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Posted: Tue Apr 01, 2008 11:11 pm
by ammosmoke
MrCrowley wrote:I dunno just seemed like a good idea at the time
I must of thought of it from the logic that the tighter you pack something that goes
boom, the bigger
boom you're going to get 8)
...Which we don't want in this case

Uhhh except for the fact that powder rockets are compacted at with a few tons of force...

Posted: Tue Apr 01, 2008 11:49 pm
by MrCrowley
I was meaning, if the chamber explodes, having a gap between the concrete and chamber might reduce the initial shock and impact on the concrete. It may also give the explosion more room and cause more damage, but it was just a theory.

Posted: Wed Apr 02, 2008 12:00 am
by ammosmoke
Oh. Interesting. Somehow I always manage to compare things to pyro in my mind.

Posted: Wed Apr 02, 2008 5:33 am
by Hotwired
MrCrowley wrote:I was meaning, if the chamber explodes, having a gap between the concrete and chamber might reduce the initial shock and impact on the concrete.
However if the reinforced concrete is right next to the ABS then the ABS has no space to expand and rip.
The extra mass would also help with recoil.
But as benstern's said, could be tricky with maintenance.
Posted: Wed Apr 02, 2008 6:30 am
by scottcrete
Don't know if you care.. but the only Job I have ever had besides the military is I was a concrete labor until I was 18 and then a concrete finisher from then on.. The biggest thing is you want a strong mix of concrete.. remember concrete strength comes from the concrete to sand ratio.. and you want to have plenty of aggragate in the mix.. so i would suggest.. a 5 to 1 mix ratio of concrete to sand with 1 shovel of number 67 gravel per 5 to 1 ratio mentioned above.. and you definately want to use the longest fiberglass fibers available to you.. next you want to by chciken wire and form it about 1 inch away from your gun around it.. kinda like a mold.. then this will help in the (if it would explode).. also you could add some number 6 rebar around it.. (every number in rebar) is equal to 1/8" also.. i would suggest that once poured.. if your not pouring some unknown godly ammount.. that you take a hammer and whack away on your forms to get the air bubbles out.. we do (or did) this alot on forms that a pneumatic vibrator will just skae them apart.. because of their delcate nature.. anyways.. they have pencil vibrators too.. that are relatively small.. and about 10.00 for a day to rent at a rental store.. here in america.. but anyways.. you can ask me anything you want... just hollar.. and i will respond when i see it.. and if i dont respond quick enough to this particular thread.. then shoot me a PM
Posted: Wed Apr 02, 2008 7:13 am
by scottcrete
me finishing concrete on a wall.. look how high up I am..lol
I poured this inlet at a power plant in WV
just to show you some of my work.. I will post residential work .. when i get a chance... I have to find pics of it first..
Posted: Wed Apr 02, 2008 7:41 am
by scottcrete
I found it.... by the way.. im only posting these pics.. to show you i know what I am talking about.. but wouldnt that be a nice chamber in the pic above.. what would be your ignitor? a 10000000kw transformer? lol
here are the pics..

driveway we poured 1st pic

another pic.. as we were getting closer to the end.. (notice me in the red shirt bossing)

after i bull floated it.

the end result.. after.. and washing off any debri before showing customer

approach to this driveway.

me applying hardner to this surface ( a monument will stand here ) wood will be removed before the rest of conrete will be poured and stamped.

me floating in the color

me stamping this.. the release is a dirty job..

notice the big stamps weighing in at 50lbs a piece... that makes you tired.

me spraying curing on the slab.. to darken and seal it.

stamped slab sealed.. notice the slanted blocks in the center.. monuments will stand here.

before it was sealed

after it was sealed

notice how it really looks like stone.. but its concrete (i stamped it)

monument company installing the monuments on those slants not stamped

pouring some exposed aggragate

me cutting the joints in it.

gonna be a nice place to fish huh?

joints cut

finished product.. after concrete is washed away.

another view

joiints finished

real close up

finished sidewalk

finished arbor.. installation to follow below

stamped concrete.. holes around posts are for irigation.. the wood is cedar.. will not rot... plants go in these holes

me stamping it.. throwing color

finished stamping
and now you know.. im not full of dookey.. i know what i am talking about when it comes to concrete,
kapeesh?

Posted: Wed Apr 02, 2008 8:02 am
by Hotwired
Hmm... never knew concrete was sometimes physically stamped on site.
I had thought all concrete moulded pattens were sold ready moulded.
Always something new to learn

Posted: Wed Apr 02, 2008 8:04 am
by scottcrete
any questions about it.. send em my way...
i can walk you through it.. (maybe)
Posted: Wed Apr 02, 2008 8:20 am
by Carlman
thread jacked a bit? lol
nice job mate, all questions should be PMs though
Posted: Wed Apr 02, 2008 8:53 am
by scottcrete
just wanting people to know.. that i do know what i am talking about when it comes to concrete.. and this is a thread about concrete is it not?
Never meant to give the .. thought of hijacking threads.. to anyone.
just wanted him to know this was my field of expertise..
Posted: Wed Apr 02, 2008 1:01 pm
by Rokmonkey
Mmmk, so my roommate and I just talked about for a bit, it is great under compression as was said earlier, not so great tensile, and where it is possible to make concrete to withstand thousands and thousands of psi, it really isn't worth it.
And reinforcing it with rebar, does make it strong, however, what it does is, hold the shape when the concrete breaks and caves, it cracks and you'll lose all pressure, so might as well be ABS then, it holds the concrete in place just with deep cracks.
It's fun to watch under those pneumatic presses.
Posted: Wed Apr 02, 2008 4:27 pm
by DYI
The new plan is to cast a 2" steel pipe inside a 4" steel pipe for a high mix hybrid chamber.
From my understanding, the concrete, reinforced with rebar and mesh, and with added glass fibers for greater tensile strength, should prevent the inner pipe from expanding, and dissipate the energy, as well as saving me in the event of a failure. Sound good?
As far as I can tell, the general opinion is that the original idea (casting a 4" pipe inside an 8" pipe with reinforced concrete) won't work. Is that correct?
Posted: Wed Apr 02, 2008 4:45 pm
by potatoflinger
If you don't mind me asking, what was the incident on Saturday that made you want to use a concrete-reinforced chamber?
Posted: Wed Apr 02, 2008 4:47 pm
by SpudFarm
hey this looks alot like the topic i made about lead and steel pipes
