Tensile behavior of UHPFRC made by a fiber orientation device with adjustable vibrational frequency: Fid-Bau Portal

Tensile behavior of UHPFRC made by a fiber orientation device with adjustable vibrational frequency

Li, Zhihao / Zhou, Wei

Highlights • A fiber orientation device with adjustable vibrational frequency is designed. • The fiber orientation parameters are evaluated by the image analysis technique. • The tensile strength of UHPFRC under different vibration frequencies is predicted. • A reference for how to adjust vibration frequency when pouring UHPFRC is provided.

Abstract Ultra-High-Performance Fiber Reinforced Concrete (UHPFRC) not only has high compressive and tensile strength, but also exhibits strain-hardening characteristics in tension due to the addition of steel fibers. In this study, a new-style fiber orientation device equipped with a vibration motor of adjustable vibrational frequency was used to prepare UHPFRC. The wall effect and fiber length were considered in the manufacturing process of the device. Uniaxial tensile tests were conducted on fiber-oriented UHPFRC to explore the effects of vibrational frequency and corresponding vibrational force on the tensile behaviors. The test results showed that the elastic ultimate tensile strength, elastic ultimate tensile strain, tensile strength, peak tensile strain, and tensile elastic modulus of UHPFRC specimens cast by fiber orientation process at various vibrational frequencies were different. The fiber orientation parameters were quantitatively evaluated by the image analysis technique to explain the differences in tensile properties of the specimens. The effect of different vibrational frequencies on the tensile strength of UHPFRC matrix and its porosity was also considered. Therefore, this study provides a reference for how to adjust the vibrational frequency of the vibrating platform under the directional channel when pouring relevant components.