Concrete Stripping Tools

[Numanator]

Hi everyone,

I just started working at a soil/concrete testing lab and have been using the hand stripping tool to get concrete cylinders out of the molds (mostly 4"x8" cylinders, but also get some larger and smaller ones). Our company has had a recent influx of concrete breaks (compression tests) and i was wondering if there are any other tools that can be used to strip the molds off without damaging the cylinders (it is time consuming to strip off 150+ molds during the week). Also any advice, tips or tricks to speeding up the process of stripping the molds off would be greatly appreciated. Also, are there any ASTM or standardized specifications as to how a mold is stripped those would also be helpful. Thanks!

 

[Ron]

Air stripping works fine. Put a small hole in the bottom of the mold then put an air blower onto the hole opening and the mold will be pushed up by the air pressure. I would caution you to use a guard over your hand for when the mold ruptures (as happens occasionally) and to use eye protection.

You will need to cover the hole when you re-use the molds to prevent water loss as required by standards.

 

[BigH]

Ron, don't some of the more robust reusable plastic molds have the air holes already in the bottom? In these cases, you need to put masking tape over the hole on the inside. For years now (all my time in Asia) they are using reusable steel molds - that come apart. 150/week? We were doing 150/day . . .

 

[Ron]

BigH...yes, there is a reinforced circle in the bottom of the mold for this purpose. The hole is not provided, but the first use cures that!