131. TENSIONING EQUIPMENT
C System
131.3 Use of Freyssinet jacks with C System anchorages
131.31 C-F type jack with hydraulic grip on strands
131.311 INSTALLATION OF FITTINGS AND JACK
a. Anchorage block and jaws (Check the correct geometrical location of the block holes, compared with the
vertical axis);
b. Pump the reusable jaw unwedging chamber (dcl) up to 50 bar;
c. Jack (check its correct inclination compared with the tendon axis).
131.312 PREPARATION FOR THE TENSIONING OPERATION
a. Pre-opening of the jack (H" 25 mm) ;
b. Pump the reusable jaw hydraulic wedging chamber (cl) up to the pressure required for the unit conside-
red (see table giving the characteristics of the jacks).
131.313 TENSIONING
a. Pumping the tensioning chamber (t) up to 100 bar;
b. Draining the wedging chamber (cl) ;
c. Pumping the tensioning chamber (t) in steps, up to final pressure.
131.314 LOCKING OF THE JAWS OF THE ANCHORAGE BLOCK
Pumping the hydraulic locking chamber (blc) up to the pressure required for the unit considered (see table
giving the characteristics of the jacks).
131.315 DRAINING AND REMOVING THE JACK
a. Establishing a slow communication between the tensioning chamber (t) and pump tank. The permanent
locking of the jaws is thus achieved by transferring the force to the tendon;
b. Partial closure of the tensioning jack (H" 25 mm) by pumping the return/locking chamber (r);
c. Pumping the jaw hydraulic unwedging chamber (dcl), whilst being careful not to exceed the maximum
pressure (see table giving the characteristics of the jacks);
d. Final closure of the tensioning piston by pumping in the return/locking chamber (r);
e. Removal of the jack.
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PPC 131/3-02.95
131. TENSIONING EQUIPMENT
C System
131.32 C -F type jack with automatic grip on strands
131.321 INSTALLATION OF FITTINGS AND JACK
a. Anchorage block and jaws (check the correct geometrical location of the block holes, compared with the verti-
cal axis);
b. Pump the return chamber (r) up to 50 bar;
c. Jack (check its correct inclination compared with the tendon axis).
131.322 PREPARATION FOR THE TENSIONING OPERATION
No operation to be carried out: the wedging of the rear anchorage block jaws is automatic, as from the open-
ing of the tensioning piston.
131.323 TENSIONING
Pumping the tensioning chamber (t), in steps, up to the final pressure.
131.324 LOCKING OF THE JAWS OF THE ANCHORAGE BLOCK
Pumping the hydraulic locking chamber (blc) up to the pressure required for the unit considered (see table
giving the characteristics of the jacks).
131.325 DRAINING AND REMOVING THE JACK
a. Establishing a slow communication between the tensioning chamber (t) and pump tank. The permanent
locking of the jaws is thus achieved by transferring the force to the tendon;
b. Closing of the tensioning jack by pumping the return/locking chamber (r) whilst being careful not to
exceed the maximum pressure (see table giving the characteristics of the jacks);
c. Removal of the jack and fittings.
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PPC 131/3-02.95
131. TENSIONING EQUIPMENT
r
Installation
of fittings
and jack
Preparation
for the tensioning
operation
t
Tensioning
blc
Locking
of the jaws
of the anchorage block
t r
Draining
and removing
the jack
C -F type jack with automatic grip
VÉRIN C -F Ä… prise automatique
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PPC 131/1-02.95
131. TENSIONING EQUIPMENT
dcl
Installation
of fittings
and jack
cl
Preparation
for the tensioning
operation
cl t
Tensioning
blc
Locking
of the jaws
of the anchorage block
dcl r
Draining
and removing
the jack
C-F type jack with hydraulic grip
VÉRIN C-F Ä… prise hydraulique
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PPC 131/3-02.95