Showing posts with label UHPC Installation. Show all posts
Showing posts with label UHPC Installation. Show all posts

Railway bridge repair or new construction with UHPC concrete

One of our many bridge projects we have this year. They are highway bridges and railway bridges. In this case, a railway bridge that was built shortly after the war from simple steel girders and heavy concrete. There are up to 65 freight trains passing this bridge daily.

It is not yet clear if the bridge can be repaired with UHPC or if the bridge has to be completely rebuilt from UHPC. There are still some reports necessary.

The advantage of UHPC in a repair is the UHPC as corrosion protection, as joint and crack filling and as additional static reinforcement can be used easily. The repair time can be minimized by the extremely fast setting time.
In the case of a new building, the size of the bridge can be easily used with a UHPC precast technology, which also reduces the blockage of the rail track to a minimum.

UHPC - Grouting material for the Offshore industry

Our UHPC grouting products are a pumpable and developed for offshore application and has been used widely in connection with structural strengthening of offshore platforms.

Such UHPC grouting products have been used offshore in connection with
  • Strengthening of intact tubular members
  • Reinforcement of joints
  • Repair of damaged members
  • Pile-sleeve connections
  • Strengthening of double skin sections

An example of a spectacular application of such solutions with respect to member repair is for a
member having experienced hydrostatic collapse, where the member was re-inflated and filled with ultra high performance grout. In another case our solutions were applied in connection with a pile-driving refusal (changing the intended shear key connection to a plain pipe connection). UHPC grouting high strength material was used as grout material in stead of the intended conventional grout. In the above selected cases the design strength of the members was re-established due to the extreme effect offered by high strength materials and at the same time the solutions was economically attractive.

One of the main advantages of using grouted solutions in connection with repair is the easy
accommodation of geometrical irregularities. Structural components subjected to some kind of damage (from installation, impact or accident) often show some dents or imperfections. The use of ultra high performance grout in connection with repair improves the performance hereof as the UHPC grout serves not just as a filling material but as a strong structural component.

Our UHPC grouting products are suitable for casting both above and below water. Due to viscous consistency of the mixed materials there is no risk of washing out cement particles or mixing with water when cast below sea level. 

The UHPC grouting products for Offshore have been developed having very low shrinkage so that
the grout and surrounding steel remains in physical contact after curing. Further, these products has been developed to show limited heat development during the hardening process eliminating the risk of thermal cracking.

The jungle of short names for high strength concrete

I would like to try to clarify the jungle of
short names of high strength concrete
 names in the literature. The reason for
this is, that I have once again read a technical
master thesis from the field of civil
construction of a European university and
where only with short descriptions is
thrown around.

The first high-strength cement binder with a
compressive strength of well over 100 MPa
was developed in Denmark more than 30 years
ago. The aim of the development was to
produce a high-strength cement binder, which
was also very successful. At that time, the
focus was on the binder and not on possible
aggregates or reinforcement systems. For this
reason, an extremely high-strength binder was
always used in all the discussions.
Much later, to the dismay of many, the term
UHPC appeared in the literature. In our opinion,
this term UHPC cannot be clearly defined. It
also seems to be a fad to further water down this
term and everyone who thinks he has understood
ultra high-strength concrete creates his own short
form.


I would like to list the short forms here and provide
appropriate comments.

The UHPC binder is made of a special grade of 
cement, microsilica and superplasticizer.

UHPC    Ultra High Performance Concrete

Consists of UHPC binder + aggregates, which
can have different material grades and grain sizes
There are no standards which additives and surcharges of
which material quality and grain size must be used.

HPC    High Performance Concrete

Consists of cement + aggregates + additives
There are no standards which additives and surcharges of 
which material quality and grain size must be used. Likewise, 
there are no standards about the technical properties.

