Thursday, September 4, 2014
Constructing the Telescope Pier
Here’s a drawing I found on the internet. It’s close to what I’m trying to build. The 3’x 3’x 27” block will require about 1222 kgs. of concrete and the tube will require about 166 kgs of concrete. The total is about .70 cubic meters. If I could, I would pour the footing then wait an hour before pouring the pier. This would prevent the concrete in the tube from sagging. The concrete is coming from Yunohira (closest vendor) which is about 45 minutes away. Figuring about an hour to deliver, I’m calculating I have about 1.5 hours to do both pours. If we pour the footing in 15 minutes and then wait 1 hour, then I have 15 minutes to hand shovel and tamp 166 kgs (six 80lbs bags) into the tube…not much time. Adding to the difficulty, I have to accurately align a pier plate in the concrete with true north once the tube is almost filled, finished and leveled.
Why not just mix the concrete yourself? I would if the materials were available. I can’t find a supplier for a large quantity of bags of premixed concrete. The bags that are available are only 10 kgs at about 1000 yen a bag. The bags would require gravel to be added to strengthen the mix. The cost would be close to 120000 ($1200) yen. Having the concrete premixed and delivered only cost around 16000 ($160)…big difference! The weather will play a huge factor in the curing process. The pour will have to wait until the weather is cool and dry…maybe in October. George