SECOND PENANG BRIDGE

8/12/2019 SECOND PENANG BRIDGE

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Concrete

Pre-tension

Post-tension

Presented by:


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What is Prestressed Concreted?

A pre-stressed concrete structure is different from

a conventional reinforced concrete structure due

to the application of an initial load on the

structure prior to its use.

Steel reinforcement introduce in combination

with concrete as reinforce concrete were ideal to

become a very strong and cheap buildingconstrual members


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PRESTRESSED CONCRETE

PRINCIPLE

Using high tensile strength steel alloys producing

permanent pre-compression in areas subjected to

Tension A portion of tensile stress is counteracted thereby

reducing the cross-sectional area of the steel

reinforcement


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The factors in chosen Prestressed

Concreted

RAPID

CONSTRUCTION

LONG SPAN

MAINTANANCE

FEE & SERVICES

SPACE

TO CONSERVE

HEAVY LOAD

VERSATILITY

DESIGN

FIRE RESISTANT


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TWO METHODS OF PRESTRESSED

CONCRETE

PRE-TENSIONED

HARPING/STRINGING

POST TENSIONED

BONDED POST-TENSION CONCRETE

UNBONDED POST-TENSION CONCRETE


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PRE-TENSIONING

The tendons of the reinforcement are stressed

and anchored at the mould before the concrete

is poured

Tendon are release from the abutment and the

pre stress is transferred into the concrete

member.


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PRE-TENSIONING

Pre-tension drawing detail.


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POST TENSIONING

It is one in which the reinfor cement is tens ioned after

the conc rete has fu l ly hardened.

A post-tensioning tendon is made up of one or more

pieces of pre-stressing steel, coated with aprotective coating, and housed inside of a duct or

sheathing. A tendon will have anchors on each end

to transmit the forces into the structure.

Long tendons may also have intermediate anchors

along their length. The pre-stressing steel can be a

high strength steel strand (typical in horizontal

applications) or a high strength steel bar (typical in

vertical applications).


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Typical post tensioning system

POST TENSIONING


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POST TENSIONING

Materials &

Components

Steel Wire Strand

Standard Couplers

Anchor Head And Wedges


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Steel Mould Ducting

POST TENSIONING

Material & Component


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POST TENSIONING

Machines

HYDRAULIC

STRESSING PUMP

GROUTING

MACHINE

MOBILE CRANE

HYDRAULIC JACK


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POST-TENSIONING

BONDED & UNBONDED

BONDED UNBONDED

The concrete is castaround a plastic, steel or

aluminium curved duct, to

follow the area where

otherwise tension would

occur in the concrete

element.

Each individual tendons iscoated with a grease

(generally lithium based)

and covered by a plastic

sheating formed in an

extrusion process.

USUAL PROBLEM AND


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USUAL PROBLEM AND

FAILURE

PRESTRESSED CONCRETEPRESTRESSING COMPONENT

Wire, strands and Tendons Failure

Tendons Extension Grouting and Ducts

Corrosion

CONCRETE AND REINFORCEMENT

Concrete Cracking

Concrete Spalling

Honeycombing

Concrete Cover

USUAL PROBLEM AND


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USUAL PROBLEM AND

FAILURE

PRESTRESSED CONCRETEPROBLEMS DURING CONSTRUCTION

Failures Due To Design

Construction Procedures Structural Behavior Problem

PROBLEMS AFTER OPENING

Durability

Rehabilitation and Meditation


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SITE LAYOUT


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PROJECTDETAIL


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BRIDGE.

PRESTRESSED

CONCRETEPost tension Segmental Box Girders The precast segmental box girder is designed as a continuous

single twin box of 14.08m width,4.0m length and 3.20m depth

structure with match cast joints, multiple shear keys and

prestressing tendons.

This type of box-girder was selected because of its size that

does not require extensive casting facilities, special heavy lifting

equipment and storage as compared to a precast full-length box

girder.

Total 7 types of Segmental Box Girder are designed for each

span.

Total 8,092 nosof segmental box girder are constructed along

the bridge.


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Typical Cross section of

SBG

16m is enough for th ree lane highway.

4.0m length and 3.20m depth s truc ture with

match cast jo ints, mul t ip le shear keys and

prestressing tendons.

Width 10-16m Width 10-16m


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CASTING

SEQUENCE

Tying rebar and ducting to in

dedicated reinforcement jig

Placement of reinforcement

cage in the SBG mould

Final inspection beforeconcreting


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Concreting the SBG

CASTING SEQUENCE contd

Completed SBG transported to

yard

SBG storage yard


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Span by Span

Method


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Installation of duct and anchor

head


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Stressing SBG process has beendone on site.

Setting the

Hydraulic Jack

with good position

to SBG tendons.

Hydraulic Jack

Lifting Cable


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Stressing SBG process has beensupervised by Engineer.

Tendon stress is

controlled by

Hydraulic Pump.

Hydraulic Pump

Hydraulic Jack

Fi ll G ti th SBG


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Finally, Grouting the SBGGrouting Machines & High pressure of pump

are used to grouting the SBG completely.


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Application of Epoxy as the Glue

for the connection of SBG


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SUPERSTRUCTURE PENANG BRIDGE.

POST TENSION BEAM AND SLAB D

The cable stayed bridge utilizes post

tensioned concrete beam-and-slab

decks.

Typical beam height:

2.8m

Deck slab thickness:

28cm

Post tension slab deck at stayed


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Post tension slab deck at stayed

cable Penang Bridge II


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structure

Prestessing in

progress.

Marked the strand before

stressing

Install the anchor

Post tension Beam structure


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Post tension Beam structurePrestessing in

progress.

Setting the Hydraulic Jack Install the wedges

Prepare to be stressed


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structure

Prestessing in

progress.

Set up the Hydraulic Pump

Record the result of stressing


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Pre-stressed Beam launchingprogress

Pre-stressed beams and deck slabs have also been

launched for the superstructure of bridge at the Mainland(Batu Kawan & Batu Maung)


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The launching of Pre-stressed

Beam


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References

(Enc ik Am inudin Al i , Prestressed Concrete: 2013)

(Matt Carter, 2nd Internat ional Seminar on Design &

Constru ct ion of Second Penang B ridge: 2008)

(Dato Prof Ir Dr. Ism ai l , Sust ainable Br idge Asia

Constru ct io n Pract ices, 2009)

(Dr. Bi jan O. Aalam i, Unbo nded and b ond ed Post-

Tensio ning System :1994)

(Mod jeski & Master, Inc , Prestressed Concrete Girder

Superst ructu re B ridge Design :2003)


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Documents

SECOND PENANG BRIDGE