RHPC    Reinforced High Performance Concrete

Consists of cement + aggregates + additives and
unspecified reinforcement
There are no standards which additives and surcharges of 
which material quality and grain size must be used. Likewise, 
there are no standards about the technical properties. There
is no specification for material quality, dimensions and 
quantities for the reinforcement

HRUHPC    Heavy Reinforced Ultra High Performance Concrete

Consists of UHPC binder + aggregates, which
can have different material qualities and grain
sizes, and an unspecified reinforcement
There are no standards which additives and surcharges of 
which material quality and grain size must be used. 
Likewise, there are no standards about the technical 
properties. There is no specification for material quality, 
dimensions and quantities for the reinforcement

SFRC    Steel Fiber Reinforced Concrete

Consists of cement + aggregates + additives +
steel fibers
There are no standards which additives and surcharges of 
which material quality and grain size must be used. Likewise, 
there are no standards about the technical properties. For the 
fibers there is no specification of material quality, dimensions
and quantities.

RPC    Reactive Power Concrete

Consists of cement + sand + quarz powder, 
silica fume, steel fiber and superplasticizer
There is no standards of the quality of cement, sand 
silica fume must be used.


Anyone, university, technical literature or expert, will
take part in this Babylonian jumble without bothering
to really specify UHPC. At the moment many talk
about many things, but only a few about the same.

In my opinion, there should be only one UHPC binder
quality with one name and what is admixed to like
aggregates, fiber, reinforcements and much more is up
to the user. The UHPC binder manufacturer should only
manufacture according to the UHPC binder specification.

If one agreed internationally on a technical specification,
there would be very few UHPC producers from that day
on and many would have to name their products
differently or dramatically improve their material quality.


www.hhbc-consulting.de
info@hhbc-consulting.de



Mixer for UHPC Ultra High Performance Concrete

What is the use of the best UHPC Ultra
High Performance Concrete product if
you do not have the right mixer to mix
this product perfectly? If possible, a
mixer can handle casting compound,
mortar and Shotcrete mass without it
has an effect on the finished UHPC
product.
There are a lot of different mixer types
in the international market. Some may
mix casting compound, other mortar
compound and yet another Shotcrete
mass. Only a few can mix all the masses
well and few of them can mix the UHPC
products perfectly.
We prefer more than 25 years compulsory
mixers or pan pot mixers called. They
have never disappointed us on all our
international construction sites. They are
very sturdy, at least we use and they are
very easy to handle.

Different mixers can be used for different
requirements and markets.
In general, shaft or pan pot mixers are the
best choice for all applications and markets.
For industrial applications such as Offshore,
wear protection, industrial flooring, corrosion
protection, etc., where the highest quality
requirements are set, the best mixers must
also be used, i.e. pan pot or shaft mixer.
Furthermore, our UHPC requires mortar
qualities for mixing powerful pan pot or
shaft mixers.

When mixing UHPC Cast, we recommend
using pan pot or shaft mixers. It is also
possible to mix with standard UHPC Cast
material. With smaller quantities of UHPC
Cast it is also possible to use a hand mixer.
We have used a large number of mixers
worldwide in our more than 25 years of
assembly work. Most mixers failed because
they are underpowered. It is just a difference
to mix a UHPC or a standard concrete.

For our customers we have put together an
information brochure about mixers, which
you can get from us free of charge in paper
format or as a download.
Laboratory mixing devices can also be used
for small quantities of up to one kilogram of
mixing material or, if the performance is right,
kitchen mixing devices can also be used.
We and our worldwide partners have pan pot
or shaft mixers with different services in our
workshop. You can hire these mixers for
processing on request.
You can also get a list of international mixer
manufacturers with whom we have already
worked.


www.hhbc-consulting.de
info@hhbc-consulting.de




Rehabilitation and restoration of historic constructions with UHPC - part 1

Obtaining historical constructions is an 
important task. Much has already been 
lost through time and war, few of which 
are important to obtain.
we could not produce original materials 
from different time periods, so we can 
not fulfill this part of the restoration of 
historical constructions.

But with UHPC Ultra High Performance 
Concrete, we are able to offer solutions 
to a wide range of problems in conserving, 
reconstructing and restoring historical 
constructions.

