Title: Electromagnetic Sensor for the Nondestructive Testing of Ultra-High Performance Concrete

Author(s): Daniel J. Alabi, Megan S. Voss, Raid S. Alrashidi, Christopher C. Ferraro, Kyle Riding, and Joel B. Harley

Publication: Symposium Paper

Volume: 363

Issue:

Appears on pages(s): 21-37

Keywords: Concrete, NDT, Sensor, UHPC

DOI: 10.14359/51742105

Date: 7/1/2024

Abstract:
Ultra-high performance concrete (UHPC) has seen growing use in the construction industry because of its high compressive, tensile, and flexural strength. The tensile and flexural strength are in part due to the steel fibers added to the UHPC mix. Yet, fibers can segregate due to poor material rheological properties and construction practices, resulting in less than expected material strength. Due to the importance of these fibers, there is a need to verify the volume and orientation of the steel fibers in the UHPC. In this work, we report on the design and testing of electromagnetic sensor systems that are able to test the integrity of the steel fibers in the UHPC structure. We test our sensor system using UHPC samples containing 1% to 3% fiber content by volume and created a calibration based on the results. Our results show a linear relationship between the inductance change versus the fiber percentage with an R-squared value of 99.7 %, which shows that our approach successfully demonstrated the potential of using our approach for characterizing steel fibers in UHPCs.