UHPC 3D printing

It is interesting to see today what printing results universities and printer manufacturers achieve.

The results are an interplay between printer technology and material technology. In my opinion today, very good results are achieved in the design areas with the printers, but many problems still have to be solved in professional architectural building construction.

There are

Compressive strength

The standard concrete reaches its maximum compressive strength after 28 days. For the printing technology unacceptable, here must be helped with accelerator. Printing speed and strength development must be matched and optimized without loss of strength.
UHPC Ultra High Performance Concrete can be a solution. Strengths of over 200 MPa can be achieved here. Already during the UHPC binder production, we can adjust the strength development, as well as the flow characteristic. The addition of commercially available additives is no longer necessary.

Print speed

Of course you want an optimum speed, you want to process a large amount / weight of concrete in a very short time. The concrete should be able to support itself after a very short time and be load-bearing for ceiling elements.
With UHPC materials, large amounts of material are already processed in a short time using the wet and dry spraying process. The consistency of the UHPC print material can be adapted to the printer characteristic. UHPC materials already develop high strength values in short time in the standard qualities. However, this time can be extremely reduced by changing material production.

Statics

The print heads are usually small in diameter and the applied wall thicknesses compared to a masonry or a finished concrete wall are very thin. Static load-bearing walls can be printed for several floors, or double-skin walls must be printed in order to achieve a structurally stable construction. Do I have to print double-shelled?

Heat / cold insulation

If I print with a standard concrete I do not achieve any insulating properties. So I have to print double-shelled and fill the cavity with insulation material or retrofit an insulating layer from the inside.
At the moment we are the only ones who are able to combine a high pressure resistant material with an insulating material. This combination material is also pumpable.

Steel girders, reinforcements

Even with 3D printing, you can not ignore reinforcements and support structures, or you can remain eternally restricted to small, simple and low-rise building constructions. How can I optimally combine carrier structures, steel reinforcements with a single printing process?

Last but not least interesting design

So far I have seen the obligatory pressure bulges on all prints. For the beginning, this may be fine but soon you should have printing technologies that ensures a sharp-edged pressure even on the wall corners. A rework of the walls in the flat areas to get is cost and time consuming. Of course, when I use the printing technology, I also want to print exceptional geometry and thin-walled constructions.

I have a note at the end

If all my misgivings can be wiped out the question remains if I want to print a large building, I need a fairly large printer technology which is not even built and dismantled and I need a very fast continuous flow of material to the printer when the printer should work quickly.

I do not want to know misunderstood. I think 3D printer technology is very interesting for the future and I know that some engineering companies are working on technical solutions. As part of our material development, we also work on a flexible, extreme fast-curing, high-compressive strength material for the printer producer. In close technical agreement with the respective printer manufacturer, we can adapt our UHPC materials to the requirements and provide test material to the printer manufacturer.

UHPC - Facades and Balconies

Many facades of public buildings such as
train stations, airports, banks, administrations,
etc. have almost incredible design in addition
to the necessary thermal function.
Then there are the steel and glass facades,
admittedly they fulfill their function perfectly,
but that's pretty much all that can be said
about them. And there are the old facades
that have aged with pride, which are made of
stones with some figures that bear history.

Each of these facades can tell a story, which
one can certainly not say of glass and steel
facades.
UHPC concrete can perfectly combine the
modern with the proud old design. UHPC
concrete is a modern material for the future
with incredible properties. It offers flexibility
in design, security in temperature and wear
resistance, durability in extreme strength and
very high resistance to almost all environmental
influences, detail in design, easy to use
compared to other materials, it can be processed
on site worldwide.

Facades of houses and balconies were almost
always characterized by their marked simplicity.
For some years now, more and more architects
and designers have been dealing with this area
and also because of the climate discussion.
Today you can see more and more interesting
solutions for facades and balconies of residential
buildings. Simple smaller and larger rectangular
balconies are disappearing more and more and
are being replaced by new balcony geometries.
The old idea of ​​greening facades is increasing
in urban centers. Today it is called the vertical
garden. In the course of this development, the
balconies also became gardens and, for some
architects, veritable forests.

Here too, UHPC concrete offer architects and
designers a variety of new technical and design
options. Due to the extremely high strength
values, balcony slabs can be made much thinner
than with a standard concrete or the balcony area
can be increased significantly with the same slab
thickness as with a standard concrete. As with
the facades, in addition to the strength, the

extremely high resistance to environmental
influences and the resistance to fire is a factor
of great interest.

