Formwork Blog

Posts Tagged ‘Bracing’

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: Prominent Hill Mining Construction Site South Australia – Weigh Bridge Section

Timber used to brace internal sump formwork at Prominent Hill weigh bridge.

Weigh Bridge Sump Formwork

You’ll notice that one of the center timbers is not used to brace the concrete forms, rather, it is used to support the yellow ladder treads. Extra z-bars and timbers that support the external forms are also just visible in the above photo.

Sump Formwork Ladder Support

The vertical timber holds the ladder treads firmly against the plywood while the treads are wired to a nail (not visible) keeping the treads horizontal.

Sump Formwork Ladder (internal view)

You’ll also notice that there is two pieces of ply used in the center of the ladder tread instead of one which makes easy work when it comes to stripping. On the other hand, if one piece of ply is used for these types of formwork, it is a time-consuming nightmare to strip.

Location: Prominent Hill Mining Construction Site South Australia – Weighbridge Section

I bumped into a construction worker friend of mine recently at Whyalla shopping center who said he just had some formwork blow-out during a concrete pour. I asked him if he used a Bedlog to brace-off the concrete forms, and it turns out he did not.

Whenever you suspect that the pressure on your concrete forms will be more than your average driveway slab, or you are having difficulty maintaining a straight line, it could be a good idea to consider placing a Bedlog down in order to have something solid to brace your formwork off.

Formwork Carpenter Laying Down a Bedlog

A Bedlog (also known as a Dead-Man) is used to secure both walls and slabs and can be used on even and un-even ground. Use the Bedlog to push and pull your concrete forms into a perfectly straight line and hold it securely in position.

Concrete Wall Forms Braced With Bedlog

In the photo above, only the top of the concrete forms is braced onto the bedlog because the bottom of the forms is inside an excavation. If the entire job was on level ground, the bottom of the forms would also be braced back to the bedlog.

Bedlog Secured With Pins And Wire

Bedlog vs Pins Only

A Bedlog enables you to push/pull and secure the concrete forms into a nice straight line while bracing with pins/pegs only allows you to push. This allows you to totally eliminate any dog-legs while eliminating all movement from the formwork.

Using only pins/pegs can fail and cause the concrete forms to blow-out while a Bedlog is much stronger and therefore more reliable.

Using a Bedlog enables you to erect your formwork and walk away. What this means is that in most cases you will not have to be nearby “watching the concrete pour” because you are worried that your formwork will collapse under pressure.