UHPC Protections

LBM UHPC offers extrodinary protections that lead to massive cost savings.

Corrosion Protection

Corrosion is a natural process, which converts a refined metal to a more stable form, such as its oxide, hydroxide, or sulfide. It is the gradual destruction of materials (usual metals) by chemical and/or electrochemical reactions with their environment(s).

Reinforced concrete plays an important role in the corrosion of the reinforcement and the protection offered by the concrete to the reinforcement (passive corrosion protection). As the reinforcement begins to corrode, the associated increase in volume can cause the concrete to chip around the corroding reinforcement. As corrosion progresses, loss of substance at the reinforcement can jeopardize the load-bearing capacity of the structure.

The reinforcement in reinforced concrete is protected from corrosion by the high alkalinity of the pore water with pH values ​​between 12.5 and 13.5, since at such pH values ​​on the steel surface a passive layer forms (passive corrosion protection), which makes the anodic iron dissolution practically in derogation. The passive corrosion protection can be lost by carbonation or chloride action.

Repair principles

Preventing the anodic sub-process
One possibility is to restore the alkaline environment and thus the passive corrosion protection in the vicinity of the reinforcement by applying a UHPC mortar (passivation or realkalisation).

Preventing the electrolytic sub-process
By lowering the water content in the concrete, the corrosion rate can be reduced to practically negligible levels, since all described transport processes are inhibited in the concrete. For this purpose, the penetration of water from the outside is prevented by means of suitable surface protection systems. In addition, it must also be prevented that water vapor from the inside or soil moisture penetrates into the component.

Cost example

The costs for cathodic corrosion protection for concrete bridges can be calculated with approx. 3-7% of the new building price.

LBM UHPC is a special material with a minimum compressive strength of 120 MPa and a water/cement ratio of less than 0,2. LBM UHPC products can be used for the rehabilitation of concrete and steel structures. In addition to the normal cleaning of the rehabilitated surfaces, no further special cleaning work is necessary. LBM UHPC products can rehabilitate construction next to the corrosion protection even with the admixture of ceramic aggregates to increase the static bearing capacity. UHPC is absolutely saltwater resistant.

Standard corrosion protection methods are:

• Plating, Painting, Antifouling
• Cathodic Protection
• Sacrificial Anode System
• Impressed Current Foreign Anode
• Hot Dip Galvanization

Benefits of UHPC anti-corrosion system:

  •     Easy installation as Spray, Mortar, Cast-in-place

  •     Usable at very high humidity

  •     Extremely high impact strength

  •     Extremely high resistance to mechanical loads

  •     No pore formation

  •     Maritime and port water resistant

  •     Installation in the water is possible

  •     Duration resistant

  •     The standard drying time is under 12 hours

  •     Penetrates into the smallest joints and cracks, and closes them permanently

  •     Jointless installation

  •     Very good thermal shock resistance

  •     Can be used up to 400°C/752°F without problems

Wear Protection

LBM UHPC is high wear resistance and ultra-dense concrete system. UHPC is a material mix of cement, micro silica, superplasticizers, and ceramic aggregates (Quarz, Bauxite, Corundum, and Silicon carbide). The combination of high compressive strength, high-density particle packing, and extremely hard aggregates, creates a flexible and simple-to-install wear-resistant material.

Such UHPC material can install in any thickness it is needed. It is a jointless lining and over-head installation is not a problem. It is produced in a mortar and in a castable material version. For the installation of such wear protection system, it is necessary to install an anchor system. As a standard we recommend the following anchor/reinforcement system:

a) Rhombic wire mesh
b) Honey- or Hexagon mesh

We produce our LBM UHPC in standard quality with a long-term temperature resistance of max. 450°C/842°F and in a high-temperature quality with a long-term temperature resistance of max. 1200°C/2192°F. All our UHPC material qualities are mixed according to the same system. For mixing a pan pot or shaft mixer is required. UHPC has been used worldwide for more than 25 years. These types of UHPC materials have been successfully used in the steel, cement, power, transportation, marine, and mining industries.

Advantages:

  •     Wear-resistance

  •     Impact resistance

  •     Corrosion resistance

  •     Flexible in layer thickness

  •     Overhead installation is possible

  •     Thermo shock resistant

  •     Jointless lining

Earthquake

LBM UHPC can be used to prevent and repair earthquake damage. Fibre-reinforced Ultra-High-Performance Concrete is a high strength, ductile material. The material provides compressive strengths up to 220 MPa and flexural strengths up to 30 MPa. The ductile behaviour of this material with the ability to deform and support bending and tensile loads even after initial cracking is exceptional and not comparable to standard concrete.

Advantages of UHPC:

  • Extremely high compressive strength
  • High flexural strength
  • Extremely low porosity
  • Extremely 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
  • Great 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 nanofibres
  • Usable with standard concrete tools

Identification of damage in a reinforced concrete building:

  • Soft storey failure
  • Floating columns
  • Plan and Mass irregularity
  • Poor quality of construction materials and corrosion of reinforcement

LBM 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 while adding to the longevity of the lifespan of the structure. With LBM 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 UHPC materials:

Repairing

To make existing structures safer for future earthquakes

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 a damaged or older structure

Rehabilitation
Reconstruction or renewal of a damaged structure to provide the same level of function, that the structure had prior to the damage

Restoration
Rehabilitation of structures in a certain area

Remoulding
Reconstruction or renewal of any part of an existing structure owning to change of usage or occupancy.

Like concrete cover constructions, concrete columns are also an 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 grouting UHPC gain significantly in stability and carrying capacity. Flaking of the concrete construction is under load from a quake of small and medium strength with appropriate sheath almost impossible.

A quake will be in the brickwork of a building very quickly showing cracks 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 uninhabitable and demolition of the building is required. Damaged masonry will be repaired differently depending on the degree of damage.

Fine cracks can be filled with UHPC injection methods. Loose masonry and bad mortar can be increased by new masonry and UHPC 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 shows a high ductility.

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

We are ready to assist you in the local approval process and to the extent, we are able to provide the required documents.

"It is only impossible if you have not tried it"

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