Development of Non-Proprietary Ultra-High-Performance Concrete and Determining Tensile Testing Methodology

Abstract

Ultra-high-performance concrete (UHPC) is a unique material due to having post-cracking tensile strength. To utilize this material in design and construction, a method must be used to test the tensile strength of UHPC. This thesis aims to determine a recommended tensile testing method and develop a non-proprietary UHPC that meets the Federal Highway Administration (FHWA) requirements for UHPC. The development of non-proprietary UHPC was accomplished by testing different mixtures with varying raw materials. The raw material variables tested were the steel fiber dosage, silica fume dosage, fine aggregate gradation, and water-binder ratio. Both objectives were accomplished by testing the compressive, flexural, and tensile strength of UHPC. Based on the materials tested, a steel fiber dosage of 1.5% is recommended for UHPC as it provides sufficient toughness and post-cracking tensile strength. An inverse analysis was performed to correlate the flexural strength to tensile strength. The results of this study indicate that steel fibers are the only raw material tested that significantly affected the tensile and flexural strength. Flexural testing is recommended for UHPC because it provides more reliable results when compared to uniaxial tensile testing.