Re: Non Metal Machine Bases

Thanks Bill for the thread I was using the wrong description in my
searches as the material used is generally called Polymer concrete. I
then found the following article from the journal of Construction
Engineers.

john

Case study:

Among the newer and promising areas of application of fibre concrete
is the construction of machine foundation blocks.

Machine foundation blocks are generally made of grey cast iron.
However, the high cost, long time of manufacture and the brittleness
of cast iron has led to a search for alternative material. Several
mechanical properties are relevant to the functional and structural
design of machine bases.

The results of an experiment to determine the compressive strength,
flexural tensile strength, fracture toughness and oil absorption of
epoxy glass fibre concrete were interesting in this context.

Material:

The test sample was prepared using a basic mix, consisting of fine
sand, coarse sand, coarse aggregate, high-strength portland cement,
epoxy and hardner. The relative proportion by weight of the
components was 105:110:610:55:57:6.

The mix was arrived at after some preliminary trials and
considerations of economic viability. Ordinary river sand was used
for the mix. It was used as fine sand after being passed through a
600-micron sieve and retained on 150-micron sieve, and as coarse sand
after being passed through a 2.36-mm sieve and retained on a 1.18-mm
sieve. Crushed granite stones passing through a 15-mm sieve and
retained on a 10-mm sieve was used as coarse aggregate. Epoxy used
was Araldite CY-212 and hardner was HT-951 grade. Chopped glass
fibres were used as fibre reinforcement and the fibre content varied
between 0 to 1 per cent by weight of dry material.

The tests were conducted on an Instron machine. Oil and cutting fluid
absorption tests were conducted for size 40 mm x 62 mm x 160 mm.

Results:

The variation of flexural strength with fibre content is shown in
Fig. 1. The load deflection plots as obtained from tests on Instron
machine on notched beams are typical of those shown in Fig 2. The
variation of fracture toughness Kje with fibre content is shown in
Fig. 3. It can be seen that fracture toughness and flexural strength
increased with increase in fibre content.

However, the compressive strength slightly decreased with fibre
content (see Fig. 4). The variation in oil and cutting fluid
absorption tests with fibre contents are shown in Fig. 5 and Fig. 6.
Even though the oil absorption increased slightly with fibre content,
it was within acceptable limits for practical applications. The
behaviour with reference to compressive strength and oil absorption
tests reflects the porosity and adverse effect of having high fibre
content mixes.

Conclusion:

The test data indicate that epoxy glass fibre concrete with 0.5 per
cent fibre content by weight is a promising material for use in
machine foundation.

The writter is a Chartered Structural Engineer.

BACK


In a message dated 1/14/2004 10:27:28 AM Mountain Standard Time,

> johnglynn@e... writes:
> Does anyone know the process for manufacture
> of these bases.
> <
> <
> There is something about this in the files section.
> bill
>
>
> [Non-text portions of this message have been removed]