Recycling of UHPC concrete compared to standard concrete

Our UHPC concretes are far superior to standard concretes in all technical properties and actually
make them a competitive material for steel. Also in this comparison, UHPC concretes have advantages such as corrosion resistance and temperature resistance, etc.

UHPC concrete constructions achieve a multiple service life of standard concrete in comparable constructions. This means standard concrete structures are demolished much faster and the debris has to be recycled. The demolition material is used as gravel. It is currently trying to recycle this demolition material as a building material.

In addition to a longer service life compared to standard concrete, UHPC also has many advantages here.

1. UHPC concrete has a very high compressive strength which is similar or better to many standard aggregates of standard concrete.

2. UHPC concrete granules have no to extremely low porosity. Thus, UHPC Granules does not absorb very little water.

4. UHPC concrete granules are corrosion and seawater resistant. UHPC concrete granules can be easily processed with standard concrete or UHPC concrete.

6. At the moment we are working on trying to prepare standard concrete material granulate, so that it can be used as a fine aggregate for some UHPC grades.

7. We also plan to use recycled UHPC high temperature material. It could very well be used as aggregate for UHPC HT or for refractory materials.

Fast - Faster - UHPC Rapid for new installation and repair

For very fast assembly in the taxiway of an airport
we have delivered a special UHPC (Ultra high
Performance Concrete) Cast.

Last Airport project:
There had to be laid cable protection pipes in the
area of ​​the taxiway. For this purpose, a slot of
20cm / 7,87in wide, 100cm / 39,37in deep and
100meters /109yd long in the existing concrete
floor had to be milled. For the filling of the slot
after the cable protection pipes had been laid,
we delivered a quick-hardening UHPC Rapid
Cast. The setting time of this special UHPC
is 2-3 hours, depending on the environmental
conditions. After this time it reaches a strength
above 20 MPa / 2900 psi. The final strength
after 48 hours is about 80 - 100 MPa /
1160 - 14500 psi.


Originally the UHPC Rapid product series
was developed about 20 years ago for wear
protection repairs in steel plants, power plants,
mining plants and cement plants.
Later, the UHPC Rapid was used not only as
a mortar but also as a cast and shotcrete. The
UHPC Rapid shotcrete was particularly used
in mining tunnels and the UHPC Rapid Cast
was used in the new lining and repair of
roadways, roads, storage areas and industrial
floors.

Meanwhile, it is also used as repair material
in airports, on highways and bridges.

New construction and repair of Jetties with UHPC concrete

For modern jetty constructions, UHPC concrete

offers many advantages compared to standard

concrete, steel or wooden constructions.

- All jetty elements can be prefabricated or cast
   on site in a short time.
- UHPC concrete has no or only extremely low
   pore volume and is thus absolutely seawater
   and corrosion resistant.
- UHPC concrete hardens under water. It can
   therefore be processed in and under water.
- UHPC concrete has a standard strength
   between 120 MPa/17400 psi and
   250 MPa/36250 psi.
- UHPC prefabricated elements can be made
   considerably thinner due to the very high
   strength and the absence of porosity, and
   thus with significantly less weight.

Due to the properties of UHPC concrete listed
above, such constructions do not require further
inspection. It can be assumed that the service
life is almost 100+ years.

Since UHPC concrete has very good wear and
impact resistance, harsh harbor conditions and
extreme environmental conditions such as ice
are no problem.

Installation

UHPC concrete can be produced by us as mortar,
casting compound or shotcrete mass. For processing,
a compulsory or pan pot mixer is needed. Our
shotcrete and castable UHPC material can also be
pumped over longer distances.

Repairs of damaged standard concrete, steel or 
wooden constructions

Jetties can be severely damaged by impact, corrosion,
rotting or faulty concrete processing. The repair
with UHPC concrete is simple and requires little
effort.

For preparation, remove any loose particles and
buildup such as clams, algae and the like.
A mold should be installed around the columns.
The water does not have to be removed from the mold.
The UHPC concrete is poured directly in the water.
The concrete displaces the seawater from the mold.
The mold can be removed after less than 48 hours.

This type of repair has been used for more than 20
years as a standard repair method on offshore platforms.

UHPC Shotcrete system - more than 20 years in use

For large areas that are to be lined in a short time, 
UHPC Shotcrete is here a very good solution. 
UHPC Ultra High Performance Concrete qualities 
easily achieve minimum 120 MPa/1750 psi 
compressive strength.

UHPC Shotcrete material must be mixed before 
actually spraying. It is importance for the quality of 
UHPC Shotcrete that the amount of water is kept 
very precisely. Too much water reduces the material 
quality to a decisive extent. UHPC Shotcrete is using
a water/cement ratio of 0,2.
Our UHPC Shotcrete binders have a continuous 
temperature resistance up to 450°C/850°F. For 
temperatures over 450°C/850°F up to 
max. 1200°C/2200°F, we produce a UHPC HT High 
Temperature binder. The processing of the UHPC HT
version is carried out in the same way as with 
the normal temperature versions.

 

Characteristics of UHPC Shotcrete

 - No dust development, better working conditions
 - Due to the very high strength values, material
   layer thicknesses can be reduced
 - As with all other UHPC grades, a water
    impermeability is achieved from a layer
    thickness of 10 mm.
 - UHPC spray is very resistant to any corrosion
    attac
 - More constant concrete quality due to pre-
   defined water/cement content
 - Higher compressive strength with no
   fluctuations

 - Fast uniform strength development
 - Larger layer thickness due to more effective
   reaction of the additives
 - Low material rebound (below 2%)
 - Extrem good adhesion
 - Significantly larger spray performance
 - Minimal air consumption
 - Easy use of fibres
 - High security

UHPC Shotcrete in the new construction of tunnels or canals
Especially for tunnel construction, the use of UHPC
Shotcrete is an advantage. There is no need for high air
pressures like a standard shotcrete, UHPC Shotcrete is
self-compacting, the adhesive properties are extremely
good, so there is extremely little rebound and material loss.

A possible desired reworking of the surface is easily
possible without any effort. The material dust development during injection is extremely low.

UHPC shotcrete as repair material for existing tunnels or canals
Whether large or small tunnels and channel geometries whether concrete, steel or corrugated metal constructions can be repaired quickly, permanently and cost-efficiently.
Due to the fast development of strength, even larger repairs can be carried out quickly and efficiently with little machine outlay.
Due to the extremely good adhesion and corrosion resistance,
elaborate preparation is not necessary. With a simple high
pressure cleaning device, the loose particles should be
removed and then UHPC Shotcrete material can be installed.
Machines and material for minor repairs can be transported
without a problem with a normal pick-up vehicle.

 

WPE DK International

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