.04 | 281.1 | 0.78 | ||
18 | 50 | 12.00 | 20 | −13.5 | 1.00 | 214.2 | 0.59 | 15.00 | 20 | −5.7 | 1.04 | 259.1 | 0.72 | ||
40 °C | 18 | 40 | 17.00 | 20 | −14.5 | 1.00 | 256.2 | 0.71 | – | – | – | – | – | – | |
50 | 60 °C | 12 | 60 | 10.50 | 20 | −17 | 1.00 | 212.9 | 0.59 | – | – | – | – | – | – |
14 | 60 | 10.00 | 20 | −17 | 1.00 | 192.9 | 0.54 | – | – | – | – | – | – | ||
16 | 60 | 9.50 | 20 | −17.5 | 1.00 | 174.3 | 0.48 | 12.50 | 20 | −7.6 | 1.08 | 234.3 | 0.65 | ||
18 | 60 | 9.00 | 20 | −18 | 1.01 | 155.6 | 0.43 | 12.00 | 20 | −7.7 | 1.08 | 215.6 | 0.60 | ||
50 °C | 14 | 50 | 12.50 | 20 | −15 | 1.00 | 232.5 | 0.65 | – | – | – | – | – | – | |
16 | 50 | 11.50 | 20 | −18.5 | 1.00 | 208.2 | 0.58 | 14.50 | 20 | −6.5 | 1.06 | 253.2 | 0.70 | ||
18 | 50 | 11.00 | 20 | −14.5 | 1.00 | 186.5 | 0.52 | 14.00 | 20 | −5.9 | 1.06 | 231.5 | 0.64 | ||
40 °C | 18 | 40 | 16.00 | 20 | −12.5 | 1.00 | 234.0 | 0.65 | – | – | – | – | – | – | |