Recent advances in ultra-high-performance concrete (UHPC) have opened new frontiers in shotcrete technology, allowing the material’s unparalleled strength, durability, and bond performance to be delivered through accelerated, placement-efficient methods. UHPC shotcrete is emerging as a next-generation solution for structural rehabilitation, tunnel linings, slope stabilization, and form-free architectural applications. This session will highlight innovative developments in UHPC shotcrete mixture design, including fiber dispersion, rheological control, accelerator compatibility, and pumpability optimization. Presenters will share case studies and experimental findings on mechanical performance, interlayer bonding, and field implementation challenges. The session will also explore the interplay between material design and application technologies—such as nozzle configurations, curing regimes, and robotic spraying—paving the way for broader industrial adoption. By integrating laboratory research and field practice, this session aims to showcase the transformative potential of UHPC shotcrete in modern construction and repair.
Learning Objectives:
(1) Describe current innovations in UHPC shotcrete mixture design, including fiber dispersion, rheology, and admixture optimization;
(2) Understand performance metrics and testing methods relevant to UHPC shotcrete applications, such as bond strength, durability, and in-situ density;
(3) Analyze case studies demonstrating UHPC shotcrete applications in infrastructure repair, tunneling, and slope stabilization;
(4) Evaluate challenges and emerging technologies for large-scale UHPC shotcrete deployment, including equipment, curing, and field quality control.
Demonstration of a Sprayable form of UHPC for Accelerating Bridge Construction
Presented By: Sri Sritharan
Affiliation: Iowa State University
Description: Accelerated Bridge Construction (ABC) has been widely used for superstructures. Some efforts have also been made to apply ABC to substructure construction, including columns and footings. However, their practical application has been limited due to the need to transport heavier sections and establish reliable connections between prefabricated components. To address these challenges, a new concept has been developed that uses stay-in-place shells made from Ultra-High Performance Concrete (UHPC) to simplify construction and allow the use of in-situ concrete without causing construction delays. This concept was demonstrated in a half-scale column-pile-pile cap system, where UHPC shells were used for the column and pile cap, along with steel H-piles. These shells were created using a sprayable form of UHPC. The presentation will cover construction details and the performance of the test structure under load combinations suitable for both seismic and non-seismic regions.
Shotcreteing UHPC with High Tensile Steel Fibers
Presented By: William Kulish
Affiliation: Steelike, Inc.
Description: To successfully apply UHPC as shotcrete, the material must first be pumped reliably and consistently over extended periods. Only once stable pumpability is achieved can effective spraying be expected. This must be accomplished without simply adding extra water or additional SP/HRWR, as such adjustments can compromise the intended performance of the mix.
Success also depends heavily on using the right equipment. This includes an appropriately sized generator and air compressor, as well as a pumping system that does not excessively heat the material during pumping and can be cleaned efficiently after use. In practice, robust shotcrete application of UHPC requires not only a suitable mix design, but also careful alignment between material behavior, pumping method, and equipment setup.
Enhancing the Blast Resistance of Masonry Walls through High-Performance Shotcrete
Presented By: Hassan Aoude
Affiliation: University of Ottawa
Description: Unreinforced masonry (URM) walls are particularly vulnerable to out-of-plane blast loads due to the lack of internal steel reinforcement and their brittle response. The presentation describes an experimental study investigating a retrofit strategy aimed at improving the blast performance of such walls. The experiments consisted of shock-tube tests conducted on URM wall specimens subjected to controlled blast loading. Selected specimens were retrofitted by applying a thin layer of high-performance shotcrete to the tension face of the wall. The results show that the shotcrete retrofit significantly enhanced blast resistance, leading to reduced out-of-plane displacements and an overall improvement in structural response compared to unretrofitted walls.
Ready-Mix UHPC and Large-scale Scale Shotcrete
Presented By: Rich Burgess
Affiliation: Cor-Tuf UHPC
Description: Another important aspect is the ability to produce and deliver UHPC in large ready-mix batches while maintaining sufficient workability over time for successful pumping and shooting. The material must remain stable and workable long enough to move from the truck through the pumping equipment and into application without interruptions, blockage, or loss of performance.
I would also like to include video clips of the application process, as these can help illustrate practical aspects of handling, pumping, and spraying that are difficult to convey through text alone. In addition, I plan to share test data from the different applications to demonstrate how the material and process performed under varying field conditions.
Key Factors Governing Successful UHPC Shotcrete Application
Presented By: Marc Jolin
Affiliation: Laval University
Description: This presentation will discuss practical and technical aspects of UHPC shotcrete application, with emphasis on achieving reliable pumpability, stable spraying, and consistent field performance. Topics will include mix workability over time, large ready-mix batch delivery, equipment selection, and lessons learned from field applications, supported by video footage and test data.