Non-Proprietary Ultra High Performance Concrete Mixture Design Using Response Surface Methodology

Ultra-High-Performance Concrete (UHPC) is an advanced cementitious material known for its exceptional mechanical strength and durability. However, the high cost of proprietary UHPC formulations has hindered its widespread adoption. Thus, this study aims to develop a non-proprietary UHPC mixture using locally available materials in Utah. To efficiently optimize the mixture design, Response Surface Methodology (RSM) was used to evaluate the effects of key mixture variables on UHPC performance. A total of 28 preliminary mixture designs were generated utilizing Central Composite Design (CCD), and their compressive strengths were tested. Although none of the initial mixtures met the target compressive strength, further investigation identified that inadequate end surface preparation likely contributed to the low strength results. Despite this issue, the data were used to build a statistical model to assess the influence of mixture components on compressive strength. Analysis of Variance (ANOVA) confirmed the model’s significance, with an adjusted R<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> value of 85.41%. This statistical approach highlights the potential for developing non-proprietary Utah-based UHPC mixtures for practical infrastructure applications, minimizing reliance on trial-and-error testing. Ongoing work is focused on refining the mix design, re-evaluating compressive strengths with proper specimen preparation, and assessing the optimized mixture formulation through material characterization and large-scale casting.