Formwork Blog

Archive for the ‘Glossary’ Category

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.

Structural Bearings – Bridge Bearings – Also known as bearer pads or bearing pads.

Structural Bearing – Bridge Bearing

Bridge Bearings go inbetween the structure and the bridge span. For example, Bearing Pads can be fixed onto abutments, bridge columns and/or headstocks then bridge spans are fixed onto them.

Iron Duke Mining Construction Site South Australia

Avoid injuries by using a star picket driver to drive in star pickets when erecting safety barricades. Avoid back injuries by using the star picket extractor (also called star picket puller) to extract those star pickets from hard ground.

Star Picket Extractor and Driver

The ground was so hard at Iron Duke mining construction site that many of these star pickets bent over at the “bite point” before they would budge. Here is a star picket being extracted from hard rocky ground with the star picket extracting tool.

Star Picket Extractor in Action

Tip: That part of the star picket extractor that “bites” onto the star picket can be extended with a short chain which makes it much easier to use.

Star picket drivers and extractors can be hired from most good plant hire companies. They can also be purchased at all good stores which sell rural fencing supplies, and other good outlets which specialize in roadworks equipment.

I have been doing a bit of looking around Online at certain rural outlets for these items and have found that many Rural Supply outlets along with Plant Hire companies say on their web site “no photo available”. Hell, if they actually have the item for sale or hire, then there *is* a photo available, all they have to do is take a picture and upload it to their web site.

Tip: If there is no photo available, I think they are not a “good” store. You need to actually see what you buy or hire Online, else you’ll have to settle for what they send (which could fall short of your expectations).

A ride-on concrete troweling machine is used to finish concrete slabs in a similar way as a regular concrete trowing machine but is handy for finishing much larger areas.

Ride-On Concrete Troweling Machine

At last, concretors can sit on their arse and finish concrete at the same time

An Invisible Beam Laser Level is used to determine an elevation from a known Datum Point. An Invisible Beam Laser Level is a handy tool used often by formworkers and concretors to set concrete heights, formwork heights and excavation depths.

Invisible Beam Laser Level, Tripod, Grade Pole, Receiver, and Grade Pole Level

Tip: Always calculate an elevation from an official Datum Point or RL (Reduced Level), not from some part of a building or structure which is “supposed” to be at a particular elevation.