Water saturation effect on the dynamic tensile behavior of high ductility concrete

Abstract

Ultra-high toughness cementitious composites (UHTCC) are suitable for hydraulic structures due to their enhanced ductility and effective crack control capacity. This research investigated the dynamic tensile behavior of two different types of UHTCC: one featuring a normal strength matrix reinforced with polyvinyl alcohol (PVA) fibers, and another combining a high-strength matrix with polyethylene (PE) fibers. The findings revealed that water saturation effect on the dynamic tensile behavior of two types of UHTCC were opposite. After saturation, normal UHTCC made with PVA fibers exhibited increases in tensile strain capacity, while UHTCC made with PE fibers and high-strength matrix exhibited reduction in deformation by 56 %. Under dynamic tensile loading, moisture content notably affected the strain rate sensitivity of tensile properties in normal UHTCC with PVA fibers, demonstrating significant variations in DIF (Dynamic Increase Factor) for strength, deformation, and energy dissipation. However, these influences were minimal in composites made with a high-strength matrix and PE fibers. The mechanism for such phenomenon were discussed based on the result of matrix fracture test and fiber pull out test.