LBM UHPC offers Architects and Designers a new world to let ideas become reality.
For more than thirty years UHPC (Ultra High Performance Concrete) has been used worldwide in hundreds of industrial sectors. In the construction industry, over the past 15 years, more and more people have recognized the many possible applications and technical advantages of UHPC.
Today UHPC faces three main problems:
1. There is no universally accepted technical definition of UHPC internationally.
2. There is no technically accepted material standard for UHPC.
3. Cement is a single material and UHPC is a mixed material.
Today, simple cement is only used to a very limited extent in the construction industry. A large number of additives are used worldwide to meet the requirements of the construction site/installation. These additives are added either to produce the specified concrete in a local mixing plant or on-site.
Chemical additives for modifying standard concrete properties:
Accelerator for solidification or hardening
LBM UHPC already possesses a multitude of properties without the addition of additives.
LBM UHPC is manufactured exactly according to the requirements of the respective project. This ensures a very high consistent quality.
Precast and Tilt-up elements made by LBM UHPC
LBM UHPC Ultra-High-Performance Concrete offers architects and designers today a variety of novel design options, especially in the manufacturing of precast concrete elements. The difference in the production of LBM UHPC and standard concrete elements can be described as follows.
LBM UHPC Compressive strength: 100 MPa/14500 psi to 250 MPa/36260 psi
Standard concrete compressive strength: 10 MPa/1450 psi to 80 MPa/11600 psi
LBM UHPC Flexural strength: 11 MPa/1595 psi to 30 MPa/4350 psi
Standard Concrete flexural strength: 1 MPa/145 psi to 5 MPa/725 psi
The distance between steel reinforcement and the concrete surface can be chosen very low since LBM UHPC materials using aggregate with a grain size from 0 – 3 mm LBM UHPC materials have extremely little to no porosity.
In order to prevent corrosion of the reinforcement, a large cover must be selected by standard concrete.
LBM UHPC materials achieve their strength without the use of gravel. The grain size of the aggregate is much lower than standard concrete. The distances between the reinforcing bars can be chosen to be much lower without the danger of voids being created during casting.
Standard concrete requires a gravel surcharge. Due to the grain size of the gravel, the reinforcing bars must be laid at a minimum distance.
The adhesion between LBM UHPC materials and steel is several times higher than that of standard concretes due to the almost 100% wetting of the steel surface.
Due to the high compressive strength of LBM UHPC, prestressed elements can be given a higher prestressed force or the component geometry can be made smaller.
LBM UHPC Materials reach 70% of their nominal strength after less than 48 hours. This makes it possible to remove the elements much faster from the form.
LBM UHPC elements can take on higher forces than standard concretes with low geometry.
Properties of LBM UHPC:
– High resistance to mechanical loads
– Density surface
– No pore formation
– Maritime and port water resistant
– Duration resistant
– The standard drying time is under 48 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
– High compressive strength
– Extremely fast development of compressive strength
– High wear and impact resistance
– Absolute frost and thaw resistance
– Impermeable to fluids but still vapor permeable
– Extremely good fluidity
Bridge deck elements
Tilt-up constructions elements:
LBM UHPC is very well suited for the production of tilt-up elements on site. Due to the extremely high strength values of LBM UHPC, very large and expensive elements can be cast quickly. Since LBM UHPC has a very fast strength development (about 70% of the rated strength after less than 48 hours), a much faster and safer installation is possible compared to standard concrete elements. Similarly, much finer and more filigree design surfaces compared to standard concrete are possible.
Sound insulation and security walls:
LBM UHPC concrete is extremely well-suited for the production of sound insulation and safety precast elements. In their function, LBM UHPC elements are much more effective, lighter in weight, permanently resistant to all environmental influences, highly corrosion-resistant, and have an average life expectancy of more than 100 years.
Especially with LBM UHPC, it is now possible to process all kinds of recycling aggregates like rubber, glass, concrete, plastic, etc.
LBM UHPC gives the architect an incredible array of design options, from elegant, intricate surfaces and geometries to extremely resistant security walls to secure highways against possible traffic accidents and safeguard against terrorist attacks.
LBM UHPC offers solutions to solve even the most complex building design. On the tightest of lots or wide open acreage, short schedules or long-term projects. LBM UHPC can work with you to develop a cost effective UHPC solution to meet your exact requirements.
Using LBM UHPC precast concrete products today is the solution of choice for architects, engineers, developers, and owners who have been quick to recognize the many inherent qualities of LBM UHPC products.
LBM UHPC is capable of providing a wide range of finishes including brick face, decorative exposed aggregate, sandblasted and other decorative finishes. We are responsive to the designer’s creative needs, making it cost effective to use complex shapes and configurations. The smooth surfaces produced with precast LBM UHPC concrete and ability precast, pre-stressed concrete to span long distances makes precast ideal for use in manufacturing and storage structures. Additional applications for LBM UHPC precast include piles and deck for railroad and highway bridges, railway cross-ties, burial vaults, educational institutions, commercial buildings, public buildings, hospitals, libraries, and airport terminals.
LBM UHPC is the ideal replacement for standard concrete in just about any and all applications. LBM UHPC is particularly beneficial in the following applications of traditional concrete:
- Precast pouring of larger and longer structural elements
- Injection or extrusion techniques (molding)
- Pre and post-tension components
- Precast internal and external beams
- Precast cladding or curtain walls
- Load-bearing wall units
- Shear walls
- Cross-wall systems
- Longitudinal wall systems
- Unique shaped structural elements
- Precast edge, internal, and corner columns
- Hardened Façades
- Hollow-core slabs
- Cast-in-place joints between precast beams
- Precast deck panels
- Cast-in-place joints and stud pockets of precast deck panels
- Link slabs between adjacent spans
- Precast parapets and side barriers
- Precast inlets for storm water management
- Tilt-up construction
Benefits of LBM UHPC precast:
- Increased energy efficiency
- Increased durability
- Minimal to no maintenance
- Diversity in design expression
- Repetitive pre-casting (faster production time)
- Consistent high levels of quality control
- Variety of finishes on load-bearing and non-load bearing components
- Architects can design thinner concrete elements, improving the architectural appearance of their work.
- High modulus of elasticity (MOE) which can be in the 7,500 ksi range
- High tensile strength compared to normal concrete
- LBM UHPC has a higher bond strength to steel reducing the size of a concrete placement needed to bond concrete elements.
- Structural elements can be smaller and more lightweight compared to those made with normal concrete
- LBM UHPC eliminates capillary pores making it impervious to water and salt penetration without sealing the surface.
- Extremely low shrinkage making it perfect for non-shrink grout
- LBM UHPC transfers even the finest relief from molded surfaces resulting in more ideal architectural concrete pieces.
Some of the more innovative ways this new concrete technique is being applied include:
- Construction of thinner sections for complex structural forms
- Potential elimination of primary and/or secondary reinforcement
- Off-site manufacturing
- Accelerated Bridge Construction (ABC) – UHPC is ideal for the durable field-cast connections required in ABC.
- Retrofit and modification projects – UHPC’s adhesive quality makes it ideal for repair and retrofitting of many structures, such as parking garage decks, spalled structural members, and building columns and walls.
- Architectural design – UHPC allows for the precise replication of architectural details. It can be casted or molded to match any desired appearance, including masonry, wood siding, board & batted, and textured concrete. Period-specific designs and demands for surface texture, color, and shape are now possible.
- Structures exposed to harsh elements – Structures such as pier foundations and bridges built over water that have foundations repeatedly exposed to saltwater and moisture are ideal candidates for UHPC, given its moisture and chemical resistance and impervious to freeze and thaw cycles.