UHPC has many advantages for use
  • It can look exactly like limestone, 
    sandstone or granite
  • it can be just as hard as limestone, 
    sandstone or granite
  • It can be made as stones in any 
    measure like limestone, sandstone or 
    granite
  • It can take over any stone surface of 
    limestone, sandstone or granite
  • It can copy extremely accurate copies 
    including traces of use in all the finer 
    points of limestone, sandstone or granite
  • It can be made as a casting material or 
    as a mortar and processed as traditional 
    casting and mortar mass for limestone, 
    sandstone or granite
  • It can be machined with traditional tools 
    depending on the desired hardness.
  • It can have almost the same consistency 
    as plaster and can be processed as well. 
    For extremely high whiteness we added 
    Aalborg White cement to our UHPC binder, 
    the cement grade with the highest degree 
    of whiteness.
  • UHPC can add ductility to modern plastic 
    or ceramic fibers, so the great strength 
    of the material movements of old buildings 
    can certainly go along without the cracks 
    becoming visible.
  • UHPC is impermeable to water from an 
    average layer thickness of 10 mm.
  • UHPC can also be processed under water 
    as cast or mortar
  • However, it is extremely resistant to all 
    types of environmental influences
  • It is extremely resistant to frost and de-icing 
    salt
  • Wood and steel can be cast in UHPC, 
    re-stabilized, restored to their original 
    carrying capacity, and given very high 
    corrosion resistance for many decades

UHPC is not magic material it is based on a 
particular nanotechnology and the right recipe 
for the right mix, for the right aggregates, for the 
right material quality.

With UHPC we can mix almost anything, old 
minerals, old textiles, old wood, old hemp, old 
pigments, old ground rock meal - just about 
everything.


www.hhbc-consulting.de
info@hhbc-consulting.de




UHPC® Architecture on the sea coast


The big cities on the coasts and rivers have
big problems for the future. A problem is the 
lack of natural space for the permanent 
expansion of cities. Building ever higher 
skyscrapers is not a solution in the long run. 
One solution is to expand the construction 
site by adding fillings in the coastal area, 
as we see in Dubai and Singapore, among 
others. Another solution to the problem is 
the very old traditional construction of pile 
dwellings and houseboats, as they have 
always done in Asia.

Modern architecture has been thinking 

about its designs for a long time with interesting 
designs and projects about future life in coastal 
and river areas. Here, the old living concepts 
are reinterpreted. New materials such as 
UHPC® concretes can easily incorporate 
existing local living concepts and constructions 
and implement them in permanent concepts. 
UHPC® offers absolute seawater resistance with 
extremely high strength. Light, thin but 
high-strength constructions can be combined 
with local traditional materials such as bamboo.

Floating residential and industrial concepts can 

also be realized with UHPC®, and not just above 
water. The first underwater concepts have 
already been implemented worldwide with new 
hotel concepts. Recent plans also include 
entire artificial islands on which hospitals, 
workshops, hotels, kindergartens, residential 
complexes including leisure facilities are built.
Some international architecture firms are 

interested in using UHPC® Ultra High 
Performance Concrete in their living concepts, 
because the advantages of this material are 
unique in their variety and quality.

UHPC
® offshore constructions are already in 
use in areas with extreme environmental 
conditions. UHPC® is very wear-resistant, 
among other things, moving ice masses is 
not a real problem for a UHPC® construction. 
UHPC® materials have no pores, are therefore 
extremely corrosion-resistant and offer an 
extremely long repair-free service life.


www.hhbc-consulting.de
info@hhbc-consulting.de







UHPC Rehabilitation of concrete structures


Due to the old age and the increased and
rapidly increasing loads, for example due
to traffic and environmental influences,
an enormous number of concrete structures
are in need of renovation or have to be
completely replaced by new, more robust
structures. The renovation effort in the
infrastructure area is gigantic worldwide.
The focus here is on bridges.

UHPC Ultra High Performance Concrete
materials have many decisive advantages
over standard concretes when renovating
concrete structures. By using UHPC concretes,
material costs, assembly costs and assembly
times can be reduced and the service life of
the repaired concrete structures can be
extremely increased. Standard construction
machines can be used when installing UHPC
concrete.

The goals of repair or repair assembly are in
general

The restoration of stability and a stable concrete 
cross-section
Due to the enormously high strength values ​​of
UHPC compared to standard concrete and its
very fast strength development, the stability of
the construction can be quickly restored.
UHPC mortar, castable and shotcrete materials
can be used.

