Written by Don Hourahane, South Africa

In South Africa we have mastered the art of making thinner, tougher, lighter concrete,
similar to the rigid photographic plates that pre-date roll film. Intaglio, one carefully measured step at a time are experimenting with textile concrete to reduce the thickness and therefore the weight to be transported and installed of their product.

The process has world wide appeal, conventional concrete is a 100 - 150 mile delivery
product, reduce the weight by 50% and its a 200 - 400 mile delivery product. As this
web page indicates a CCC Intaglio photograph was courier ed to Germany, for exhibition
at "K" Messe, possibly the world's largest plastics fair.

Thinner and therefore lighter products have to be as strong, preferably stronger than
concrete. When subjected to 3 point bending concrete breaks, the textiles in the concrete
take over the load. The process is known as strain hardening, its described in the
literature as desirable....its why textile concrete is routinely being used.

In textile concrete, as the concrete cracks it transfers the load into the textile layers, in
the case of CCC into the Curv core. Concrete has a density 12 % lower than that of
aluminum, has to be thin for this to be obvious, textile concrete is thin and can be very thin.

A Cemforce-Curv-Cemforce [CCC] plate can have a 2 mm [approx. 1/10 the inch]
Curv core, the CemForce layers are ultra-sonically welded to both sides of Curv. The
CemForce forms one element of the textile concrete surface. If needed both sides of
a CCC plate can have concrete applied and be photo-etched, for use as a division
panel between adjacent booths in a restaurant, for example.

CemForce has a fibrous surface, the fibers are ultra-sonically bonded to the Curv and
protrude from the cementitious surface. They are are finer than a human hair and not affected by the Intaglio process. They are polypropylene, applying a soft flame, they disappear. The fibers will remain in the cement matrix holding the aggregate that forms the Intaglio image in place. The yarns that hold the aggregate in place, are 1 mm in diameter [1/25th] of an inch, they and the fibres bonded to them act like the claws of a ring holding a gem stone in place.

Freeze thaw affects concrete pavers [etc], as is known, concrete when stressed
breaks.

Water that gets into concrete and freezes e-x-p-a-n-d-s, the force applied as
the ice forms is enough to crack the concrete. In stone quarrying, they used
to drill holes, fill them with water, plug them to keep the water in the holes.
Ice as it forms needs 10% MORE room, has to crack the rock or concrete
to get it......

In our paper....Fig 5 shows the tensile strength of textile concrete,
note how it gets stronger ...whereas plain concrete BREAKS. Textile concrete
can resist the force caused by ICE, in part because less water can get in.

The photographic process that we have "all taken for granted" has been around for
150 years, roll film for 100 years, Polaroid briefly replaced the negative & print process,
by combining the two in a pouch. Once the printing process had become digital, it was
not too long before photography followed. Now we have photo-images that could last
100 or more years outdoors in all weathers, take them to the seaside, they will love it.

The Intaglio process and CemForce-Curv-Cemforce, or textile concrete belong together,
the relationship is synergistic, almost symbiotic.

Curv (R) is a product of Amoco fabrics and fibres - Europe, CCC gets made in South Africa.