Dynamic Tensile and Stress Wave Transmitting Characteristics of High Strength and High Ductility Concrete

Abstract

High strength and high ductility concrete (HSHDC) exhibits excellent compressive and tensile properties, suitable for dynamic loads. However, the current understanding of HSHDC's dynamic tensile behavior is limited. To address this gap and facilitate the application of HSHDC in structural components, this study investigates HSHDC's dynamic tensile properties across a range of strain rates, from quasi-dynamic (10-5–10-1 s-1) to dynamic (141.3–169.0 s-1). Special clamps were used for consistent specimen testing, focusing on strain rate effects on tensile properties. Results showed significant strain rate sensitivity in HSHDC, especially in tensile strength, which varies less with strain rates compared to ordinary concrete. At high strain rates, HSHDC exhibits reduced tensile strain and energy absorption, indicating decreased ductility. This is attributed to micro-mechanical properties and stress wave effects on crack propagation. Digital image correlation (DIC) analysis reveals that under the influence of the first set of dynamic tensile waves, only one to two cracks propagate on the HSHDC surface, with measured tensile deformations ranging from 0.12% to 0.38%. However, due to the bridging effect of fibers, stress waves can continue to propagate through the crack surfaces within the specimen, leading to the generation and expansion of new multiple cracks.

Keywords: High strength and high ductility concrete (HSHDC), Dynamic mechanical properties, Strain rate sensitivity, Split Hopkinson tension bar