. /

1-

2-

3-

4-

5-

6-

7-

== <

. 1928 .

1939

.

.

: . 1928 .

. 1939 .

.

. .

(Partial Prestressing Concrete) . ( ) (DL; LL) ( 1). : 1- (Pre-tensioned) ( (Prestressed steel) ( . ( 2). ( 220/2) (Bond). 2- (Post -tensioned) . (Ducts) ( 250/2) ( 3). (Shear strength) (Continuos elements). (Bonded Tendons) (Unbonded Tendons). (Hydraulic jacks) . (Expanded cement) (Self prestressing) 3-4% . . (Full prestressing) (DL+LL) (Modulus of rupture) ( 4). (Partial prestressing) ( 5) (). (Partial prestressing) (deflection) . (Ductility) (Dynamic and repeated loading). ( )

1. : . ( ) . .

2. :

. . .

3. :

4. : . .

tendon

pre tension concrete strand Grider

Pre Tension concrete slab hollow core slab

Pre tension hollow core slab

Ponded post tension slab

duct

Unponded post tenstion slab

strand PVC

Post Tension Slab =PST Punshing shear shear studs

Steel Shear Studs Punshing shear

1. 2. .3. .4. .5. .6. .7. .

:

1-- : 60-75 . 2-- : .3-- : 12-18 .

:

1-- 2-- .3-- 4-- .5-- .6-- .7--

. . ( ) . . : unbonded .

.

. . . . . lintels. . . ( ). . . . ( ) . . ( ) . . falsework . unbonded :1. destress .2. '' .3. .4. / .

. ( ) . . destress ( ). :1. ( : 4 2 ).2. .3. . () ( ) . . . . . . . . . . . . 1. 2. 3. 4. 5. 8. 9. 10. Post-Tensioning-Cables-13.jpg11. 12. formwork

. Unbonded . [3] . ( ) . floorspace . . 1951. . .

grc

grc 30 . grc .

grc:

1- .2- .3- .4- .5- .6- grc 612 .7- .8- grc .9- 10-

:

()