The Rail Track was removed and the Slab demolished after the crane passed through. There is 6 Ball Mills so this process was done several times.

Adelaide Northern Expressway Center Pier Steel Cage

The steel cage was pre-fabricated on site on top of the same formwork shuttering which will be used to form-up this 6 meter tall structure.

Construction Workers To Feed The Steel Cage Into The Base

Formworkers, steelfixers, riggers and supervisors work together feeding the cage into the base making sure that every steel bar in the cage is in the correct position in relation to the starter base steel.

Steel Cage Fixed Into Position

After the steel cage is fixed into position, the structure is ready to be enclosed by formwork shuttering. The finished concrete structure will be a narrow 600mm at the bottom and 1500mm at the top.

Precasting six cone shaped concrete structures 2 at a time for the Adelaide Aqua Port Stanvac Desalination project.

Scaffolding

The 400 mm thick bases for the concrete units was poured first and the 2600 mm cone shaped section will be added on top. After the bases are poured, the scaffolding is added to enable steel fixing, formwork erection and pouring of concrete.

Tube and Fitting Scaffold

Internal Formwork

The internal formwork is 1800 mm diameter (not cone shaped) which includes 2 x 6mm plywood layers bent into shape and screwed into the vertical timbers one layer at a time.

Cone Formwork Internal

External Formwork

The external formwork below is cone shaped. It will also be skinned with 2 x 6mm plywood layers. It will take a bit longer to screw the ply to the external formwork because of all the extra cutting into the cone shape.

Cone Formwork External

Below we see the skinned external formwork being added to the structure in 2 parts. There is no way this formwork would fit around the steel in one piece, so we split it in half, lifted it in two crane lifts and joined it all up in position.

Cone Formwork

Finished Precast Concrete Unit

Below we see the finished 30 tonne pre-casted concrete unit. It will later be placed on a barge with the other 5 units and floated out to Port Stanvac Desalination Project.

Cone Shaped Pre Cast Concrete

Plain old circular formwork is a bit easier than cone shaped formwork.

Starter steel for a 7.2 meter high concrete bridge pier which will support concrete bridge spans at Healslip Road Interchange Adelaide.

Center Pier Starter Steel

Formwork will be used to box the column just as soon as the rest of the steel is lifted into position by crane. This center pier will be 13m long, 600mm wide at the bottom and 1500mm wide at the top.

While this slab formwork “may” hold the concrete, it could be done a bit more professionally by using plywood rips and a bedlog to straighten the edgeform instead of wire. I can’t believe the formworkers that did this job recon it was ready for concrete.

Dodgy Formwork

Using wire back to a single pin to pull the formwork into line is dodgy and time-consuming because the pin can flex (or the wire can break) and put a “dog leg” in the formwork.

Dodgy Formwork Braced without a Bedlog

Tip: If it is important to have nice straight formwork (it should be), always use a bedlog. A bedlog enables you to push and pull the formwork into the exact position, secure it properly and “walk away”.

Even if it is not important to have nice straight formwork because the crooked concrete will “never be seen”, it is not a good look to have dog-legs in a concrete slab. By the way – It will be seen before it is never seen. It will be seen by bosses and inspectors.

This is the formwork which will be used to cast the bridge bearings into position on top of the concrete columns. Silicon sealer was used to completely seal the formwork in order to stop any grout leakage, while at the same time holding the formwork securely in position.

Bridge Bearing Grout Formwork

You’ll notice that the original holes that were voided out during the concrete pour have been filled in with grout and new holes have been core-drilled. Why? ..

This happened because either the wrong hole centers were supplied to the formworkers, or a different size Bearing Pad was supplied in the end. Every column top had to be core-drilled in this way

You’ll also notice that the surface has been scabbled. This is specified as part of the job to ensure that the grout bonds properly to the concrete.

Tip: Don’t try and get away without scabbling the concrete if instructions were not given to do this job. Treat it as part of the job and do it without being told.

Here’s Joe surveying the exact locations of the bridge bearings which will be cast on top of the concrete bridge columns at Port River Expressway roadworks project.

Joe at Port River Expressway

Because the bridge spans will be sitting temporarily on timber packers, Joe also had to calculate the correct height of each packer for each corner of every column.

Not only that, each corner of each timber packer will be a different height because of the North/South and East/West bridge span angles.

Promise not to leave you up there when we go to lunch Joe

Tugan Bypass Boys Mark and Terrence take shelter under a bridge on a rainy morning. Mark and Terrence have been doing the concrete and formwork at this crash barrier foundation.

Mark and Terrence at Tugun Bypass Project

A nice collection of Prominent Hill photos by Zane Swart. This collection contains 506 photos of around the Prominent Hill Mine job, and other fun after work hours stuff. Start Slideshow

Zane and Yabbie at Prominent Hill

View Zane’s Prominent Hill photo collection.

Shane Chooking Yabbies

Thanks for that Zane

After each column concrete pour, the column formwork gets stripped down to be cleaned with high pressure water blasting and grinding with a wire wheel to remove all the slurry.

Cleaning Column Formwork

After cleaning, a special oil is applied to the forms which ensures they will strip off easy next time, and also helps provide a nice smooth finish on the concrete.