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.

Instead of the regular workplace BBQ lunch on a Saturday, why not try out a workplace Lamb On A Spit like we did here at this construction site in Port Adelaide. The site is being used by Adelaide Aqua to prefabricate pre-cast concrete and large steel piles for the Port Stanvac Desalination Project.

We had seasoned Lamb-On-A-Spit Professional Branko on the team who prepared, cooked and carved the lamb to perfection.

Branko’s delicious roasting lamb smell wafted over the whole construction site, enticing most of the construction workers over to have a great tasting lunch before hooking back into work. After most of the site ate, there was plenty left over for hot lamb sandwiches the next day.

I voted 10 out of 10 for Branko’s Lamb On A Spit as did everyone else who tried it.

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

After constructing this bridge abutment formwork at the Port River Expressway, formwork carpenters Steve, Simon and Tony now have to place and finish the concrete as well.

Formworkers Steve, Simon and Tony

Steel bridge spans will now placed from these abutments to the concrete columns.

Normally, when the red light is flashing and the safety boom is down at a railway crossing, the intention is that drivers wait until the train passes, the safety boom raises and the lights stop flashing. However, some people are in a bit of a hurry and take the chance.

Truck Crossing Track whille Boom is Down

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.

Here is the concrete bridge columns resulting from the use of this column formwork. The bridge will eventually span accross one railway track and one busy main road.

Concrete Bridge Columns

Formworkers are now almost ready to cast in the bridge bearings on top of these columns which will support the steel bridge spans. But first, surveyors must mark out the exact location of the bridge bearings.

Alternative View of Concrete Bridge Columns

Instead of scaffolding, elevated work platforms (EWP’s) will be used to gain access to the column tops. For safety, tube and coupler guard rails will be errected on top of each column before any other work begins.

Yet another unsafe looking truck I saw while doing Bridge Formwork at Port Adelaide. It should be noted that this is not some quiet back street, but a very busy main road.

Dodgy Unsafe Looking Truck Load

Formwork carpenter Ray goes inside these bridge column concrete forms to ensure that the reinforcement steel has the correct cover by positioning small concrete blocks (aspros) in between the formwork and the reinforcement steel.

Formworker Ray at the Port River Expressway Job

Example of no cover on a Gold Coast high-rise apartment building.

All the access scaffolding is now complete on this bridge column formwork. We are not quite ready for concrete yet because city council inspectors must give the okay first.

Column Formwork Almost Ready for Concrete

City Council inspectors will climb up the access scaffolding and make sure that the column forms and reinforcement steel inside the concrete forms are positioned according to the specifications on the plan. In most cases, the inspector will give it the go-ahead.

In my experience, the only times an inspector does not approve a concrete pour is when some formworker did not do what they knew had to be done. These formworkers hope that the inspector does not see that bit of steel too close to the concrete form, or that bar-chair that fell down to the bottom.

Or worse, sometimes a supervisor will instruct a formworker “not to worry about it”, then after the inspector picks it, they rush around like a freaking idiot trying to get it fixed

See the arial view of this formwork.