Determining the Elastic Modulus of Ultra-High Performance Concrete using Ultrasonic Pulse Velocity Tests

Jake Freedman

Authors:  Jake Freedman, Daniel Alabi, Joel B. Harley

Faculty Mentor:  Joel B. Harley

College:  Herbert Wertheim College of Engineering

Abstract

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.

Poster Pitch

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Poster

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Eli Nir
Eli Nir (@guest_1642)
1 year ago

Looks interesting! Are you planning on conducting the future tests soon?

Jake Freedman
Jake Freedman (@guest_7720)
Reply to  Eli Nir
1 year ago

Hi Elir,

I am not sure what direction I will be taking this project going forward, though I think conducting more tests on related parameters using the same method could be the next step.

Patricia Perez
Patricia Perez (@guest_2036)
1 year ago

Hey Jake, great poster! Is the method of testing that you tested something that is usually used on that type of concrete, more so was it something that was in the works already to be applied/modified to test this concrete?

Jake Freedman
Jake Freedman (@guest_7722)
Reply to  Patricia Perez
1 year ago

Hey Patricia,

That method is very common in regular concrete, but hasn’t been tested very much in this specific type of concrete. The hope was that this test would work to validate that the method applies to this type of concrete as well. Thank you for commenting!

Lauren Rogers
Lauren Rogers (@guest_2524)
1 year ago

Hi Jake, great presentation! How are you going to determine a more representative equation or Poisson’s ratio? Are there any indicators to why the ones you initially used may be incorrect?

Jake Freedman
Jake Freedman (@guest_7724)
Reply to  Lauren Rogers
1 year ago

Hi Lauren,

Those are great questions, and I’m not quite sure. With regards to the Poisson’s ratio in particular, there is a fairly wide range of value that are typically used for ultra-high performance concrete, so it is very possible that the ratio used was not accurate. As far as determining any potential changes to the equation, I think that using the same ultrasonic testing method, but applying it to calculating a different parameter, could shed more light on why the elasticity measurement fell below the expected range and what adjustments could be made. Thank you!

Andres Osuna
Andres Osuna (@guest_2880)
1 year ago

For future work, do you plan on changing tests methods or adapt parameters?

Thank you and great work!

Jake Freedman
Jake Freedman (@guest_7726)
Reply to  Andres Osuna
1 year ago

Hey Andres,

Thanks for your question! I think that altering the equation or parameters could lead to this method calculating the correct values for elasticity and other metrics, so I think that I can do further work with the same testing method.