Comments on: Walking Sponge Shocks Science (Dec, 1933)

By: Torgo

Torgo — Sun, 13 Jul 2008 01:11:03 +0000

I too thought that graphic was a guy working with the sponges.

It looks like sponges doing the limbo.

By: ratpack

ratpack — Sat, 12 Jul 2008 23:21:41 +0000

I was just talking to my brother that works in cement and he told me one of the new trends is to use broken up concrete in place of flagstone to make walls and driveways.

By: ratpack

ratpack — Sat, 12 Jul 2008 08:42:23 +0000

Using broken up concrete for fill material is a common practice even today just not normal exposed.

By: Blurgle

Blurgle — Fri, 11 Jul 2008 20:53:45 +0000

As for that floor, it’s also less sturdy because water will seep through the seams and cause all kinds of problems from lifting to instability to even frost heaves in colder climates. An all-around dumb idea, especially for a surface that has to support a significant amount of weight.

The writer also seems to have confused cement and concrete.

By: Blurgle

Blurgle — Fri, 11 Jul 2008 20:49:48 +0000

“Creep” is right: according to one paper, walking sponges move at the rate of four millimetres – about a sixth of an inch – per day.

By: Kruk

Kruk — Fri, 11 Jul 2008 15:39:07 +0000

They’re putting fresh concrete around the sponges to keep them in place.

By: jayessell

jayessell — Fri, 11 Jul 2008 15:10:48 +0000

Ray! The sponges ‘migrated’ about a foot and a half!

By: Al Bear

Al Bear — Fri, 11 Jul 2008 13:35:30 +0000

That’s why you see 29,000 ads online for free broken concrete! At first I thought the concrete was the sponges http://detroit.craigslist.org/zip/740904077.html

By: StanFlouride

StanFlouride — Fri, 11 Jul 2008 12:34:28 +0000

Amusing juxtaposition.

The idea of using old and new concrete (which even today costs about $6 a bag) is not a good one, the concrete will crack because the old/new interface will be a weak point. Especially so for a garage floor with cars driving over it.