(binder)( 10~35%)

(fine agg.)

(admixture/

superplasticizer)

(water)

(water)

(cement)

(aggregate)

(coarse agg.)

(admixture)

(air/void)

(cement paste)

(hydration)

(25~40%)(mortar)

(60~80%)(aggregate) 1~6%

(concrete)

1

2

(fcr):, ,

28(f28): 28 28 28, 28

(fa):

, () ,,

3

: fck =(MPa) :

1(1, ) 27 (f28fck)

(fcr)

BS() 150150150mmDIN() 200200200mm

)200100()150150150()200200200()300150( 97.078.083.0 cylcubcubcyl ffff

L/D =2L : 300mm, 200mmD : 150mm, 100mm

D

L

, ,

.

, / ,

,

4

5

Yes

No

?

6

,

(fck)(fcr)

5%, 85% 0.13%

(fcr) 28(f28)

, AE, /(W/C)

(300kg/m3), (260~320kg/m3),(160~220kg/m3),(390kg/m3)

(Gmax) 1/5, 1/3, 3/4

7

(slump) , , : (80~150mm),(60~120mm) : (50~150mm),(50~100mm)

(air content) 4~7% : 4.5% (1.5) : 5.5% (1.5) : 4.5% (1.5) : 3.5% (1.5)

(Gmax) () / 55%, 80mm,( 2.8),

8

: / 55%, 80mm,,( 2.8) S/a (%) W (kg): 0.1() 0.5()

: 1mm() 1.2%(): 0.05() 1()

S/a: 1%() 1.5kg(): 1%() 0.5~1() 3 %()

3~5 9~15 2~3 6~9

: ,,

(mm)(mm)

(%)

W/C (%)

S/a (%)

(kg/m3)

W

C

S

G

25 150 50 38.9 178 356 702 1,120 1(30) 25 150 50 38.9 5.34 10.68 21.06 33.60

28: 24MPa, : 12015mm, : 4.5%,,: 25mm, AE 0.03%

= 3.15g/cm3 = 2.60g/cm3, = 2.65g/cm3 = 2.86, = 7.31

s = 3.6MPa fcr = fck + 1.34s = 24 + 1.343.6 = 28.8MPa fcr = fck 3.5 + 2.33s = 24 2.333.6 = 28.9MPa = 28.9MPa

/ f28 = 13.8 + 21.6C/W 28.9 = 13.8 + 21.3C/W

.. W/C = 0.505 = 50%9

(mm)

(%)

(%)S/a(%)

W(kg)

15202540

7.06.05.04.5

2.52.01.51.2

53494540

202197187177

(mm)

(%)

AE AES/a(%)

W(kg)

S/a(%)

W(kg)

15202540

7.06.05.04.5

47444239

180175170165

48454340

170165160155

2.8, ,/ 55%, 80mm

10

S/a = 42% W = 170kg

11

S/a = 42% W = 170kgS/a W

2.8 2.86

(mm) 80 120 (12 8) 1.2 = 4.8%

- 0.55 0.5

(%) 5.0 4.5 (5.0 4.5) 3 = 1.5%

0.3% +6.3% S/a = 420.3 = 41.7% W = 170 1.063 = 181kg

%...

.. 305010

82862 =

%..

.. 011050

05050 =

%.... 407501

5405 =

(C) = 181/0.5 = 362kg (Vc) = 362/3.15 = 115 = 4.5% = 45 (a) = 1000(115+181+45) = 659 (s) = 659 0.417 = 275 (S) = 275 2.60 = 715 kg (Vg) = 659275 = 384 (G) = 384 2.65 = 1,018kg AE = 362 0.0003 = 0.1086kg = 108.6g

12

= 30(1)/1000

(mm)

(mm)

(%)

/

W/C (%)

S/a(%)

(kg/m3)W

C

S

G

AE(g/m3)

25 1201.5 4.50.5 50 41.7 181 362 715 1,018 108.630 5.43 10.86 21.45 30.54 3.258

13

/(W/C) f28 W/C W/C f28 W/C

W/C(S/a)

)()(

yxGSxSS +

+=100

100)()(

yxGSxGG +

+=100

100

+=100

1 mAA sw100

smAWW =

, S =G = S = G =x = 5mm (%)y = 5mm(%)

, Aw = As =m =(%)W = W =

(KS F 2403, ASTM C192)

1. 2. 3.

4. 5. 6.

14

(KS F 2402, KS F 2594, ASTM C143)

50mm ,

,

15

(KS F 2402, KS F 2594, ASTM C143)

1. 2. 3

3. 4.

16

(KS F 2405, KS F 2433, ASTM C39, ASTM C496)

17

18

(KS F 2408, ASTM C78, ASTM C1609)

ASTM C 78 Third-Point Loading

ASTM C 293 Center-Point Loading

19

(KS F 2408, ASTM C78, ASTM C1609)

20

f

(a) (a)

SFD

BMD

No shear force

(KS F 2408, ASTM C78, ASTM C1609)

21

(KS F 2408, ASTM C78, ASTM C1609)

(Plain Concrete)

() (Modulus of Rupture) ; 2bdPLfr =

0

5

10

15

20

25

30

35

40

0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0Net midspan deflection (mm)

F

l

e

x

u

r

a

l

l

o

a

d

(

k

N

)

22

(KS F 2408, ASTM C78, ASTM C1609)

(Steel Fiber Reinforced Concrete, SFRC)

2bdPLf =