Table 4 Lower, upper and medium values of design variables.

1

T _max (°C)

For all cases, T _{r (=20)}

40 for T _max = 40

10

50 for T _max = 50

15

60 for T _max = 60

20

2

S (MPa)

21 for \( f_{{{\text{cd}}}}^{\prime }\) = 30

28 for \( f_{{{\text{cd}}}}^{\prime }\) = 40

35 for \( f_{{{\text{cd}}}}^{\prime }\) = 50

30

40

50

25.5

34.0

42.5

3

t _e (h)

For all cases, 3

12 for t _f = 12

4.5

14 for t _f = 14

5.5

16 for t _f = 16

6.5

18 for t _f = 18

7.5

4

k _a (°C/h)

For all cases, 0

For all cases, 20

For all cases, 10

5

k _d (°C/h)

For all cases, - 20

For all cases, 0

For all cases, - 10

6

T _its (°C)

40 for T _max = 40

50 for T _max  = 50

60 for T _max = 60

For all cases, T _its

10

15

20