UHPC/Asphalt system versus concrete for pavement, industrial flooring and roads

What is UHPC Phalt?

UHPC Phalt is a grouted macadam comprising 
an open graded asphalt that is flooded with high 
strength microsilica based mortars. The open 
graded asphalt is mixed to a design mix at a 
local asphalt plant and delivered to site in tipper 
trucks. It is placed via traditional paving techniques.

The UHPC Phalt mortars are delivered in 
1 tonne bags and mixed via a continuous flow 
pump machine. The mortar is mixed for a certain 
amount of time to achieve correct viscosity then 
flooded via a large hose onto the asphalt matrix.

How does the whole construction 
thickness fit together?

UHPC Phalt can be laid at depths of 30 mm / 
1,18 in upwards (typically maximum depth used 
is 40 mm / 1,57 in). UHPC Phalt is the top layer 
of the pavement that is supported by a basecourse 
layer. The basecourse layer can vary dependent 
on environment and loadings, internal or external 
applications. Preferred basecourse materials to 
support the UHPC Phalt topping are high modulus 
macadam basecourse or Foamix recycled binder 
course. CBM bases are ideal for use for large 
internal areas. 
The UHPC Phalt pavement structure (DPH + 
Basecourse) is laid onto varying depths of Type 1 stone/capping dependent on the CBR value of 
the sub-grade. 

Advantages of UHPC  Phalt

• Very high load carrying capacity

• Frost and rew resistant

• Jointless laying

• Quick installation

• High early strength

• Temperature resistant from - 60°C/-76°F - 90°C/194°F

Where is UHPC Phalt used?

• Airports
• Ports
• Lorry marshalling areas
• Service yards
• Acces roads
• Bus stations / depots
• Waste management facilities
• Car parks
• Indoors for warehouse floors
• Anywhere that concrete is conventionally used 
  
  
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Corrosion problems at offshore wind turbines solved with UHPC concrete

You have the solution already built in your
wind turbine system UHPC Ultra High
Performance concrete material was already
used in the first wind turbines and has been
stable to date and not replaced.

UHPC is absolut seawater resistant and you
can cast it into the seawater if necessary. No
elaborate preparation is necessary and the
corrosion protection will last for at least 100
years without having to be repaired.
Most system suppliers for offshore wind
turbines have known this for a long time.
 
The UHPC material would have to be
modified a bit, that's all.
We modifed it and it work together
with a simple installation system perfect.

The assembly costs and the operating costs
for a complex anode/cathode system is
several times higher and this electrical
system must be monitored regularly.

Well, there are several ways to tackle the
corrosion problem
- You let it rust because the system is already

   so old
- You can apply an extremely complex anti-
   corrosion paint system. Very expensive and
   the durability is extremely limited.
- UHPC is applied to the steel structure as a
   protective layer.
   A relatively simple and safe installation with
   a durability of more than 50 years
- UHPC is used as a constructive measure to
   improve or stabilize the load-bearing capacity
   of the foundation
- UHPC is brought up as a constructive measure
   in connection with the design of an artificial
   reef around the foundation in order to improve
   the situation of the marine fauna.

Concrete of very high quality cement and desert sand, it works

It is possible to use desert sand as a building sand. Many will cry out and say that will not work. There are so many ancient arguments that are not and of course the international building standards. 

But what can we say, we took a new developed UHPC cement binder into the desert including a few bottles of water and a commercial mixer. We mixed our cement binder with nature desert sand (not cleanded not sieved) and water and after 24 hours we had a strength of 40 MPa and after 28 days more than 70 MPa. We are sorry dear experts and standards. Now we are working on the second generation of desert sand binders, which will become even more effective in terms of technical quaility and flexibility of handling.

Desert sand concrete could be used in many areas such as harbor construction, road construction,

airport construction, architectur and design.

In the construction of the Burji Khalifa approximately 257,500 qqm of sand were used, which corresponds to a weight of 396,000 tons.
This amount of sand could have been taken from the desert and it would have cost - nothing.

Some Arab states are showing great interest in this special UHPC cement binder. It can be very beneficial in helping to rebuild some Arab states or provide new architectural solutions.

If we find the right partners, the UHPC desert sand binders should be producible in every state with desert. Especially in states that have problems with the procurement of river sand but have a desert connection should be the desert sand binder an advantage. The local nature would thus be protected from considerable damage.

See also our UHPC desert concrete presentation