Determining the Elastic Modulus of Ultra-High Performance Concrete using Ultrasonic Pulse Velocity Tests
Authors: Jake Freedman, Daniel Alabi, Joel B. Harley
Faculty Mentor: Joel B. Harley
College: Herbert Wertheim College of Engineering
Ultrasonic pulse velocity testing is a well-established non-destructive evaluation method. By sending an ultrasonic pulse through a material and recording its travel time, characteristics of the material can be determined: elasticity, strength, etc. Concrete’s widespread use makes non-destructive evaluation of its condition essential, and its heterogeneity makes UPV tests complex compared to other materials, as non-uniform characteristics create irregular patterns, obscuring the signal recorded. Extensive research has been conducted on UPV testing in concrete, but a gap exists in determining its accuracy in ultra-high performance concrete. Characteristics of UHPC, including greater compressive strength and density, may affect the test’s accuracy. This project investigated the ability to determine UHPC’s elasticity using ultrasonic pulses. Elasticity is the “stiffness” of a material, which dictates the amount it shifts under load. Accurate determination of elasticity would support that techniques used to evaluate regular concrete hold in UHPC. Elasticity was calculated by recording the travel time of an ultrasonic chirp across the width of a 10x10x35.5 cm prism. Velocity was calculated by dividing the width by time. Three UHPC samples had an average elasticity of 3931 ksi, outside of the expected range of 4000-8000 ksi, determined by the manufacturer, the University of Florida.
Click the video below to view the student's poster pitch.