In the coldest corners of the world, building anything becomes a race against nature. Sub-zero temperatures crack concrete, freeze machinery, and turn even the simplest task into a test of endurance. For military forces, disaster relief teams, and researchers operating in these unforgiving environments, having reliable infrastructure isn’t a convenience – it’s the difference between mission success and failure.

To address that challenge, the U.S. Army Corps of Engineers (USACE) is researching new approaches to additive construction (AC)—applying additive manufacturing or 3D printing techniques to construction —at its Cold Regions Research and Engineering Laboratory (CRREL), alongside the Construction Engineering Research Laboratory (CERL), two of seven laboratories in the U.S. Army Engineer Research and Development Center (ERDC).

Their goal: to explore how using ice as a construction material can reduce risk, simplify logistics, and enable safer, more efficient infrastructure in extreme cold environments. To learn more about this research, we sat down with materials science and engineering leaders from across the USACE, including:

• Kiera Thompson Towell, Research Materials Engineer at CRREL.
• Emily Asenath-Smith, Research Materials Engineer and Advanced Materials Team lead at CRREL.
• Megan Kreiger, Mechanical Engineer, DoD Subject Matter expert for AC, and AC research program area lead at CERL.

During our discussion, we explored CRREL’s mission, the origins of its 3D-printed ice research, the benefits and processes behind 3D printing with ice, and how this work supports broader defense applications.

GovDesignHub (GDH): Can you tell our readers what CRREL is, and what prompted the USACE CRREL team to explore 3D printing with ice in the first place?

Emily Asenath-Smith: The Engineer Research and Development Center (ERDC) serves as the research arm of USACE and is made up of seven laboratories, including CRREL and CERL.

CRREL is the federal government’s only laboratory dedicated to cold regions research, giving us a unique mission space. Within CRREL, the Advanced Materials Team studies ice both as an adversarial material and as a resource for cold regions operations. To develop ice as a resource, we focus on the materials science of ice and explore how additives can be used to manipulate its properties.

In 2021, building on this research, we constructed a free-standing bridge made from a high-performance ice composite. The bridge was able to support both the static load and dynamic crossings of a military-grade High Mobility Multipurpose Wheeled Vehicle (HMMWV).

However, the spray methods used to build the bridge were labor-intensive, leading us to explore ways to reduce the time and manpower required to construct ice structures for military operations in cold environments. That work ultimately led to a collaborative effort with the Additive Construction (AC) team at CERL, to develop the capability to 3D print ice materials at CRREL.

Megan Kreiger: AC is actually one of the core competency areas at CERL. Since 2014, we’ve been developing and testing the capability to 3D print custom-designed expeditionary structures on demand, directly in the field, using locally available materials.

While most of our AC efforts have focused on concrete, we’ve also explored other materials such as polymers, foams, clays, indigenous materials, and polymer concretes. However, many of these materials face temperature limitations and logistical challenges that make them less suitable for cold regions.

“This construction method could support a variety of Arctic operations for both the Army and USACE through engineering projects such as building shelters, repairing or reinforcing roads, and carrying out other construction tasks that typically rely on materials that are logistically difficult to source and transport to cold environments.” –Kiera Thompson Towell

That’s where our long-term collaborative effort with CRREL comes in. Together, we’re working to develop large-scale ice printing capabilities—enabling AC with ice at the scale of buildings and infrastructure.

GDH: What are the potential safety benefits, both in terms of physical risk and operational resilience, of using this approach versus traditional ice construction?

Kiera Thompson Towell: Traditional ice construction typically involves manually sawing into ice sheets and removing blocks to build structures by hand. Similarly, ice roads and bridges are created by spraying or flooding cold water over large areas of frozen ice sheets to thicken them.

Unfortunately, both methods are extremely labor-intensive and require personnel to spend long periods working in wet, sub-freezing conditions, leading to significant energy expenditure and a high risk of cold-related injuries such as frostbite and hypothermia.

Megan Kreiger: Not only can it help keep operators safe, compared to traditional ice construction methods, AC offers potential benefits such as reduced logistics requirements, fewer man-hours, lower costs, and shorter build times.

“Not only can it help keep operators safe, compared to traditional ice construction methods, AC offers potential benefits such as reduced logistics requirements, fewer man-hours, lower costs, and shorter build times.” –Megan Kreiger

Consequently, AC can improve performance, increase resiliency, and provide greater flexibility to produce needed infrastructure on-site or near-site in a more agile way. Many of these same advantages apply to AC with ice as well.

GDH: What kinds of real-world defense scenarios or Arctic operations do you envision this being used in? How does this research fit into USACE’s broader mission of engineering support in extreme environments?

Kiera Thompson Towell: This construction method could support a variety of Arctic operations for both the Army and USACE through engineering projects such as building shelters, repairing or reinforcing roads, and carrying out other construction tasks that typically rely on materials that are logistically difficult to source and transport to cold environments.

