Honors Theses
Date of Award
Spring 5-8-2026
Document Type
Undergraduate Thesis
Department
Mechanical Engineering
First Advisor
Damian Stoddard
Second Advisor
Yiwei Han
Third Advisor
Hunain Alkhateb
Relational Format
Dissertation/Thesis
Abstract
This research investigates the ballistics response and compressive strength of a Fly Ash/ Lunar Regolith hybrid geopolymer concrete developed for space construction. The study aimed firstly to optimize the Fly Ash/ Regolith mix ratio for maximum mechanical performance and secondly, to evaluate the effectiveness of carbon-fiber micro-truss reinforcement, produced by 3D printing, in mitigating damage from high-velocity impacts. Concrete specimens with varying Fly Ash-to-Regolith ratios (100-50% Fly Ash) were fabricated and tested under compression and ballistic loading. Compressive strength tests followed ASTM C109 using a 110 Kip 810-MTS testing apparatus on both unreinforced and reinforced 2” cubes. For unreinforced samples, average compressive strengths ranged between 4,002-5,485 psi with the highest compressive strength value corresponding to the 90% Fly Ash/ Regolith mix ratio. The lowest strength value was seen in the 60% Fly Ash mix ratio but only showed a 27% decrease from the optimal 90% mix. All the mixes achieved strengths within the range of standard structural concrete. The reinforced samples yielded compressive strengths in the 2237-3349 psi range with the highest strength value corresponding again to the 90% Fly Ash/ Regolith mix ratio which is consistent with the unreinforced sample results. While it did not increase compressive strength, reinforcing the samples seemed to homogenize results across Fly Ash/ Regolith mix ratios yielding similar compressive strength results as more Regolith was added when compared to the unreinforced sample set. Ballistic performance was assessed on 6x6x0.75” panels using a pneumatic launcher at 1000 psi. Energy absorption was found using the MotionPro Y4-S3 High Speed Camera with 1024x160 image resolution at 30,000 fps to perform Digital Image Correlation (DIC) with ProAnalyst (Woburn, MA) software. Unreinforced samples absorbed 105-130 ft-lb of impact energy, while reinforced samples absorbed 74-115 ft-lb, with both sets showing maximum absorption near the 80% Fly Ash/ Regolith ratio. Reinforcement did not increase overall energy absorption across all mix ratios but proved effective in localizing damage and preventing catastrophic failure - a critical factor for maintaining load-bearing capacity under impact. Overall, the optimal Fly Ash/ Lunar Regolith ratio was identified between 80-90% Fly Ash, offering a balance between compressive strength, energy absorption, and material efficiency. These results demonstrate that reinforced geopolymer composites incorporating lunar regolith simulants can provide durable, impact resistant, and sustainable materials for future lunar infrastructure.
Recommended Citation
Johnson, Phoebe G., "Ballistics Characterization of Micro-Truss Reinforced Lunar-Inspired Geopolymer Concrete for Space Construction" (2026). Honors Theses. 3367.
https://egrove.olemiss.edu/hon_thesis/3367
Included in
Mechanical Engineering Commons, Space Habitation and Life Support Commons, Structural Materials Commons