Wednesday, May 30, 2007

The process of propping up our tilt up slabs once lifted into place is to attatch props to cast in fixing rebates etc on the slabs end, and to fix it to a footing poured about 1/2 the distance of the height of the wall away from the wall itself. The propping is connected about 2/3 of the way up the wall, or at about 60 degrees from the angle of elevation. These of course, are only temporary until further lateral support is introduced (eg. flooring, roofing, next storey formwork, structural steel or other structural components.)

A joint detail for the pouring of two seperate slabs, with construction control joints installed. The dowell by theory is free to move as temperature changes, but in this case, after curing, the slab cracked, and they beleive that not enough clearance was left. The detail shows 25-30mm is needed.

We can see here a typical portal framing section with the structural elements and the wall and roof cladding. Notice the size of the beams and the decision not to use a haunching in the knee joint...

this detail here we have a universal beam column, supporting the roofing rafters and perlins. You can see the method of fixing here, with the cleat plates and two m20 bolts holding up the rafter, and the rafter is connected to the perlins in the same way.

This is your typical cast in plate fixing detail. These plates are used to tie the panels together once erected and are connected with m20 bolts. These plates, as you can see, are cast into the panel and have a significant amount of reinforcement to support them.

A simple detail depicting the connection or fixing or a typical tilt up slab to a strip footing. The Panels have a cavity that is cast in during the curing process, and allow for the panels to be easily located onto the placement bars that are cast into the footings. These placement bars are generally 600-700mm long and are spaced about every 500-800mm for larger slabs, or can be placed at either end of panel.

This detail shows us the placement of the wall slab and the floor slab and the reinforcement needed. You can see that the floor slab extends to 600 below the NGL, and tilt up slab itself to 250 below the NGL, there are no footings as normal, as these walls are non, load bearing, and are tied to each other and act as footings for their own weights and disperse loads throughout the foundation.

See below

This is a detail same as below, but for the external load bearing walls of the project.

This detail shows us the footing detail for a tilt up panel project, specifically for a project in laverton, a large warehouse, and the reinforcement placing in the slab and the fixing of the slab to the footing for internal walls.

this detail shows the footing detail of a precast tilt up slab and what the specifications are. Generally, all multi storey or large tilt up slab units are placed onto a strip footing, which is also supported additionally by a pier or pile beam footing to take the excessive loads and distribute them deeper through the foundation. although a strip footing is perfectly capable of taking care of a tilt up slab project, if the engineer deems it applicable.

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