Dumb question but I've looked online and it lists some steel companies that will do rebar but I suspect for a small DIY project they'll not be interested. So where do you get rebar? people like wickes don't seem to stock it..
Like anything ebay or amazon. Although cheaper if you can find someone near on ebay so you can collect.
As above, builders merchants. Or if you have a local steel stockholders, try those. A local reinforcement company might well be open to a little cash deal too.
Builders merchants are miles better for anything, I often wonder how places like Wickes stay in business. They're bloody expensive and the quality is hit and miss at best.
Because most builder's merchants don't advertise to the public and therefore many people don't know where they are or much about them. They are great for DIY stuff most of the time. B&Q etc couldn't get me the right length planks for fencing I needed. Popped to the local builders merchant and they cut planks to the right size for half the price of the ones B&Q were flogging.
Thanks A local place is happy to sell me a couple of lengths of 10mm x 6 meter and cut them down to fit in the back of the focus (so 6 lengths of 2m). £5 for each of the 6m! I'm building a telescope pier. the base is 61x61x80cm then the pier is a octagon 25cm diameter about about 90-120cm tall. In all about 735Kg in total. Rebar is used to prevent the movement of heavy scopes etc from putting stress on the concrete during faster rotation (rather than downward force). As the mount is tracking stars at an accuracy of three 10p coins a 1 Km away.. the rebar adds more stability. The pier wil also double up as a table and parasol holder for summer. The rebar will be tied to the central 1.5" pipe to hold the parasol. Then a couple of 1m lengths of M12 threaded rods will then hold the mount on the top - these hold a couple of brake disks (because they're flat and make a good base for the mount). I've been cutting the concrete former out of 11mm OSB2 board for the octagon at the weekend (23deg angle of circular saw makes it fun). It will be exterior varnished to prevent the moisture of the concrete from soaking in whilst it sets. I still have a few bags of aggregate to get and some concrete (I have about twenty 25Kg bags already of aggregates).. hire a mixer for a couple of days (the pour will be one day and continuous).. bish-bash-bosh.. then a month later seal the concrete and jobs a gooden.
This is the former.. I've finally got the first ring to fit. I still need to re-cut the base ring (it will have two rings and a base ring. The former will hold the concrete/aggretate for the pier section but the wide base square will then float on the concrete/fit the base hole. 20141021_201618 by Nick and Sandrine, on Flickr There's a few non-straight edges that need to be filled. The idea is that the rings will be cut with a hinge so that the two pieces will break apart. 20141021_201640 by Nick and Sandrine, on Flickr I'll also add wire around the former to take some of the load of the concrete too.
You might find it easier to pour the base first, then the pier. If you pour the two within (about) 3 days, the concrete will fuse to a homologous unit as it hydrates. You could put in a "kicker" to give a starter for the pier, which will help locate the pier later. It will make it easier to get a good finish on the base and to get all the concrete well compacted. The pier will have quite a pressure at the bottom, so you need plenty of support, or the concrete will simply blow the shuttering out. Personally, I'd be tempted to make some frames out of 3 or 4 by 2 to hold your shuttering together. I don't think I'd trust the OSB rings to hold. Finally, I'd put some support in for the pier shuttering and wouldn't trust that it will float on the concrete and still remain vertical.
My thinking on that was to use wire loops to hold the shuttering together - but I will take you advice I'll add some additional containment support and a vertical supports. At the base I'll use wood struts to hold the pier up in a set position these will extend out beyond the hole and then the vertical supports will then attach to them. The base will be attached to the shuttering. My plan is: 1. Dig the hole 2. Place broken bricks at the bottom, test place the components and mark the top level of where the base concrete should be. 3. Place rebar in (this will have been bent & tied into shape already.). It should sit correctly. 4. Pour base - using a patter to move it as it's being poured to help release air bubbles. 5. Once at the desired level, stop and give a final patting and levelling out, have lunch & cuppa, then give a second patting/levelling 6. Place former with the support structs etc. in place, add weights to prevent the concrete from blowing out. 7. Pour pier using a stick to move the concrete around and to pat it down inside the pier former. Use a torch to look down there lol. 8. When at the top - insert the threaded rods bolted into position with the top cover - this provides the basic level and spacing for the bottom brake discs (the discs are used as a levelling system with adjustable bolts between them to provide a level mount point.) 9. Leave for the remainder of the day 10. Place tarp plastic sheet over the top to protect from any heavy rainfall on the pier and base. I'll be around to keep an eye on it - I have a few days vacation I need to take. After a couple of days I think it will be safe to leave to stand on it's own to finalise the setting. Any idea how long I should leave the former on? Longer the better? My thinking is that after a 4 days it should be ok to strip the former off. So if I pour on the tuesday.. I can strip it off on the following sunday.
It might be worth looking at hiring a vibrating poker to get the air out... it's a lot less effort than tamping it by hand. I'd be concerned that a mix that is wet enough to work easily will be too fluid to properly support the form for the pier and weigts and as you are planning. Usually, you'd expect to ease the shuttering a day or two after pouring and then remove it completely a couple of days later. You're right to cover it protect it from rain until it's set. In summer you'd also want to stop it from getting too dry for the week or so after the initial cure, but I doubt that will be an issue this time of year.
Wonder if the SDS on chisel action would do - the chuck could hold a section of metal and it would only vibrate and not rotate.
So everything is ready.. got the mixer hire ready (hired two days in case of any issue, hope weather isn't too bad..). Still have a couple of things to sort out but almost there Planned todo the pour next week