some thoughts from Dozer
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Use a Spacer under Rebar Framework

image dsc20578.jpgThere was a write up a while back that mentioned the idea of using pieces of red brick as a spacer under a rebar framework to keep it in the middle of the concrete pour. use of spacer to reinforce concrete. There was recently a driveway pour going on at a friend’s house, and I wanted to observe just how it is done (without using a spacer).

image dsc20577.jpgIf you go with the normal method of concrete pours, the rebar framework is not left to sit on the sand foundation. The cement workers will first pour the concrete, then pull up on the framework to set in approximately 1/2 way up in the pour. Granted, it isn’t a very exact way of doing it.

image dsc20587.jpgHere is another shot of this ‘pull up’ move. On this project they were pretty good about making sure they didn’t leave the framework lie on the sand foundation.

The argument against using a spacer under the rebar framework, is then you need to set the spacer to have a height of 1/2 way to the ultimate thickness of the pour. Since much of this, as in all construction things Thai, is done by feel, they (in the construction industry) don’t feel the need for spacers.

image dsc20596.jpgHere is a red brick being used to indicate the ultimate height of the pour.

I like the idea of using a height indicator throughout the pour (as shown above) and a spacer (red brick or any other handy material) below the framework. Keep in mind that the cost of steel has doubled in the last year, and it is the most important ingredient to getting a strong pour. All this is consistent with the previous article, with two clarifications — you also need a height indicator so the lower spacer can be set 1/2 way from the top and — if spacers aren’t used the workers should set the framework manually by eye.

I mentioned this idea to another construction foreman and he thought it was a good idea. It is something that if you want to have done on your project you just need to mention it. The major advantage is you reduce the reliance on the worker’s eye to set the steel in the correct place.

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