At the heart of the Extruded concrete process, is the concrete extruding machine. These were originally developed in Australia in the late 1970's early 1980's.
Concrete is mixed and fed into the extruding machines hopper. Early
machines used a reciprocating ram to push the concrete through a shaped
form. These forms are interchangeable, so that different kerbing
profiles can be produced from the same extruding machine.
This
product, when combined with concrete stamping and colouring from the
fledgling pattern imprinted concrete industry, was ideally suited for
decorative edging in gardens and along driveways.
The product
quickly caught on in Australia and soon migrated to the USA, where
operators and engineers got together and re-engineered the original
equipment.
The reciprocating ram design was replaced by a
rotating screw design and then with a twin auger design to give a better
quality product that required less manual trowelling.
These
machines operate like large food mincers, with not one, but two rotating
screws, turning in opposite directions to take the concrete in from the
hopper and then force it out through the slip form, in a continuous
motion. Providing a constant throughput, rather than in blocks like the
ram machines, meant a smoother better quality product, requiring less
reworking.
To see the extruding process, click on this link.
The Installation Process for extruded concrete is outlined on the Installation page, either click on this link or the Installation button on left.
The process for applying the colour and hardener and the imprinting is very similar to that used for Pattern Imprinted concrete
Home owners in the USA quickly saw the labour saving benefits of this decorative concrete edging. Along with its visual attractiveness, its effectiveness as a weed and grass barrier, it is also a fantastic labour saver, doing away with hours of tedious manual edging.

To learn more about concrete and its history click on this link. All about Concrete