C:\Users\David Moloney\Desktop\Road Bridge 182 Infographic

Bridge Deck Construction - Insitu with void formers & post-tensioned

David Moloney 22th Dec 2010

Step 1 - Falsework, Soffit Formwork & Bearings Step 2 - Fix Reinforcement Step 3 - Fix Ducts for stressing Step 4 - Fix Stop ends & Anchor Coens

Spiroflex 85 mm dia tubing & vent pipes

Vent Pipe Duct Profile curved

Anchor Anchor

Abutment Abutment Pier Abutment .

Pier Longitudinal Deck Section Duct

Walkway & Working Platform Grout Tube

Abutment Block

Wedges Coen

Strands

Anchorage for Strand Tendon .

Sequence for Walls Pours Abutments davmol

C2 Bottom Adapt shutters Adapt shutters Alternatively done after Concreting

A2 Bottom C4 Bottom C6 Bottom Step 5 - Push in Stressing Strand Step 6 - Fix void Formers Step 7 - Pour Deck Step 8 - Pour Parapet Upstands

C2 Top A4 Bottom A6 Bottom Strand Dispenser & Pusher Material - Expanded polystyrene formers & metal fixings Concrete pumps 32 m boom x 2 nr

A2 Top C4 Top C6 Top Strand 15.2 mm dia high tensile Used to reduce the deadweight of the structure. 420 m3 of concrete or 61 loads, pump 8 loads per hour

A4 Top A6 Top Speed 40 to 60 m per minute

Typically 20 nr. strands per Tendon

Bridge 182 - Deck Pour Methodology

Materials

C 50 Slump 125 +/- 25

Concrete Volume 1,200 cu. M.

Approx 50m long x 24m wide x 1 m deep Step 9 - Stress deck & Erect Railing Step 10 - Strike Falsework & Formwork Step 11 - Grout Tendons Step 12 - Waterproof Deck

Plant Paths & Rubbing StripsBatching Plants on Site. Located @ NDA Per Hour Asphalt to carriageway

2# Liebherr Betomix 2.25 outputs 60 cu m per hour each 100 cu m Jack 350 tonne multi stand & Hydraulic Pump. Grouting provides:- Grout Mixer & Pump

1# Turkish plant outputs 60 cu m per hour each 50 cu m Strand extensions are measured during loading. 1. Corrosion protection to the strands.

Concrete Pumps 2. A bond between the strands and the surrounding concrete.

Positioned on either side of deck, will be moved once during pour. Span centres lift during stressing.

42m Boom capacity 50 cu m per hour

42m Boom capacity 50 cu m per hour 100 cu m.

Duration; 12 hours

Lorries Capacity 8 cu m per load

Cycle time Load travel discharge & return to bataching plant = 60 minutes

100 cu m per hour divided by Lorry 8 cm per hour = 13 lorries

Vibrating Equipment 6 # 50mm dimeter Electrical internal poker vibrators

Concrete Finishing Equipment Levelled by Shovels & rakes Aluminium Screed by Hand

Curing Equipment By liquid membrane using mechanical sprayer

Deck Construction SequenceStep 1 Erect Falsework Hot Weather Concrete

Step 2Erect Soffit FormworkStep 3Fix Bridge bearings Specification requirements

Step 4Erect Formwork for Cantilever Ribs Max Placement Temperature 32*C

Step 5Fix Bottom matt of reinforcement & cages Max Core Temperature 65*C

Step 6Fix ducts for tensioning Maximum differential temperature 20*C

Step 7Fix stop ends and anchors for tensioning

Step 8Fix void formers Actions to ensure above

Step 9Pour deck & contilever ribs Flaked ice is used in mix to control temperature

Step 10Push in stressing strand Pour in evening in hot weather

Step 11Stress deck Proper Curing

Step 12Grout tendons

Step 13Pour parapet wallsStep 14Pour curved Masking FasciaStep 15Strike Falsework

Deck Pour 1,400 m3 5am to 9pm 4# pumps Step 16 Other Works Trial Deck SectionJoints, Paths, Rubbing Strips, Surfacing, Railing, Painting

Pumps Capacity 42m boom 60m3 per hour 35m boom 40m3 per hour

Falsework is the temporary scaffold system used to support the

formwork to the deck soffit.

Formwork aka shuttering is the casing used to contain

concrete during placement and hardening

Note: the tendon profile lies in the bottom of the deck in the

mid-span region and rises to the top of the deck over the

supports. When the tendons are stressed the deck is

compressed in those regions where the load causes tensile

stress. Precompressing the tensile zones of the deck reduces

cracking to produce more durable concrete deck.