Concrete construction firms are seeing more projects using Ultra High Performance Concrete (UHPC). Everything from bridge decks to building repairs is leveraging its unique strength and durability properties, from Federal mega-projects to municipal road repairs. Contractors must be increasingly savvy about UHPC construction to win bids and execute projects.

Fortunately, there are a lot of good references. One example is this is the UHPC checklist from the Federal Highway Administration (FHWA). Due to the agency’s involvement in the advancement and piloting of UHPC, FHWA guidelines apply to Cor-Tuf UHPC. Cor-Tuf has direct experience with FHWA standards and exceeds their requirements.

Understanding what to expect from UHPC throughout a project’s lifecycle is important. Cor-Tuf UHPC is a lot like regular concrete–we can even use ready-mix trucks and traditional concrete installation procedures here at Cor-Tuf. However, there are still some differences to be aware of.

Project Lifecycle–What to Expect with UHPC

From the project award to the final payment, you can confidently go into a UHPC bid. Let’s walk through the project phases and learn what you should know when using UHPC.

Pre-Award

• Supplier Credentials – The UHPC material supplier typically needs the requisite experience and qualifications. A reputable vendor such as Cor-Tuf can provide the required credentials and project experience (at a competitive price) that many typical concrete plants don’t have. Ensure you engage with an experienced UHPC team before getting into the weeds.
  
  
• Material Specifications – UHPC materials must meet project specifications for strength, durability, and flexibility. By definition, UHPC meets certain compressive strength requirements, but your UHPC partner should also meet the precise durability, flexural, and curing demands of the use case and conditions for your projects. Laboratory test results demonstrating the specific performance of UHPC products, including fibers, are obtained from certified ASTM C1856 labs. Your supplier should have these ready and have a reliable testing program that keeps certifications up to date. 
  
  
• Contractor Credentials – Experience in similar projects will typically be required for general contractors and subcontractors to qualify for (and win) competitive bids. UHPC vendors and their personnel may also need to go through an approval process later in the project. Bids may need to be compiled before confirming suppliers, but proactive outreach to UHPC vendors can help ensure your procurement and installation assumptions align with your crew’s prior experience in other concrete projects. 
  
  
• Budget – Of course, profit-making after winning a bid is linked to the underlying costs. Your UHPC supplier may not be selected yet, but you will ultimately want competitive pricing without upending all of your bid assumptions. All UHPC products are not created equal – some will require a lot of specialty equipment and extra costs, while others will allow you to use the same ready-mix trucks you deal with daily. Get ahead of these discussions if you can. 

With these checked off, you’ll be in good shape to move to contracting.

Pre-Construction

• Scheduling – If you’re just beginning to work with UHPC projects, it may be daunting to commit to a schedule. However, UHPC procurement, installation, and finishing timelines should not differ much from traditional concrete. Project specifications should help determine any extended curing or testing timelines. Ensure that any special personnel or inspections are accounted for in the schedule. 
  
  
• Drawings & Specifications – Designs and fabrication drawings for UHPC may differ from those for traditional concrete due to superior flexural strength and other properties. For example, the fibers used within a particular UHPC mix may make rebar unnecessary or spaced differently.  
  
  
• QA/QC Plan – Some procedures for sequencing, equipment, storage, and handling can be unique to specific brands of UHPC, but you should choose a vendor that doesn’t add a litany of specialty costs. At Cor-Tuf, we’ve developed contractor-friendly mix packages that allow you to use your sand, cement, equipment, and labor. We can support you with visits to your yard and provide batch assistance without breaking the bank. 
  
  
• Testing Plan – Some contracts require a prototype to ensure the UHPC mix will meet project-specific specifications, while others may only require an adequate test plan. Regardless, UHPC requires a similar but different testing regime from that of typical concrete, and contractors should be aware of this. ASTM C1856 is a specific testing standard for UHPC that includes cylinder compressive strength and slump testing.

Once your plans are in place, it’s time to mobilize and get out to the site.

Project Execution

• IFC Package – Updates from the supplier, engineer, crew, or project owner might make their way into the final plans based on pre-construction submittals. Consultation with your UHPC vendor will ensure that the final material quantities (premix, fiber reinforcement, admixtures, moisture, etc.) are accurate. All parties should communicate proactively and consistently to align design considerations with batching and transportation plans.
  
  
• Preparation – Review the QA/QC reporting requirements from FHWA and project plans with the crew to ensure that all weighing, mixing, and testing forms are completed and to avoid non-compliance. Be sure to clean off equipment and forms of old concrete – the UHPC installation needs to stay free of contamination. Confirm that the materials and prefab elements on hand match the specifications.
  
  
• Field Casting – For UHPC projects, it’s important to ensure the substrate and/or precast components are completely clean so that the UHPC can bond against the surface (since UHPC often doesn’t contain coarse aggregate, seals need to be even tighter). Pay attention to the casting formwork and sequencing in the plans, which may be highly specific.
  
  
• Post-Placement – Ensure that the correct curing and measurement procedures are in place. Temperature readings and maturity curves will guide the completion timeline, and the engineer will have the final say on when the structure can be loaded. Surface grinding and formwork removal should be performed just as the UHPC reaches its minimum compressive strength. 
  
  
• Final Testing – Certain test results will not be available until after structural loading due to UHPC’s quick strengthening properties. Make sure any special tests, such as leak testing or extended cylinder break tests, are accounted for in the closeout process. 

A good UHPC vendor will be there for you along the way for construction verification where you need it.

FHWA – A Resource for Contractors

And there you have it – a project with stronger, more durable concrete and a straightforward plan for contractors. FHWA has brought UHPC a long way, and it continues to be a key resource for suppliers, engineers, and contractors. 

Whether you’re a seasoned firm taking on more UHPC projects or just getting acquainted with this material, be sure to partner with a UHPC vendor that has worked with real projects and provides expert technical guidance. At Cor-Tuf, we’ve designed our products to exceed agency requirements and tested them with real contractors. Take the step up from traditional concrete without reinventing the wheel. Your sand, your cement, our Cor-Tuf UHPC.