Increasing the load capacity
UHPC materials offer the structural engineer and
bridge designer the option of significantly
strengthening areas of the bridge structure that are
subject to high loads.

Maintenance or restoration of corrosion protection 
and frost resistance
UHPC is an almost non-porous material that is
absolutely frost and de-icing salt resistant, even
with a very thin layer of material. UHPC is also
absolutely seawater resistant and can also be
processed underwater. Thanks to these properties,
the repair effort for exposed reinforcements is
significantly lower than for standard concrete.
Only half of the material coverage is required
compared to standard concrete

Restoring or increasing the frictional resistance of 
the concrete surface
Through the addition of ceramic or mineral additives
and their very high adhesion to the UHPC material,
any friction coefficient can be guaranteed over a very
long period.

Restoring or increasing the fire resistance of components
UHPC HT (high temperature resistant) materials are
endurance-resistant up to over 1000°C /1832°F. All UHPC
materials are extremely resistant to shock temperature loads.

Increase thermal insulation
UHPC and UHPC HT in combination with extremely
thin high-performance insulating materials can lead to
high-strength and highly insulating structures.

Permanently closing cracks with a static and sealing function
UHPC Castable are based on nanotechnology, they are
extremely thin and penetrate into the smallest pores or
cracks and seal them permanently.

www.hhbc-consulting.de
info@hhbc-consulting.de

UHPC Hot gas slide system in a cement plant

A customer from the cement industry had permanent problems with a hot gas gate valve. The gate valve was made of a stainless steel construction with a refractory heat protection lining. The average gas temperature is in the pipesystem is 800°/1472°F - 1000°C/1832°F.

The problems in detail were
  • Significant wear due to high dust loading in the gas flow
  • Heat exchange problems arose as a result of temperature changes and the result was breakdowns in the refractory lining and problems with the movement of the slide.

We engineer a slider made complete of UHPC HT (High Temperature) with the following characteristics
  • High thermal shock resistance
  • Thermal stability up to 1100°C/2012°F
  • Very high wear resistance
  • High impact resistance
  • There was no metallic reinforcement used, so there was no metallic thermal expansion
  • Due to the very high strength values ​​of the UHPC used, the board thickness could be reduced by more than 60% compared to the old refractory construction.
  • This resulted in a weight reduction of almost 50%, which also reduce power consumption.
  • a drastic reduction of the idle time and better movability of the gate valve resulted in a 16% better production.

Here are a short video to show the impact resistance of the gate plate



www.hhbc-consulting.de
info@hhbc-consulting.de


UHPC - Wear protection in cement plants

Large quantities of materials like clinker, cement,
lime and granulated slag are handled in a cement
plant. To ensure a constant production, most of
the conveying, storing and production equipment
must lined with wear protection products.

UHPC (Ultra High Performance Concrete)
wear protection systems are engineered for wet
and dry system cement plants, grinding
clinker or grinding slag plants.

Til today the most of the interantional OEMs like
Polysius, FLSmidth, Loesche, FCB, Gebr. Pfeiffer,
KHD, IKN, etc. use UHPC wear protection systems
in their machines.

There is a 25 years long experience in engineering of
UHPC wear protection systems for dynamic and static
seperator systems, clinker cooler and grinding systems,
like hammer mills, vertical roller mill, high pressure
mill and crusher.

Mill systems in which UHPC wear protection 
systems were used

FLS ATOX coal mill
FLS OK mill
Gebr. Pfeifer MPS mill
Claudius Peters EM mill
Polysius QUADROPOL mill
Polysius DOROL mill
Loesche LM mill
Christian Pfeiffer QDK separator
KHD SKS Sepmaster separator
KHD V-Separator
Polysius SEPOL separator

Standard application areas for UHPC 
wear protection systems
Cyclones  Seperator
Pneumatic transports systems

Hydraulic transport systems
Mechanical transport systems
Chutes
Chain conceyor systems
Slide gate valves
Ventilator housing
Coal, cement and clinker mills
Flash dryer system
Coal bunker
Silos
Dedusting systems


WPE DK International

Phone: 0049 176 601 73146
E-mail: info@wpe-dk.dk
Homepage: www.wpe-dk.com