Proportion and Evaluation of Ultra-High Performance Concrete Using Local Materials

Ultra-high performance concrete (UHPC) is a new class of concrete that has superior workability, as well as mechanical and durability properties that far exceed those of conventional concrete. To achieve these properties, a very dense internal structure and the very low water-to-binder ratio (w/b) generally are necessary. While particle packing models are typically used to design UHPC, due to the complexity of the composition interaction and characteristics of UHPC, these models might not necessarily provide the best design, which leads to the need of experimental study to justify UHPC performance. The evaluation of the impact of various design parameters on the properties of UHPC is also needed. A study and evaluation were performed with multiple series of UHPC mixtures prepared with different design parameters and considerations. The impacts of different aggregate, types of fibers, High Range Water Reducing (HRWR), w/b, types of cement, types and quantities of supplemental cementitious materials (SCMs), and different total binder content on UHPC performance were presented. Furthermore, the extensive amount of fine materials, the absence of coarse aggregate, and the very low w/b often make the process of UHPC production challenging. This study included evaluations of the impacts of mixers on the properties of fresh and hardened UHPC. The comparison of these mixers was used to determine whether mixtures developed in the laboratory were comparable to those used in the field. Advisor: Jiong Hu