UHPC Phalt Halbstarrer Deckschichtbelag für Kreisverkehre

Wir haben in diesem Jahr bis dato UHPC Phalt halbstarre Deckschichtbeläge für drei Kreisverkehre produziert und geliefern. Je Kreisverkehr wurden zwischen 600 und 1000 m² halbstarre Deckschicht installiert.

UHPC Phalt ist eine Kombination aus einer Asphaltschicht in deren Struktur (Matrix) die Hohlräume mit UHPC Phalt Mörtel vergossen wird. UHPC Phalt Mörtel erreichen extreme Festigkeitswerte, die weit über denen von Standardbeton liegen.

UHPC Phalt kann auf fast allen neuen oder vorhandenen Untergründen verlegt werden.

Auszug aus dem Leistungsverzeichnis:

Halbstarre Deckschicht aus einem hohlraumreichen Traggerüst aus Asphaltmischgut 0/11 oder 0/16 und einem

Hochleistungsverfüllmörtel in zwei Arbeitsgängen nach Unterlagen des Auftraggebers herstellen. Fugen der Unterlage übernehmen.

Asphalttraggerüst ohne Verwendung von Asphaltgranulat. Hohlraumgehalt des Asphalttraggerüstes mindestens 25 Vol.-v.H. Grobe Gesteinskörnung Kategorie SZ18.

Kornform Kategorie SI15. Hohlräume des Asphalttraggerüstes mit Hochleistungsverfüllmörtel mit Größtkorn von höchstens 0,25 mm.

Volumenänderung im Festmörtel höchstens 1,0 Vol.-v.H.

Biegezugfestigkeit nach 3 Tagen mindestens 10 MPa.

Biegezugfestigkeit nach 28 Tagen mindestens 12 MPa.

Druckfestigkeit nach 3 Tagen mindestens 65 MPa.

Druckfestigkeit nach 28 Tagen mindestens 100 MPa.

Die gute Nachricht für unsere Kunden ist, das wir die Materialpreise von unseren UHPC Phalt Produkten aus diesem Jahr auch für das kommende Jahr 2024 problemlos halten können.

UHPC Earthquake security systems for existing buildings

Ultra High Performance Concrete (UHPC) is a high-strength, ductile material formulated by combining cement, microsilica, fine sand, water, and steel or ceramic fibers and mesh.

The UHPC concrete provides compressive strengths up to 250 MPa / 36200 psi and flexural strengths up to 30 MPa / 4300 psi.

The ductile behavior of UHPC is, with the capacity to deform and support flexural and tensile loads, even after initial cracking. 

 

Façade elements made by UHPC, protect people and vehicles in an earthquake against fragments litter in building structures made 
of concrete and brickwork.

Concrete ceilings are rigid and brittle structures that at the an earthquake stress the concrete structure can break partially. The fracture is not 
a slow phenomenon under load - the fracture occurs when overloading on suddenly.

The result is that to loosen individual fragments of the ceiling could (fragments litter) fall on machines or people. Are the fragments large enough, it can lead to complete component failure.

UHPC prefabricated ceiling structures prevent like a prestressed network the fragments become loose during the quake from the ceiling.

People and machines are protected by such a suspended ceiling construction.

Emergency exits can win with such additional structure several times of safety.

Just as concrete ceilings and concrete columns are complex constructions an essential safety feature of a quake. The concrete columns must take tremendous 
flexural and compressive forces. A chipping of the concrete structure of the inner steel reinforcement would have a very rapid component failure result.

Concrete columns can by a jacket (by shedding) of UHPC gain much stability and carrying capacity. A chipping of the concrete structure at a load by an earthquake of small and medium thickness is almost impossible with the appropriate cover. 

Advantages of UHPC

• Extreme high compressive strength
• High flexural strength
• Extreme low porosity
• Extreme good flowability
• Fast increase of compressive strength (min. 70% after 48 hours)
• High wear and impact resistance
• Absolute frost and thaw resistance
• Impermeable to fluids but still vapour permeable
• Anticorrosive features
• Good bonding to sub-bases, aggregates and reinforcement
• High temperature resistant
• Jointless lining
• Usable as mortar, grout and spray
• High ductility in combination with fibres or nano fibres
• Usable with standard concrete tools
  
  

UHPC - His entry before and after a quake

UHPC materials can be used as additional safety in new concrete structures such as buildings, bridges, etc. For existing buildings and very old buildings, targeted activities involving the use of UHPC materials can significantly increase the safety of people and buildings. With UHPC materials, damaged buildings can be repaired to restore their old stability or improve their stability against earthquake loads by improving their building structure.

Possible applications for high quality UHPC materials

Repairing

To make existing structures safer for future earthquake

Retrofitting

To upgrade the earthquake resistance up to a level of  the present day codes by appropriate techniques

Strengthening

To upgrade the seismic resistance of the a damage building

Rehabilitation

Reconstruction or renewal of a damaged building to provide the same level of function, which the building had prior to the damage

Restauration

Rehabilitation of buildings in a certain area

Remoulding

Reconstruction or renewal of any part of an existing building owning to change of usage or occupancy

Example of retrofitting techniques

• Minor cracks
  Repair by injecting UHPC
• Buckled longitudinal reinforcement, broken ties and crushed concrete
  Replacement of new reinforcement welded with existing bars and new additionally closed ties were placed, UHPC concrete with low shrinkage properties installed.
• Severely damaged columns adjacent to added walls
  Retrofitting with encasing in UHPC concrete with appropriate longitudinal and transfers reinforcement.
• Other columns
  Retrofitted with wire mesh and cover with 50 mm UHPC concrete by spraying or casting
• Existing masonry walls
  Are retrofitting by using wire mesh and 30 mm of UHPC® mortar or spray

Like concrete cover constructions, concrete columns are also essential safety aspect in a quake. The supports have enormous bending and compression forces to take. 
A spalling of the concrete structure from the internal steel reinforcement would have a very fast component failure result.

As with the concrete floors, columns can be replaced by a grouting UHPC gain significantly in stability and carrying capacity. A flaking of the concrete construction is under load from a quake of small and medium strength with 
appropriate sheath almost impossible.

In a quake will be in the brickwork of a building very quickly showing cracks in the in the worst case, individual stones break loose (Rubble throw) or a whole bandage, which too can lead to a component failure. The cracks in the masonry after a quake are permanent and can become one uninhabitability and demolition of 
the building to lead.

Damaged masonry will be repaired differently depending on the degree of damage.

Fine cracks can be filled with UHPC injection methods. Loose masonry, bad mortar can be increased by new masonry and UHPC mortar substantially in the strength and bending tensile strength. Masonry can also be improved in its entire surface with a fibre reinforced UHPC layer in combination with steel or fibreglass reinforcement substantially in its static structure. Especially glass fibre or carbon fibre reinforced 
UHPC show a high ductility.

In any case, should structural modifications such as those described here, be agreed in consultation with 
an architect, stress analysts and the competent local planning authority.