Martian Material Sourcing Challenges Propel Earth Construction Opportunities
Troemner, Matthew; Cusatis, Gianluca
2019, Vol. 1, Issue 3 pp. 547-549
Few places in our solar system have captured the collective imagination of society quite like Mars. Thoughts conjured include imagery of glass domes encapsulating skyscrapers and vast fields of solar arrays extending into the expanse—a truly futuristic landscape. However, when humans first arrive, the sight will be quite the opposite. Aside from a few rovers, the surface is desolate of earthly equipment or engineered-structures, anything astronauts will need must be transported or created on site. Mars offers substantial quantities of sand (or regolith) for construction, though it lacks in other typical building materials. Fortunately, an active geochemical sulfur cycle exists, providing an abundance of sulfur compounds on and near the surface. While not typical in modern industry, sulfur concrete was explored on Earth in limited applications. A study of Martian regolith sulfur concrete (Marscrete) has confirmed its use as a structural material, and even indicated significantly greater strengths than its traditional Earth-based counterpart. Harnessing the ability to efficiently translate disruptive 3D-printing technology to the world of construction remains an ongoing challenge. Martian fabrication will almost certainly require such automation, though—and thus, it must be addressed. While a feat on its own, confronting Martian material sourcing challenges may in fact propel opportunities for 3D-printing in Earth construction.
Notes on the AISC 360-16 Provisions for Slender Compression Elements in Compression Members
AISC Engineering Journal
Geschwindner, Louis F.; Troemner, Matthew
2016, Vol. 53, No. 3 pp. 137-146
Compression member strength is controlled by the limit states of flexural buckling, torsional buckling, and flexural-torsional buckling, as applicable. These compression members may buckle globally or locally, depending on the overall column slenderness and the local plate element slenderness for the plates that make up the shape. If any of the plate elements will buckle at a stress lower than that which would cause the column to buckle globally, the local buckling of the plate will control the overall column strength. When this occurs, the column is said to be composed of slender elements.
This paper will briefly discuss past specification provisions for slender element compression members and introduce the new provisions in the 2016 AISC Specification. It will present a simplification that reduces the number of constants that must be used and will present the specification requirements in an alternate format. Because the 2016 requirements result in different strengths than the 2010 requirements, figures are provided to illustrate the overall impact of these changes on column strength.
Five Steps to 3D-Printing a Home on Mars
Our team at Northwestern University is taking part in NASA’s 3D-Printed Habitat Challenge, exploring additive construction technology to create housing for deep-space exploration, including its 2033 mission to Mars. If you’re going to Mars for any extended period of time, it doesn’t make sense to send all of your resources from Earth — the transport costs would be enormous. So you have to produce habitats and structures using what’s already there on the planet’s surface, through 3D-printing or another manufacturing process.
We’re using a concrete based on sulfur. Sulfur is readily available on Mars, and it doesn’t need water. There is frozen water within the planet’s surface, but you’ll need that to live on, so we didn’t want to utilize such a precious resource as a building material. For testing, we’re mixing it 50/50 with a basalt-based simulant from the Mojave desert…
Specwise: What's New in the Spec?
Modern Steel Construction
Baer, Sam; Troemner, Matthew
AISC is set to release the 2016 edition of the Specification for Structural Steel Buildings (ANSI/AISC 360-16) in the near future.
Changes from the 2010 edition reflect the Committee on Specifications’ desire to implement only essential changes that reflect new research, provide for more efficient designs or broaden its scope. Many of these changes were technical in nature, though edits were also made that focused on improving usability, transparency and editorial content.
The following is a brief overview of the most significant changes, some of which have the potential to substantially affect design procedures. A complete list of differences between the 2010 and 2016 AISC Specification will soon be available as a free download at www.aisc.org/manualresources.
Prequalified Connections for Special and Intermediate Steel Moment Frames for Seismic Applications
ANSI/AISC 358-16 American National Standard
Connection Prequalification Review Panel
Arber, L., Carter, C., Duncan, C., Malley, J., Miller, D., Pryor, S., Saunders, C., Troemner, M.
ANSI/AISC 358-16, Prequalified Connections for Special and Intermediate Steel Moment Frames for Seismic Applications, was developed using a consensus process in concert with the Specification for Structural Steel Buildings (ANSI/AISC 360-16) and Seismic Provisions for Structural Steel Buildings (ANSI/AISC 341-16). ANSI/AISC 358-16 is incorporated by reference into the Seismic Provisions.
This Standard specifies design, detailing, fabrication and quality criteria for connections that are prequalified in accordance with the AISC Seismic Provisions for Structural Steel Buildings (herein referred to as the AISC Seismic Provisions) for use with special moment frames (SMF) and intermediate moment frames (IMF). The connections contained in this Standard are prequalified to meet the requirements in the AISC Seismic Provisions only when designed and constructed in accordance with the requirements of this Standard. Nothing in this Standard shall preclude the use of connection types contained herein outside the indicated limitations, nor the use of other connection types, when satisfactory evidence of qualification in accordance with the AISC Seismic Provisions is presented to the authority having jurisdiction.
The American Ceramic Society, Advances in Cement-Based Materials 2019
Large-Scale 3D Printing of Infrastructure Materials
Other Publication Contributions
Consulting CAD Drafter
Geschwindner, Louis F., et al. Unified Design of Steel Structures. Providence Engineering Corp, 2017.
Blog Guest Contributor
Troemner, Matthew. Students, Prepare To Launch Your Concrete Canoes! BuiltWorlds, 2016.
Blog Guest Contributor
Troemner, Matthew. Concrete, Canoes, Cramming and Caffeine. BuiltWorlds, 2016.