In a message dated 07/03/03, beezaur@.......... writes:

> I have read about the unreinforced recipe 1:1 sand: cement for piers, but 
> this does not give the bending strength required for my slab.  I am 
> thinking of a more conventional mix using ~1:2:3 cement:sand:pea gravel and 
> a lot of small reinforcement (#3 bar or welded wire fabric).  If I vibrate 
> it well, I should be able to avoid air pockets.
> 
> My main concern is thermally induced noise from reinforcement 
> expanding/contracting differently than concrete.
> 
> Has anyone done or heard about this?  Do you think it would produce 
> internal noise?

Dear Scott,

       If I remember correctly, there was a note by Sean way back saying that 
gravel was undesirable and re-bar was a definite no-no. I understand that 
both can generate noise, with moisture and with temperature changes. I would 
be most surprised if 1:1 sand and cement was not strong enough in practice, 
but I would leave it covered in it's mould for a week. You can expect it to 
take a month to fully cure. Concrete can then be dried out and given a coat 
of something like pool paint to seal it and to reduce any metal to concrete 
corrosion and any moisture changes.

       Have you considered making a T base frame out of say 1.5" black steel 
angle? 1 cross bar at the top and bottom and two long parallels for the II in 
the T. Make the vertical hoop and cross bar out of the same material. You can 
bolt and epoxy the joints, or alternatively arc weld them.

       Regards,

       Chris Chapman
In a message dated 07/03/=
03, beezaur@.......... writes:



I have read about the unrei=
nforced recipe 1:1 sand: cement for piers, but this does not give the bendin=
g strength required for my slab.  I am thinking of a more conventional=20=
mix using ~1:2:3 cement:sand:pea gravel and a lot of small reinforcement (#3=
 bar or welded wire fabric).  If I vibrate it well, I should be able to=
 avoid air pockets.



My main concern is thermally induced noise from reinforcement=20

expanding/contracting differently than concrete.



Has anyone done or heard about this?  Do you think it would produce=
=20

internal noise?




Dear Scott,



       If I remember correctly, there was=20=
a note by Sean way back saying that gravel was undesirable and re-bar was a=20=
definite no-no. I understand that both can generate noise, with moisture and=
 with temperature changes. I would be most surprised if 1:1 sand and cement=20=
was not strong enough in practice, but I would leave it covered in it's moul=
d for a week. You can expect it to take a month to fully cure. Concrete can=20=
then be dried out and given a coat of something like pool paint to seal it a=
nd to reduce any metal to concrete corrosion and any moisture changes.



       Have you considered making a T base=
 frame out of say 1.5" black steel angle? 1 cross bar at the top and bottom=20=
and two long parallels for the II in the T. Make the vertical hoop and cross=
 bar out of the same material. You can bolt and epoxy the joints, or alterna=
tively arc weld them.



       Regards,



       Chris Chapman