What is Cor-Tuf® UHPC
Cor-Tuf® Ultra-High Performance Concrete (UHPC) is a class of concrete that is exceptionally strong and durable but is also highly workable. Originally developed by the U.S. Army Corps of Engineers, it combines form and function with strength, resiliency and the ability to be prepared and poured in mass quantities via conventional methods.
The ingredients used to manufacture Cor-Tuf® UHPC are approximately 80% the same as traditional concrete. It is what goes into the remaining 20% that makes Cor-Tuf® UHPC unique and innovative. Many of the component ingredients are either derived from recycled materials themselves. Additionally, much of the heat energy necessary for our cement kilns is provided by the crumb rubber created in the same tire recycling process.
Using pre-stressed solutions, integrated fibers are added to the concrete mix. The fibers vary from polyester to fiberglass bar, basalt, steel, and stainless steel. Each of these integrated fibers create a progressively stronger end product, with steel and stainless steel delivering the greatest gains in strength.
Cor-Tuf® UHPC has 10 times the compression strength of traditional concrete. Additional mix techniques can be applied to achieve 50,000 psi or higher.
Our team of experts arrives on-site and mixes Cor-Tuf® UHPC in real-time to ensure you get the highest quality of this new concrete technology. Strict quality control measures are followed to ensure the excellence of the final product.
Cor-Tuf® UHPC initially hardens in two to three hours and can be handled in about eight hours following a pour. The cure time varies with temperature and humidity, but generally produces half-strength in five to seven days. Full curing in 28 days. Additional strength can be achieved with the use of supplemental techniques such as the use of increased temperature, steam, or both during curing.
The much higher strength of Cor-Tuf® UHPC (easily ten times plus that of ordinary concrete) enables architects, engineers and design components of buildings and infrastructure to be significantly smaller and lighter, using less basic material. Furthermore, smaller and lighter translates to lower energy usage in building and transportation of huge portions of our built environment.
Benefits of Cor-Tuf® UHPC
- Longer useful life (estimated longevity exceeding 75 years versus 15-25 years for traditional concrete)
- Aggressive environmental resistance (impervious to water)
- Lighter weight (Concrete wall panels designed with UHPC are 25% to 33% thinner, requiring less material and footing requirements)
- Impact resistant
- Dimensional stability
- Freeze/thaw resistant
- Moisture resistant
- Chemical resistant
- Reduced maintenance
Cost-savings with Cor-Tuf® UHPC
Cost savings is another benefit of Cor-Tuf® UHPC. While Cor-Tuf® UHPC requires a larger upfront cost when compared to traditional concrete, this new concrete technology delivers a much lower life-cycle cost. Less material is required for construction projects, resulting in a lower gross weight. This reduces the size and complexity of footing and support requirements. Over 80% of the materials in Cor-Tuf® UHPC are the same as those used in ordinary concrete so no massive retooling of current industrial infrastructure is necessary. Further, the remaining 20% is either directly recycled or material which was entirely seen as a waste from other industrial process.
Construction can be completed more quickly with prefabricated UHPC elements, delivering cost savings in several areas of construction. The extended longevity of Cor-Tuf® UHPC virtually eliminates maintenance costs and drastically extends the life of the product. When the cost of Cor-Tuf® UHPC is spread out across the life of the product, it has extensive cost benefits over standard concrete.
UHPC has demonstrated a durability and resistance to natural forces not seen in previous concrete products. A study of untreated UHPCs (similar to Cor-Tuf) were conducted by the University of New Brunswick, Canada. The samples were placed at the mid-tide level of a marine exposure site 1995. The results showed the samples were impervious to water, had negligible surface damage, and had resisted 12 years (now more than 20 years) of more than 1,000 freeze/thaw cycles and storms.
U.S. Federal Government Recommended
The U.S. Federal Government and many state governments are strongly recommending that UHPCC be used in a variety of highway infrastructure projects, ranging from accelerated bridge construction, bridge repair and maintenance, precast concrete deck panels, and field-cast connections between prefabricated bridge components.
The U.S. Department of Transportation Federal Highway Administration (FHWA) also advocates the use of UHPC through its Every Day Counts (EDC) program. EDC identifies and utilizes innovative technologies to reduce project timelines, increase safety, reduce traffic delays, and lessen the environmental impact of construction at the state and local levels.
Every two years, the FHWA works with state and local transportation departments, governments, and other vested parties to identify the latest innovations to support. The EDC-3 Innovations for 2015-2016 and the EDC-4 Innovations for 2017-2018 include the use of UHPC connections for prefabricated bridge elements and systems (PBES), making it a favored concrete technology for these applications.
UHPC Construction Insights
Global UHPC market size by application, 2018 (%)