HOW THE RIGHT EQUIPMENT CAN MAKE THE TILT-UP PROCESS SAFER AND EASIER
Improving tilt-up panel construction with Hilti's new HBI anchor
There are a few key traits that every successful construction project shares. From stability and precision through to a speedy building process, these qualities are what make a jobsite both safe and productive, with tilt-up construction boasting all of these benefits and many more.
While the method is becoming increasingly common in the Australian construction industry, it's important to recognise the importance of best practice and proper equipment - especially when it comes to the anchors used for fastening concrete slabs. In this article, we'll take a closer look at the basics of tilt-up construction, and the right tools for the job.
An introduction to tilt-up construction
In a nutshell, tilt-up construction involves prefabricating large concrete panels, which are then lifted into place and fastened to a slab. The first step in the process is slab preparation, where the large concrete segments are cast. This typically happens in one of two ways; the panels can be cast directly on-site to minimise transport costs or they can be prepared off-site and then transported by truck. While on-site casting is very convenient, transporting the panels is more common in bigger cities where space is at a premium.
Once the panels are in position, they are lifted up and held in position by special supports known as 'props' or 'braces'. One end of a prop attaches to a cast-in ferrule on the vertical concrete panel, while the other end is directly fastened into the slab itself. Once each panel has been erected and fastened together, the building will be stable and ready for completion. Hilti Trade Manager Martin Stirling puts it very simply:
"It's a really quick way of getting a lot of square metres up in a short space of time. Before you know it, you've got several panels in place, and there's a building where a few minutes earlier there was nothing," he said.
The benefits and challenges of tilt-up construction
Here in Australia, tilt-up construction was traditionally used for low-rise industrial estates in areas with lots of flat land, where the process could be completed incredibly quickly. Over time though, the benefits of tilt-up has seen the method move to the cities, and now there are more and more high-rise building projects, such as apartments, being undertaken with the technique. This is especially the case in cities such as Perth, Adelaide and Melbourne, where the landscape is flat and there's the right infrastructure to transport the large concrete panels to jobsites.
In many ways it's a similar technique to permanent formwork applications, and these two processes are taking the nation by storm thanks to their speed.
"These technologies are becoming incredibly popular as labour becomes more expensive and developers are put under greater pressure to get projects finished in shorter amounts of time," says Martin.
All of this being said, there are still several challenges associated with tilt-up construction. The first one of these that Martin points out is design tolerances, where each panel needs to be made accurately so that, when bolted together, every part lines up perfectly. Another big concern is safety, and although relatively rare, there have been a few instances over the years where panels have collapsed - highlighting the importance of proper installation.
The right anchors for tilt-up panels
As you'd expect, one of the most critical components of the tilt-up construction process is the brace that holds each section in place. First of all, each prop needs to be well-attached on the vertical plane, requiring the cast-in ferrule to be perfectly designed and installed properly. The same goes for connection to the slab on the horizontal plane - an anchor that is always post-installed. These anchors have their own regulatory code, ensuring that each building erected using the tilt-up technique is as strong and stable as possible.
To this end, Hilti is introducing a brand new anchor designed specifically for the connecting panels and props on the horizontal plane - the Hilti HBI panel brace anchor. This expansion anchor is a specially designed and tested in accordance with the tilt-up regulations (AS 3850.1:2015), and boasts a special compression ring that generates a fixture clamping effect. It's an exciting product, and one that will make this innovative and critical construction process faster and easier than ever before.