UHPC is a ductile cementitious composite material with significantly better properties than traditional concrete
Compressive strength: 120 to 200 MPa
Tensile strength: 7 to 15 MPa
Air and watertight – no damage from chlorides, freezing/thawing or carbonatation
Resistant to alkali aggregate reaction (AAR)
High resistance to chemical attack
High abrasion and impact resistance
The exceptional composite performance of UHPC is due to its composition.
The optimization of the cementitious matrix reduces its permeability and porosities.
A very low W/C ratio (~0.2) and an efficient admixture allow the proper workability during the installation .
The metal fibers provide tensile strength and ductility of the material. Depending on the UHPC application, between 200 and 300 kg/m3 are required.
UHPC was developed in the 1990s. Initially a laboratory material, it has become an indispensable construction material over the past few years.
UHPC was used for the first time in Switzerland to build a bridge in 2003. In 2014, the Chillon Viaduct was reinforced with a UHPC overlay ( over 2,000 m3) This project increased the interest in using UHPC for bridge rehabilitation and preservation.
The following website lists all deployed UHPC projects in Switzerland: uhpfrc-map
In Switzerland, the SIA 2052 technical specification (published in 2016) classifies UHPC in 3 categories (U0, UA and UB) depending on their tensile strength.
In France, the standards NF P 18-451 / 470 and 710 govern the use of UHPC in structures and specify design regulations for UHPC.
Interest in this material is growing and many countries around the world are developing similar design guides for UHPC.
A thin layer of UHPC is sufficient to reinforce a bridge deck or building slab. The strength of the cross-section changes completely with the addition of UHPC in the top layer and the rise of the neutral axis.
In addition, this reinforcement layer provides long-lasting protection against external elements such as chlorides.
From 25 mm upwards, UHPC is considered to be watertight . A single layer applied to a new or existing structure provides long-term durability protection. With a service life far longer than that of traditional concrete and other conventional waterproofing materials, the use of UHPC reduces significantly on-going maintenance costs. UHPC is highly resistant to abrasion and does not require an additional protective layer.
The waterproofing and abrasion resistance of UHPC allows existing structures to be protected against all external attacks such as water, chlorides, chemicals, and abrasion,
The protection can be installed on horizontal or vertical walls. It can also be shotecreted.
The change of use of a building often requires slab reinforcements. A thin layer of UHPC can improve the load-bearing capacity of the slabs while limiting the amount of dead weight. Localized reinforcement may also be required to improve punching resistance.
The architectural or time requirements of a project often require the use of prefabricated elements.
UHPC can be used to create new innovative shapes and make structures lighter. Prefabrication can be carried out in the plat or directly on site.
Difficulty of access or complex geometries make the construction of certain formworks very expensive. The projection of UHPC using shotcrete construction methods makes it possible to overcome these constraints and provides reinforcement and waterproofing for all surfaces.
Dams and locks are exposed to water and ships throughout their entire life. Continued abrasion significantly reduces concrete rebar cover leading to corrosion and loss of structural strength. Construction and retrofitting with field cast or shotcrete UHPC provides high durability against abrasion and high strength against ship impacts.
Traditional concrete materials fail to possess both physical strength and chemical durability when applied to marine structures as chlorides can penetrate the concrete and cause damage to the steel reinforcement. UHPC's unique impermeable properties against chlorides make it an ideal solution to prevent future rebar corrosion and future maintenance of existing marine structures. This helps to achieve structural integrity in the long-term.
Whether you're building new or rehabilitating existing runways or apexes, UHPC extends the service life and decreases the need for recurring maintenance. The use of UHPC helps improve wear resistance, bearing capacity, and increased the life-cycle while reducing the project completion time.
Whether it's the preservation of parking garage decks or the retrofitting of inverted tee beams, the properties of UHPC make it an innovative, durable, and effective solution to extend the life of parking structures.
Treatment plants require innovative concrete technology to fight against abrasion, acids, sulfates, and carbonation. Due to its impermeability, UHPC increases the durability and lifespan of treatment structures.
Many of our bridges are in need of significant repair, including railway structures. UHPC is ideal to strengthen and provide corrosion protection for aging railway bridges including beams, piers, and abutments. Deteriorated railway ties can be replaced with field cast UHPC to increase the longevity of the railway.
Industrial floors are oftentimes exposed to harsh environments and impacts. UHPC is a supreme material due to its chemical resistance and low permeability. Both its chemical and physical resistance are ideal for a variety of industrial flooring projects.