[PSUBS-MAILIST] concrete

[hank pronk]

A six foot od sphere built in 1.25in thick steel would be equal in weight to 4in thick concrete.  I would not ever expect 4in concrete to compare to 1.25 steel.  But, it would be interesting to know where the concrete stands in comparison.
Hank 
--------------------------------------------
On Fri, 4/11/14, Marc de Piolenc <piolenc at archivale.com> wrote:

 Subject: Re: [PSUBS-MAILIST] concrete
 To: "Personal Submersibles General Discussion" <personal_submersibles at psubs.org>
 Received: Friday, April 11, 2014, 9:59 AM
 
 A huge amount of work was done on
 concrete for pressure-resisting structures, including long
 term, deep exposure tests, by the US Naval Civil Engineering
 Laboratory. Most of the reports are available for
 downloading free of charge from DTIC.
 
 Excellent results were achieved with concrete having NO
 reinforcement. There has been limited work done with
 prestressed concrete and even less done with reinforced
 concrete and ferrocement, which can reasonably be expected
 to give much more efficient and distortion-tolerant
 structures.
 
 Marc
 
 On 4/11/2014 8:25 PM, hank pronk wrote:
 > A cheap alternative to a super strong sphere hull is
 re-enforced concrete. I feel like hiding under a blanket
 while I say this,lol.  I know it is way out there, but
 concrete is super strong under compression.  It is not
 so good for impact resistance.  Concrete is a very easy
 material to work with and form into a sphere shape.  I
 have no idea what thickness would be needed.  Properly
 engineered I would trust it.
 > Hank
 > 
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