CHAMPAIGN, Ill. – Since 2015, scientists and engineers at the U.S. Army Corps of Engineers (USACE), Engineer Research and Development Center (ERDC), Construction Engineer Research Laboratory (CERL) have been exploring expeditionary additive construction technology, also known as construction scale 3D printing.
The first research project, Automated Construction of Expeditionary Structures (ACES), has since developed into the Additive Construction (AC) program. The program focuses on a wide range of technological developments, including printers, deployment exercises, printable concrete materials, functional construction and reinforcement practices, materials testing methods and structural testing.
Over the last three years, military personnel from all throughout the Department of Defense have been introduced to this new technology during six separate demonstrations. In April 2018, CERL trained Army engineers from the U.S. Army Forces Command, 5th Engineer Battalion and the 416th Theater Engineer Command in the printing of various infrastructure elements at the Maneuver Support, Sustainment, Protection and Integration Experiment (MSSPIX), at Fort Leonard Wood, Missouri.
In December 2018, the AC program led a cross-branch Department of Defense exercise, where Marines, Sailors and Airmen were trained to print a three-foot wide, 32-foot pedestrian bridge that was designed to withstand 15,000 pounds per section. The AC team tested the bridge beams in 2019 at ERDC-CERL’s structural load floor facility and verified that the bridge beams were able to support up to 45,000 pounds.
Since the development of the program, the AC researchers have developed and co-developed over five different large-scale printers and have successfully printed two full-scale 512 square foot buildings, smaller-scale structures and infrastructure, including guard shelters, Jersey barriers, t-walls, culverts and bridges. Combining these different applications has led to many unique opportunities for further development.
According to Megan Kreiger, a CERL mechanical engineer and the technical lead for the AC program and 3D printing at ERDC, 3D printing has many capabilities and CERL is just beginning to analyze and develop more ways to use these resources to help protect the warfighter.
“Currently we are working on preparing the technology for its next real step towards acceptance and testing in field conditions,” she said. “We foresee printing various structures, including bridges, over the next three years. The initial bridge was a proof of concept and went from request to print within three months, which displayed the timely capability of 3D printing for infrastructure requests.”
“In the works, we currently have plans to print another bridge, with an end product that is more robust and refined for its application,” she continued. “In addition to the research performed in our laboratory and through field tests, the AC program is collaborating with stakeholders and external partners to drive this technology forward as a future industry standard.”
As leading experts in their field, CERL collaborates with large-scale 3D printing industry players and has a Cooperative Research and Development Agreement, or CRADA, with Caterpillar to develop this technology.
Researchers from the AC program also serve as members of the scientific committee and planning committee for the Transportation Research Board International Conference on 3D Printing and Transportation and judges for NASA’s 3D printing Centennial Challenges. The CERL ACES team serves as committee members, moderators and co-chairs with the American Concrete Institute, the American Society for Testing and Materials and the American Society of Civil Engineers. Through this involvement, their technical expertise contributes to the establishment of guidelines and standards for the adoption of the technology within the construction industry.