In case anyone is interested, I cast a sample panel with 1:1
sand/cement and 2.5% chopped alkali-resist glass fibres from Fibre
Technologies International, see http://www.fibretech.org, 75 quid for a
20kg bag, the smallest they could supply. 10kg sand, 10kg cement and
500g fibre made a panel (well more like a paving slab) 30mm thick and
approx 0.25 sq meters size, weighing, unsurprisingly, just over 20kg.
The resulting panel was quite impressive, although not really big
enough to test tensile stresses much. It certainly "seems" strong,
which is as scientific as it gets at the moment. Although 1:1 mix, no
signs of cracking (former was open on two sides) which a mixture
without the fibres would have done.
This is for the thin strong wall previously discussed. Since the cement
ratio is high, obviously such panels are not as cheap as one would
like.
Apparently this stuff is cutting-edge technology for the building trade
!
Cheers,
Simon.

sm_jamieson wrote:
In case anyone is interested, I cast a sample panel with 1:1
sand/cement and 2.5% chopped alkali-resist glass fibres from Fibre
Technologies International, see http://www.fibretech.org, 75 quid for a
20kg bag, the smallest they could supply. 10kg sand, 10kg cement and
500g fibre made a panel (well more like a paving slab) 30mm thick and
approx 0.25 sq meters size, weighing, unsurprisingly, just over 20kg.
The resulting panel was quite impressive, although not really big
enough to test tensile stresses much. It certainly "seems" strong,
which is as scientific as it gets at the moment. Although 1:1 mix, no
signs of cracking (former was open on two sides) which a mixture
without the fibres would have done.
This is for the thin strong wall previously discussed. Since the cement
ratio is high, obviously such panels are not as cheap as one would
like.
Apparently this stuff is cutting-edge technology for the building trade
!

Better than accoustic plasterboard?

Weatherlawyer wrote:
sm_jamieson wrote:
In case anyone is interested, I cast a sample panel with 1:1
sand/cement and 2.5% chopped alkali-resist glass fibres from Fibre
Technologies International, see http://www.fibretech.org, 75 quid for a
20kg bag, the smallest they could supply. 10kg sand, 10kg cement and
500g fibre made a panel (well more like a paving slab) 30mm thick and
approx 0.25 sq meters size, weighing, unsurprisingly, just over 20kg.
The resulting panel was quite impressive, although not really big
enough to test tensile stresses much. It certainly "seems" strong,
which is as scientific as it gets at the moment. Although 1:1 mix, no
signs of cracking (former was open on two sides) which a mixture
without the fibres would have done.
This is for the thin strong wall previously discussed. Since the cement
ratio is high, obviously such panels are not as cheap as one would
like.
Apparently this stuff is cutting-edge technology for the building trade
!

Better than accoustic plasterboard?
I guess acoustic plasterboard is just heavy plasterboard. The
fibre-concrete is certainly heavier than that, so I guess it would be
better.
Simon.

sm_jamieson wrote:

In case anyone is interested, I cast a sample panel with 1:1
sand/cement and 2.5% chopped alkali-resist glass fibres from Fibre
Technologies International, see http://www.fibretech.org, 75 quid for a
20kg bag, the smallest they could supply. 10kg sand, 10kg cement and
500g fibre made a panel (well more like a paving slab) 30mm thick and
approx 0.25 sq meters size, weighing, unsurprisingly, just over 20kg.
The resulting panel was quite impressive, although not really big
enough to test tensile stresses much. It certainly "seems" strong,
which is as scientific as it gets at the moment. Although 1:1 mix, no
signs of cracking (former was open on two sides) which a mixture
without the fibres would have done.
This is for the thin strong wall previously discussed. Since the cement
ratio is high, obviously such panels are not as cheap as one would
like.
Apparently this stuff is cutting-edge technology for the building trade
!
Cheers,
Simon.

Out of interest, why 1.3:1? Presumably youre loooking for max poss
strength, but doesnt 1.3:1 microcrack badly, reducing its strength
advantage?

Your fibre cost is high, but that will make a lot of cast crete. Last
time I was quoted something like £2 for a bundle of polypropylene.


NT

wrote:
sm_jamieson wrote:

In case anyone is interested, I cast a sample panel with 1:1
sand/cement and 2.5% chopped alkali-resist glass fibres from Fibre
Technologies International, see http://www.fibretech.org, 75 quid for a
20kg bag, the smallest they could supply. 10kg sand, 10kg cement and
500g fibre made a panel (well more like a paving slab) 30mm thick and
approx 0.25 sq meters size, weighing, unsurprisingly, just over 20kg.
The resulting panel was quite impressive, although not really big
enough to test tensile stresses much. It certainly "seems" strong,
which is as scientific as it gets at the moment. Although 1:1 mix, no
signs of cracking (former was open on two sides) which a mixture
without the fibres would have done.
This is for the thin strong wall previously discussed. Since the cement
ratio is high, obviously such panels are not as cheap as one would
like.
Apparently this stuff is cutting-edge technology for the building trade
!
Cheers,
Simon.

Out of interest, why 1.3:1? Presumably youre loooking for max poss
strength, but doesnt 1.3:1 microcrack badly, reducing its strength
advantage?


