25/08/2020
What time is it?
it's 4am, sorry to wake you.
Why are you up so early?
I’m meeting Gary to watch a concrete pour of a warehouse floor in Kelmscott.
Ok… Have a good day, I’m going back to sleep.
If you work in concrete, this is one of life’s little realities, the hours are not social.
Gary and I meet at a 24hrs McDonald's, it’s 5am and it’s dark and cold. The reason for the meeting place becomes clear when he asks me if I want a coffee. He orders 12 and the same in cheese-burgers, no he’s not on an anti-diet, it’s for the crew we are about to visit. Gaz is one of those good blokes you run across in this game, someone who appreciates work done well and understands something as small as a coffee is the simple currency of thanks on a worksite.
We arrive at the construction site and it is a hive of activity. The roar of diesel generators powering lighting booms, placing machinery and trucks revving as they blend concrete in 5m3 bowls before being checked and placed. Donning the appropriate PPE we walk over to meet Dominic, the foreman, who is busy directing trucks to the pour point while the laser screed moves into position. He is obviously busy but takes a moment to grab a coffee and have a quick chat. He has been on site since the time I awoke that morning and almost ¾ of the bay is already poured as we arrive. He spots a couple of the team resting on rakes and immediately sets them to work, getting ready for the next section of the pour. Time is money and there is no time for slacking on this worksite.
I wonder what they think about a concrete technologist turning up on site but once it is explained Gaz is showing me a few sites using the Dramix fibre system the conversation quickly turns from how good the concrete from BGC is, compared to other suppliers, to whether the Eagles will be in the Grand Final this season.
If you have never seen one, click https://www.youtube.com/watch?v=8kb2YsQAsh8to see a laser screed leveling concrete. It’s quick and accurate, the days off back breaking hand screeding on commercial floors are now but a distant memory. The limit to how much concrete can be poured in a day is now not defined by physical ability but rather managed to ensure appropriate sized pours to minimize shrinkage impacts and placement requirements for equipment yet to be installed.
If you did watch the video you would have noted two obvious things, the wooden boxing and no reinforcing mesh. The job we visited was using a fantastic alternative edge strengthening system to replace the wooden boxing using a metal AlphaJoint from The Construction Store– this form of boxing remains in the slab after placement and is specially designed to prevent slab edge damage when driven over. The limit to slab dimension with the Dramix fibres is really determined by practical considerations on allowable joint width with anything from 30 to 50 metres square, without an internal sawcut, being common. The system is impressive, so the next time you are in a newer Bunnings warehouse, look down and marvel at how far concrete floors have come in the past 20 years.
Followup: I asked a few builder friends why the dramix fibre system and laser screeds had not found their way into house construction. The standard answer was cost and customers haven’t asked for it. When you see the quality that can be achieved on an industrial warehouse floor you have to ask is it really a case of an uninformed public not knowing what is possible for the foundation layer of their most expensive possession?
How many sins of the slab are covered by screeds and carpet when truly flat floors are achievable?
How many bad concrete practices in the area of added water could be removed if a laser screed meant the back breaking act of hand-screeding was eliminated?
www.lascrucesconstruction.net
