Transcript
1
PRESTRESSING
OF THE BRIDGES
2
PRESTRESSING SYSTEM INTERNAL TENDONS
(led inside the concrete structure) top straight tendons bottom straight tendons curved tendons inside webs horizontal straight tendons inside webs
EXTERNAL TENDONS (led outside the concrete structure)
running free inside the boxgirder
3
Types of the tendons
4
INTERNAL TENDONS
15 pc strand / tendon Dstrand = 0,6” (15,2 mm ) Astrand = 150 mm2
Type ST 1670/1860 N/mm2
Finit = 2973 kN / tendon Dout = 95 mm corrugated sheathing Anchorage system :
DYWIDAG SI (DSI) MA 6815 (Multiplane anchorage)
pressure grouting with cement grout
5
INTERNAL TENDONS AND ANCHORAGE SYSTEM
Dywidag SI MA 6815 anchorage systemCorrugated sheathing
Corrugated sheathing
Plastic trumpet
Ribbed anchor body
Wedge plate
Groutcap
6
INSERTION OF THE STRANDS
INTO DUCTS
Strandpushing device
Strand in
Insertion into the web
t
Insertion into the bottom slab
Strand out
8 m/s
7
PRESTRESSING OF THE INTERNAL TENDONS
Wedge plates
Wedge plates
Inserted tendons prepared
for prestressing
Hydraulic jack for prestressingHoZ 4000 ( kN )
stroke=250 ( mm )
8
EXTERNAL TENDONS
VORSPANN TECHNIK TENDONS ( double-extruded )
4 X VT-CMM 04-150 D band / tendon (16 pc.strand / tendon )
Dstrand = 0,6” (15,2 mm ) Astrand = 150 mm2
Type ST 1570/1770 N/mm2
Finit = 2973 kN / tendon Anchorage system :
VORSPANN TECHNIK VT CMM 16X150 anchor block
9
EXTERNAL TENDONS
VT-CMM BAND
VT-CMM 04-150 D
VT-CMM 02-150 D
10
DEVIATORS OF THE EXTERNAL TENDONS
Top deviator Top deviator
Bottomdeviator
External tendon
Bottomdeviator
LONGITUDINAL SECTION
11
INSERTION OF THE EXTERNAL TENDONS
Reels of bands
Pulling of the tendon
into the
boxgirder
Tendons inside the boxgirder
on temporary flying support
12
DEVIATORSTendons across
the deviatorTrumpet seal for
VT-CMM 4x04-150D
tendons
at the anchorage
VT-CMM 4x04-150D
tendon
Spare hole for tendon
13
PRESTRESSING OF THE
EXTERNAL TENDONS
ANCHOR BLOCK
Tensioning by means of VT 4000 ( kN )
prestressing jackstroke= 200 ( mm )
14
SAMPLES FOR THE APPLICATION OF EXTERNAL TENDONS
Anchorages inside a boxgirder
at a stiffener - tendons for launching
Tendons at top deviator
top related