Tell me more, I'm new to all this.
1.3 ? You're including the weight of the fibres ?
I understand the fibres prevent cracking, but I don't know if this is
the same as
preventing micro-cracking ?
I understand for max strength you need max cement without the cracking.
What mix would you suggest ? If more sand will improve things,
obviously that's good
as it will cost less !

Your fibre cost is high, but that will make a lot of cast crete. Last
time I was quoted something like £2 for a bundle of polypropylene.


NT
I believe glass fibres are better at reducing cracking since they flex
less than polypropylene.

Cheers,
Simon.

In article .com,
sm_jamieson wrote:
In case anyone is interested, I cast a sample panel with 1:1
sand/cement and 2.5% chopped alkali-resist glass fibres from Fibre
Technologies International, see http://www.fibretech.org, 75 quid for a
20kg bag, the smallest they could supply. 10kg sand, 10kg cement and
500g fibre made a panel (well more like a paving slab) 30mm thick and
approx 0.25 sq meters size, weighing, unsurprisingly, just over 20kg.
The resulting panel was quite impressive, although not really big
enough to test tensile stresses much. It certainly "seems" strong,
which is as scientific as it gets at the moment. Although 1:1 mix, no
signs of cracking (former was open on two sides) which a mixture
without the fibres would have done.
This is for the thin strong wall previously discussed. Since the cement
ratio is high, obviously such panels are not as cheap as one would
like.
Apparently this stuff is cutting-edge technology for the building trade
!

Isn't this the way they make promenade tiles which have been around for
many a year? GRP reinforced concrete?

--
*Cover me. I'm changing lanes.

Dave Plowman London SW
To e-mail, change noise into sound.

Dave Plowman (News) wrote:
In article .com,
sm_jamieson wrote:
In case anyone is interested, I cast a sample panel with 1:1
sand/cement and 2.5% chopped alkali-resist glass fibres from Fibre
Technologies International, see http://www.fibretech.org, 75 quid for a
20kg bag, the smallest they could supply. 10kg sand, 10kg cement and
500g fibre made a panel (well more like a paving slab) 30mm thick and
approx 0.25 sq meters size, weighing, unsurprisingly, just over 20kg.
The resulting panel was quite impressive, although not really big
enough to test tensile stresses much. It certainly "seems" strong,
which is as scientific as it gets at the moment. Although 1:1 mix, no
signs of cracking (former was open on two sides) which a mixture
without the fibres would have done.
This is for the thin strong wall previously discussed. Since the cement
ratio is high, obviously such panels are not as cheap as one would
like.
Apparently this stuff is cutting-edge technology for the building trade
!

Isn't this the way they make promenade tiles which have been around for
many a year? GRP reinforced concrete?

I think that also contains a polyester resin, i.e. its actually a mix
of fibreglass and cement.
Simon.

On 25 Sep 2006 06:16:28 -0700, "sm_jamieson"
wrote:

In case anyone is interested, I cast a sample panel with 1:1
sand/cement and 2.5% chopped alkali-resist glass fibres from Fibre
Technologies International, see http://www.fibretech.org, 75 quid for a
20kg bag, the smallest they could supply. 10kg sand, 10kg cement and
500g fibre made a panel (well more like a paving slab) 30mm thick and
approx 0.25 sq meters size, weighing, unsurprisingly, just over 20kg.
The resulting panel was quite impressive, although not really big
enough to test tensile stresses much. It certainly "seems" strong,
which is as scientific as it gets at the moment. Although 1:1 mix, no
signs of cracking (former was open on two sides) which a mixture
without the fibres would have done.
This is for the thin strong wall previously discussed. Since the cement
ratio is high, obviously such panels are not as cheap as one would
like.
Apparently this stuff is cutting-edge technology for the building trade
!
Cheers,
Simon.

Did you buy if from them directly?

marvelus wrote:
On 25 Sep 2006 06:16:28 -0700, "sm_jamieson"
wrote:

In case anyone is interested, I cast a sample panel with 1:1
sand/cement and 2.5% chopped alkali-resist glass fibres from Fibre
Technologies International, see http://www.fibretech.org, 75 quid for a
20kg bag, the smallest they could supply. 10kg sand, 10kg cement and
500g fibre made a panel (well more like a paving slab) 30mm thick and
approx 0.25 sq meters size, weighing, unsurprisingly, just over 20kg.
The resulting panel was quite impressive, although not really big
enough to test tensile stresses much. It certainly "seems" strong,
which is as scientific as it gets at the moment. Although 1:1 mix, no
signs of cracking (former was open on two sides) which a mixture
without the fibres would have done.
This is for the thin strong wall previously discussed. Since the cement
ratio is high, obviously such panels are not as cheap as one would
like.
Apparently this stuff is cutting-edge technology for the building trade
!
Cheers,
Simon.

Did you buy if from them directly?

I did - I was having great difficulty finding any suppliers, so I went
for the first one.
Most of the glass fibre around is for fibreglass and not
alkali-resistant
I phoned them up - most helpful, suggested the mix, type of fibre etc
for my application. They also suggested a superplasticiser to reduce
the water content (more cost), but I thought I'd start my experiments
without it. I think it is used where very fine moulds must be filled,
and the stuff must flow freely.
On top of the price I mentioned was VAT and delivery - not too cheap
over all.
The fibres actually come from Japan I think - its marked on the bag. I
will check the
actual source, and post it later.
Simon.