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Presenter: Michelle Barry | University of Arkansas
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Speaker Biography
Michelle L. Bernhardt-Barry is an Associate Professor within the Department of Civil Engineering at the University of Arkansas. She received her B.S., M.S., and Ph.D. in Civil Engineering from Texas A&M University in 2008, 2009 and 2013, respectively. Her research interests include the multi-scale characterization of particulate materials, with a specific focus on the use of traditional and advanced laboratory testing, discrete element method (DEM) modeling, and statistical methods to link fundamental material properties to the global observed behavior. While much of her work focuses on soil behavior, she has extended this to cemented particulates and other material types where bio-inspired designs and materials can be incorporated to optimize and tune the performance of load-carrying systems. Dr. Barry also researches and develops additive manufacturing and other emerging technologies for use in the construction of civil and military infrastructure. In 2018, she was awarded an NSF Faculty Early Career Development (CAREER) grant through which she has developed an additive construction technique focused on the bio-cementation of native soils for use in horizontal and vertical infrastructure. She is also currently leading a multi-million dollar project at the University of Arkansas focused on the use of indigenous soils in additive construction to enable military missions. This program is funded by the US Army Corps of Engineers Engineering Research and Development Center and is performed in partnership and as a sub-award to Applied Research Associate, Inc. In addition to research and teaching, Dr. Barry has gained professional experience in geotechnical and structural design and construction, forensic investigation, and project management, and she is a licensed professional engineer in Arkansas.
Co-authors/Co-presenters
Michelle L. Bernhardt-Barry, Ph.D., P.E., University of Arkansas
Jim Mantes, P.E., Applied Research Associates
J. Mikhael Erekson, P.E., Applied Research Associates, Inc.
Jaden A. Bennett, Applied Research Associates, Inc.
Ruimin Feng, Ph.D., University of Arkansas
Tim Nunez, University of Arkansas
James Michael Stewart, University of Arkansas
Bailey Downing, University of Arkansas
Casey Roberts, Robotic Construction Technologies
Matt Friedell, Robotic Construction Technologies
Eric Compton, Robotic Construction Technologies
Performance of Cast Grout and Foam Infilled Additive Construction Concrete Composites
Description
Combat engineers in the US Military are routinely faced with missions involving the construction of structures to either enhance or deter mobility. Construction of these items in a combat zone is very difficult due to the limited material options available and the large logistical footprint often associated with traditional construction solutions. Additive construction (AC) provides unmatched flexibility in manufacturing these structures directly in the field with native materials and has the potential to revolutionize the way battlefield mobility and counter-mobility construction missions are accomplished if the materials challenges can also be overcome.
Most AC concrete structures are printed as an open cellular pattern or as a formwork shell and then the cells are later cast with steel-reinforced concrete because the structural properties and behavior of the non-reinforced mortar-like material typically used for printing is not well understood. Furthermore, printing full infill is time-consuming and costly. In design calculations, engineers often ignore any strength provided by the AC shell because it is difficult to know the quality of the bonding, and the composite behavior is not well understood. This is even more true for novel infill materials such as insulating foams or elastomers that may be advantageous for various AC applications.
This presentation will focus on some of the latest research carried out as a part of the ACME Tech research program. ACME Tech (Additive Construction of Maneuver Enabling Technology) is comprised of researchers from Applied Research Associates, the University of Arkansas, Iowa State University, and Robotic Construction Technologies and is funded by the United States Army Corps of Engineers – Engineering Research and Development Center (USACE ERDC). The goal of the program is to advance AC technology by developing structural designs for mobility and counter-mobility items, material mixtures using indigenous materials, AC slicer software solutions, and a mobile AC equipment package for military construction.
As a part of the larger research mission, the team carried out a focused study examining the performance of AC concrete composites through a series of experimental tests and validated Discrete Element Method (DEM) models. A commercially available 3D printing mortar-type concrete material was used in this study. Cylindrical shells 6 inches in diameter by 12 inches tall were printed and tested in uniaxial compression under three different conditions: (1) concrete shell with no infill, (2) concrete shell with infill cast in the same concrete material, and (3) concrete shell with cast expansive foam infill at three different densities. A variety of material characterization tests were also carried out on cylinders of foam only and cylinders of the AC concrete material only to characterize the stiffness and mechanical response of these materials and provide data to calibrate the DEM models. During the experimental compression tests, thin-film pressure mapping sensors were used to measure the distribution of stress across the various materials and provide additional data for verification of the computational models. The results of these tests and the findings from the DEM models will be presented and discussed, along with findings from a full-scale model of a box culvert to further explore the efficacy of expanded foam and concrete infill and improve understanding of composite action between printed and infill materials.
Date and Time
Friday, November 8, 2024
10:00 AM - 11:30 AM
Location
Huntington Room
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