US Military combat engineers are routinely faced with missions involving construction of structures that enhance or deter mobility. Construction of these items in a combat zone is very difficult due to limited material options available. Further complicating construction in a combat zone is the large logistical footprint of traditional construction solutions. Additive construction (AC) is a potential revolutionary method to change the way battlefield mobility and counter mobility construction missions are accomplished. The ACME Tech (Additive Construction of Maneuver Enabling Technology) is a research program funded by the United States Army Corps of Engineers – Engineering Research and Development Center (USACE ERDC) with a goal to advance AC technology by developing structural designs for mobility and counter mobility items, developing material mixtures using indigenous materials, developing AC slicer software solutions, and developing a mobile AC equipment package for military construction. The research program is supported by researchers from Applied Research Associates, University of Arkansas, Iowa State University, and Robotic Construction Technologies.
A common need for mobility on the battlefield is the placement of concrete box culverts for vehicle and soldier crossings. Precast concrete box culverts are a common choice for this application because they can be installed rapidly and require little maintenance. Precast concrete offers the advantage of high-quality materials as well as control and consistency during fabrication. However, typical precast box culverts can range in weight from 1,500 kg/m (approximately 1,000 lb/ft) to over 12,000 kg/m (approximately 8,000 lb/ft). Shipping such large and heavy structures is costly and provides logistical challenges in successful delivery and placement at a desired location. As a result, AC is seen as an ideal solution whereby indigenous materials can be used to produce AC mixes, which can then be employed to print box culverts and subsequently place them in the field with significantly reduced resources for production since only the printing equipment and limited materials would need to be transported to the desired location.
One notable challenge with utilizing AC for producing box culverts is that structural performance of the printed concrete is not well understood beyond compressive behavior. At the present time, printed concrete is not typically relied on for significant shear, flexural, or composite response. Culvert geometry does not lend itself well to designs or printing patterns that are predominantly loaded in compression only. Loads from surrounding soil, water, and surcharges from foot or vehicle traffic result in notable shear and flexural loads that must be resisted by the box culvert design. A combination of structural design, finite element analysis, and physical testing have been leveraged to better understand the ability of AC to handle these kinds of load combinations and a preliminary design approach for printed box culvert sections. The developed approach allows for modifications based on varying material properties and potential bonding and composite action of the AC box culvert concept.

Date and Time
Friday, November 8, 2024
10:00 AM - 11:30 AM

Location
Huntington Room

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