micro-XRCT data sets of ultra high performance concrete cores during different stages of high-frequency fatigue testing with 50 Hz

Abstract

The dataset contains micro X-ray computed tomography (micro-XRCT) data from cylindrical ultra-high-performance concrete (UHPC) cores examined at different stages of high-frequency fatigue damage. Each core had a diameter of 6.35 mm and a length of 16 mm. The cores were extracted from the same UHPC block. However, different cores were imaged at the different damage stages; therefore, the dataset does not represent repeated imaging of the same core. The investigated stages were the undamaged condition (Phase I), an intermediate damaged condition between Phases II and III, and the advanced damaged condition (Phase III). The fatigue test associated with the micro-XRCT measurements was performed at a loading frequency of 50 Hz and a mean axial stress of 100 MPa. The stress amplitude was approximately 30% of the compressive strength. Based on a compressive strength of approximately 150 MPa, this corresponds to a stress amplitude of approximately 45 MPa. The fatigue specimen failed after approximately 240,000 loading cycles. The dataset includes two-dimensional X-ray projection images acquired at different angular positions and reconstructed cross-sectional images. Together, the reconstructed image slices represent the three-dimensional internal structure and fatigue-induced damage of the UHPC cores. The reconstructed data are organized according to the investigated damage stages: Phase I, undamaged condition: reconstructed_phase_I.tar.gz (scan identifier: 20230719_01) Phase II/III, intermediate damaged condition: reconstructed_phase_II-III.tar.gz (scan identifier: 20230320_01) Phase III, advanced damaged condition: reconstructed_phase_III.tar.gz (scan identifiers: 20240521_01_center and 20240521_01_top) The micro-XRCT measurements were performed using the modular cone-beam micro-XRCT system at the Institute of Applied Mechanics, University of Stuttgart. The system consists of an X-ray source, a rotary specimen stage, and a flat-panel detector. A detailed description of the system is provided by Ruf and Steeb (2020): Ruf, M., & Steeb, H. (2020). An open, modular, and flexible micro X-ray computed tomography system for research. Review of Scientific Instruments, 91(11), 113102. https://doi.org/10.1063/5.0019541 In addition to the micro-XRCT data, the archive UHPC_Fatigue_results.tar.gz contains raw measurement data from high-frequency fatigue tests conducted at loading frequencies of 20, 50, and 100 Hz. The data are organized into three folders according to the applied loading frequency. The raw measurement files are stored in the Perception Native Recording File format (*.pnrf). The signals were acquired using an HBK Genesis HighSpeed data-acquisition system and recorded using HBK Perception software. The files can be opened and analyzed using Perception. Information about the software is available on the official HBK Perception webpage. The software and the PNRF Reader Toolkit are available from the HBK software download page. The recorded measurement channels include: sample_L: Longitudinal displacement of the specimen. sample_q: Transverse displacement of the specimen. dms_1 and dms_2: Actuator displacement signals used as reference signals during the fatigue test. kmd: Output-voltage signal from the universal testing machine (UTM) load cell, which is used to determine the applied axial force. Pt-1000: Temperature signal recorded using a platinum resistance thermometer during the fatigue test.