Formwork Blog

When I arrived at Construction Camp 123 Cape Preston Western Australia, I was wandering who would be the first person I would bump into that I already know from another job. Well, it was formwork carpenter Rami who I first met at Prominent Hill SA a couple of years ago.

Ed and Rami at Cape Preston WA

Good to see ya mate

Location: Port Adelaide SA

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.

Location: Port Adelaide SA

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.

Lamb On A Spit

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

Branko, Graham and Goran

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.

Daniel, Dave and Branko Carving The Lamb

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

Northern Expressway Adelaide SA

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.

The photo below shows a formworker using a dodgy welding unit which was supplied by a plant hire company in Adelaide. What is wrong with this picture?

Dodgy Welding Unit

It is dodgy because the handpiece cable is only 1500 mm long! Therefore, the formworker must position this stinking, petrol-powered welder right next to himself so he can breathe in exaust fumes all day long.

When this issue was raised with management, the exact reply was: “That’s all they had”. That excuse does not make this safety issue go away! Send it back and tell the plant hire company not to send out unsafe, sub-standard equipment.

When requesting plant from a plant hire company such as this petrol powered welder, you should show that you know what you are talking about by telling them to supply long handpiece cables instead of just getting what CRAP they send you.

Why pay full price for sub-standard plant?

Don’t Be A Bozo

Don’t be a bozo and breathe in petrol exaust just because management cannot organize safe plant and equipment. You are better off getting fired than breathing in that shit for a day, a week or even months.

A common excuse construction supervisors give is “that’s all they had” or “that’s all we’ve got”. That’s is not your problem! Don’t be a bozo and use dodgy, unsafe plant and equipment.

Location: Northern Expressway Adelaide SA

When Z-Bars become difficult to extract because concrete slurry has leaked into the conduit, it may be necessary to make a heavy duty Z-Bar extracting tool.

Z-Bar Extractor

Simply cut a notch in the plate of a Prop-Inner, Screw-Jack or similar item. The notch should be slightly bigger than the diameter of the Z-Bars being extracted.

The length of the Prop Inner tube should be cut down to a manageable length while keeping in mind that the longer the tube (handle) is, the more effective it will be for extracting stubborn Z-Bars. (The longer the handle, the heavier the tool.)

Z-Bar Extractor In Action

To use the Z-Bar Extracting tool, remove the Z-Bar plate (washer) and replace only the nut. Then simply slide it along the Z-Bar towards yourself smashing the nut.

The photo above shows us using the Z-Bar Extractor to pull out a stubborn 4 meter long, 25 mm thick Z-Bar from a poured concrete pier. The Z-Bar Extracting tool made light work from what would otherwise have been one of those crappy never-ending jobs.

Pitfalls To Avoid

Important! Don’t be a bozo and smash your fingers into something while pulling back with the Z-Bar Extracting tool! Look around before you start smashing.

Tip: The length of the handle should be determined by your surroundings. For example, you would not have a 2400mm handle if you were working from a tight scaffold. You would cut it down to say 900mm – 1500mm max.

Tip: Using the Z-Bar Extracting tool on Z-Bars that are not so stubborn is also a good idea because it will reduce the number of times the ends need to be ground-down in order for the nut to fit properly.

Smashing Z-Bars out the regular way with a hammer will burr the ends, increase servicing requirements and produce down-time when someone goes to screw a nut onto a burred Z-Bar.

Location: Bolivar Water Treatment Plant SA

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.

Location: Whyalla Pellet Plant South Australia

Here’s another thrust block formwork job we had to do, but this time it was below the water table which means that water would be continually pouring into the job the whole time.

Thrust Block Excavation

Imagine arriving at this job and they say they want a couple of thrust blocks around these pipes, and they want it quick coz it’s “just a couple of thrust blocks”

Pumping the Water Out

Not only that, Des had to be very careful while digging out this watery goop to avoid damage to the fiber optic telecomminications and electrical cables while the pump pumps water out all day long. Des named this job The Swamp Monster

Concrete Thrust Blocks (Pump Still Pumping)

Finally the job is done and the Concrete Thrust Blocks are in position. The formwork for this job was almost the same as this other thrust block formwork we did.

Location: Prominent Hill Mining Construction Site South Australia

Mechanical Fitter Leigh (Hollywood) giving Admin LJ a few welding tips.

Leigh and LJ at Prominent Hill Mine

Location: Port Adelaide South Australia

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.