Megan Kreiger: That’s completely correct. I would add that AC typically provides the greatest benefit to the military in expeditionary or remote areas where logistics—such as shipping and equipment—are challenging, and where there are concerns about labor availability or risks to personnel.

“AC methods, regardless of the material used, serve as a valuable tool in the construction toolkit, enabling the ability to build in challenging environments where traditional methods may fall short. This includes potential applications in high-availability disaster recovery (HADR) scenarios, where speed, flexibility, and adaptability are critical.” –Megan Kreiger

AC with ice extends that capability to cold regions, enabling structures to be printed in environments where traditional construction is especially difficult.

Looking ahead, these ice-printed structures will be able to incorporate advanced geometries, allowing for not only more efficient construction but also improved performance thanks to greater design flexibility.

GDH: Can you walk us through what the additive manufacturing process looks like when you’re working with ice?

Emily Asenath-Smith: This process requires carefully formulating ice mixtures to achieve the right flow properties—also known as rheology—and thoughtfully integrating components to mix, transport, and extrude the mixture.

Kiera Thompson Towell: I would add that the process for additive manufacturing with ice is very similar to the extrusion method used with concrete. After developing an initial design, we 3D print in a cold room at CRREL that can be set to various temperatures, down to -30°C.

Next, we mix cold water with reinforcing materials or other modifiers until we achieve the desired rheological properties. The mixture is then pumped from its container or ‘hopper’ to the nozzle, where it’s extruded layer by layer in the programmed geometry. Each layer is allowed to freeze sufficiently before the next layer is added.

GDH: What kinds of tools or printing systems are you using to create these structures?

Kiera Thompson Towell: We use a combination of commercial software and custom coding to design the structures, create wall patterns, and generate the G-code that controls the printer and pump. For smaller projects—like desktop printing of an ice dollhouse—we used a modified commercial 3D printer. Currently, we’re working with a custom printer designed and built by the AC team at CERL.

GDH: What are some of the unique engineering or material challenges that arise when 3D printing with a substance like ice? How are you able to maintain structural integrity with ice during printing?

Kiera Thompson Towell: One of the biggest challenges in this process has been ensuring that each printed layer freezes properly to create a strong, stable foundation for the next. If a layer doesn’t freeze thoroughly enough, it won’t provide the necessary support, compromising the structural integrity of the entire build.

GDH: You’ve mentioned using cellulose nanofibers as part of the ice printing process. Why was this chosen, and how do they compare to other reinforcement options for ice structures? Are there other advanced materials or additives you’re experimenting with to further improve durability or performance?

Kiera Thompson Towell: Cellulose nanofibers (CNFs) are naturally occurring, biodegradable fibers found in plant matter. They have a very high strength-to-weight ratio and provide strong tensile reinforcement—an important characteristic, since ice is naturally weak in tension.

At just 0.3 percent by weight, CNFs can tremendously increase the flexural strength of ice, offering a comparable strength increase to other reinforcing materials but with much lower fiber content. We’re also experimenting with additional additives to enhance the performance of our ice composites further.

“Because of the melt resistance of CNF ice composites, there’s potential for their use in stabilizing existing and natural frozen structures—such as embankments and permafrost—in cold regions. More broadly, the ability to create low-cost, ice-based shelters using this material opens up a range of possible applications for both military and civilian purposes in cold environments.” –Emily Absenath-Smith

Emily Asenath-Smith: Our team was actually the first to report that CNFs not only strengthen ice but also slow its melting rate and help stabilize it when exposed to thawing conditions. CNFs can also be used to adjust the reflectivity of ice.

GDH: How close are we to seeing this technology used operationally in the field? Are there major technical milestones or hurdles your team is working to overcome?

Megan Kreiger: Our cross-laboratory team developed the ice printing system with the goal of scaling it to construction size. Most components of the system can be scaled up with only minor adjustments. Right now, the focus is on refining consistency with the smaller-scale printing system before moving on to larger prints.

GDH: Could this research have applications outside of defense, such as in climate science, polar research, or even humanitarian missions in cold regions?

Emily Asenath-Smith: Because of the melt resistance of CNF ice composites, there’s potential for their use in stabilizing existing and natural frozen structures—such as embankments and permafrost—in cold regions. More broadly, the ability to create low-cost, ice-based shelters using this material opens up a range of possible applications for both military and civilian purposes in cold environments.

Megan Kreiger: AC methods, regardless of the material used, serve as a valuable tool in the construction toolkit, enabling the ability to build in challenging environments where traditional methods may fall short. This includes potential applications in high-availability disaster recovery (HADR) scenarios, where speed, flexibility, and adaptability are critical.

To learn more about the Cold Regions Research and Engineering Laboratory, click HERE.

Featured image courtesy of USACE, by Justin Campfield, depicting Kiera Thompson Towell holding a 3D printed ice dollhouse made at CRREL.