Early tech spec 3developers

1. Machine Specifications
Technical specification of the machine:
I Printer P1 (16m x 9m x 2,7m)
I Concrete pump (13 kw, 20 bar, 7-180 l/min,
30m hose)
I Nozzle (Φ 20, 30 or 50mm)
I Concrete mixer (60-90 l/min, 4kw)
I Air compressor (5 bar, 20l capacity)
Wall Strengths
The strengths of the wall depends on the types of cement
mix used and we can use a whole range of different
materials and testing is still going on and with different
additives, here is a sample of test with one of our lower
quality materials.
Materials
All concrete materials are sourced in accordance with the
appropriate British Standard and in accordance with the ACP
performance specifications.
I Concrete typical 28 days strengths are 60N/mm²
I Concrete strength at transfer 30 N/mm²
I Water cement ratio 0.30 Maximum This includes are quick
dry mix
I Reinforcement typically 9.3mm dia. prestressing strand
I We can use a number of materials, quick drying adhesive
can be added to harden cement as we go along.
Tolerances
Cross-sectional tolerances are within limits set out in
clause 6.2.8.3 of BS8110:1997. ACP acceptable
tolerances for standard pressurised units are as follows
I Length -5mm to +10mm
I Width -0mm to +6mm
I Thickness -2mm to +6mm
I Squareness 12mm difference between diagonals
I Socket positions -/+ 10mm
I Lifter position -/+ 100mm
I Flame Spread 4 or less
I Smoke Contribution 0.0 or less
Surface
I Any flat surface can be built on but testing needs to be
completed with regards weight loads and different types of
surfaces.
I Land should be level and straight and it is advised that the
team could dig holes for the foundation and cement them and
finish reinforced concrete slab.
I More test will need to be done to see how the machine adapts
to different surfaces.
Assembly
I A person with sufficient knowledge in
housebuilding and programing in SketchUp, can
learn to print with our printer in a few days. A
mandatory course of training will be provided
to operatives who have satisfied local Health
and Safety and Construction site regulations and
requirements.
I The longest part of current printers is 6 metres
at present. It is possible to make a printer that
has smaller parts.
I Assembly takes 4 operatives from 2-10 hours,
dependent on their knowledge and ability.
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2. Design
All units are designed in accordance with BS 8110 and BS
5502. Unit design is typically to Class 3 with a limiting crack
width of 0.1mm unless otherwise stated.
Not all of the materials are approved for our printers, mixes
would need to be supplied for testing before approval. Around
100 cubic metres of cement for a house of 12m x 8m would
be required to be submitted for testing.
I Maximum built area of printer is 16m x 8,5m. But this
can be increased by moving the printer.
I Holes / routes for plumbing, electrical and plug and go
of fixtures and fittings can be incorporated in to the 3D
CAD design as required so this is built into construction
to minimise builders work for second fix items. Each
house can be built bespoke so that all considerations can
be taken into account by the machine for the particular
build.
I Trusses can be built and printed with the printer creating
a strong surface. Any shape or structure that can be
built with cement can be used and developed by the
printer, usually to a higher standard.
I The current printer model can print up to 2,70m in
height. To print higher the printer can be raised with/on
a support platform/scaffold
I Foundation designs are as normal local requirements for
a single storey brick house.
I A house of 12m x 8m, would need approx. 100-150
cubic metres of material depending on design
I The weight of the ‘ink’ or build material is 2,4 tons per
cubic metre. It is packed in large bags that contain 1
cubic metre of material.
I Each layer would be 15mm in height and would be 3o
mm thick but we can vary this with our extruder based
on conditions.
I Current initial design require reinforcement at 3m (steel
columns or reinforced concrete with steel reinforcing bars
I A current partner we are working with is looking at
including the bars into the print machine design but
tests and meeting with building standards regulators
that the strength in design of concrete pillars is more
than enough strength to exceed building and safety
regulations.
I The technology is being used to build skyscrapers and is
being developed by NASA to build in outer space so its
adaptability is clear.
I The material is mainly cement but we there are additives
available for fast drying applications that allows it to set
faster. Recycled and reclaimed concrete can be used in
the printer after successful granulation as well as well as
lavic ash based products
I The material is an excellent insulator, which allows large
amounts of heat be kept in the house. The material
science team is presently experimenting with various
mixes to improve this process.
Build Details
Residual Risks
I The main cause of risk is the operative controlling the
printer, and the quality of the mix pumped in to the
printer. With the correct training and diligent
operation risk is reduced.
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