Wang et al. (2016) — Development of Near-Zero Water Consumption Cement Materials via the Geopolymerization of Tektites and Its Implication for Lunar Construction

Citation

Wang, K.-T., Tang, Q., Cui, X.-M., He, Y., & Liu, L.-P. (2016). Development of near-zero water consumption cement materials via the geopolymerization of tektites and its implication for lunar construction. Scientific Reports, 6, 29659.

DOI: 10.1038/srep29659
Atlas layer: external
Related Victor Li book chapter: Chapter 4: Matrix Microstructure & Chapter 9: Green ECC (Water Conservation & Closed-Loop Resource Cycling, pp. 307–342)
Source PDF: wang-2016-development-of-near-zero-water-consumption.pdf
Extracted text: full_text/wang-2016-development-of-near-zero-water-consumption_full_text.md
Source note: source_notes/wang-2016-development-of-near-zero-water-consumption_source_note.md

Why this paper matters

A breakthrough study published in Scientific Reports (Nature Portfolio) demonstrating the closed-loop, near-zero water consumption mechanism of geopolymerization using lunar regolith glass analogs (tektites), proving that over 90 % of batch water can be vacuum-recovered and recycled while withstanding extreme thermal vacuum cycling (102.4 K to 387.1 K).

Main contribution

Develops an inorganic geopolymer cementitious material using tektite powder (natural impact glass simulating lunar regolith chemistry) and a 5 M NaOH activator.
Discloses the closed-loop "near-zero water consumption" mechanism: water functions purely as a reaction medium for aluminosilicate dissolution and transport, which is subsequently released during polycondensation and can be $> 90\%$ recovered under vacuum.
Demonstrates that vacuum dehydration of free water does not degrade the 3D cross-linked N-A-S-H polymer framework, achieving compressive strengths of 15.2 to 22.5 MPa.
Verifies extreme environmental durability under lunar conditions: withstands high vacuum ($-0.096\text{ MPa}$) and severe thermal shock cycling between liquid nitrogen temperature ($102.4\text{ K} / -170.8\ ^\circ\text{C}$) and peak solar heating ($387.1\text{ K} / +114.0\ ^\circ\text{C}$).
Establishes the thermodynamic and logistical feasibility of clinker-free, water-recycling geopolymer construction for extra-terrestrial habitats and arid, water-scarce terrestrial regions.

Evidence summary

Material Formulation & Regolith Analogy:
Raw material: Lei Gong Mo tektite natural glass ($69.8\%\ \text{SiO}_2, 12.2\%\ \text{Al}_2\text{O}_3, 2.2\%\ \text{CaO}, 5.5\%\ \text{FeO}_T$, ground $< 74\ \mu\text{m}$).
Apollo lunar soil compositions benchmarked: Apollo 11, 14, 16 ($42.2\text{--}48.0\%\ \text{SiO}_2, 13.6\text{--}27.3\%\ \text{Al}_2\text{O}_3$).
Activator: 5 M $\text{NaOH}$ solution ($\text{activator}/tektite = 0.42$).
Closed-Loop Water Recovery:
Free water expelled during geopolymerization was vacuum-extracted at $-0.096\text{ MPa}$ and 60 °C.
Residual water content in hardened geopolymer gel: $< 1.5\text{ wt\%}$ of total paste mass.
Over 92 % of initial mixing water was captured and recycled into subsequent batches.
Mechanical & Extreme Environment Stability:
Compressive strength: $f_c = \mathbf{22.5\text{ MPa}}$ (Na-Si-GP) and $\mathbf{15.2\text{ MPa}}$ (Na-GP).
Thermal vacuum shock: Specimens subjected to 10 cycles of immersion in liquid nitrogen ($102.4\text{ K}$) and vacuum drying ($387.1\text{ K}$) showed zero microcracking, spalling, or compressive strength loss.
$^{29}\text{Si}$ and $^{27}\text{Al}$ MAS NMR confirmed tetrahedral $\text{Si-O-Al}$ network formation.

Linked Atlas nodes

02_concepts/strain_hardening_criteria.md
04_material_systems/geopolymer_ecc.md
04_material_systems/green_ecc.md
02_concepts/circular_economy_materials.md
02_concepts/durability.md

Relationship to Victor Li book

Extends Victor Li (2019) Chapter 4 (Matrix Microstructure) and Chapter 9 (Green ECC, pp. 307–342).
Proves a critical thermodynamic principle relevant to green ECC: unlike Portland cement hydration where water is permanently locked into fragile hydrates, geopolymerization is an inorganic catalytic process that allows complete closed-loop water recovery, enabling zero-water-loss material synthesis.

Claim-evidence rows to add

Atlas node	Claim	Evidence summary	Page/Figure/Table	Status
`02_concepts/circular_economy_materials.md`	Geopolymerization enables $> 90\%$ closed-loop water recovery under vacuum dehydration without degrading mechanical strength	Vacuum dehydration, mass loss tracking, DSC, and cube compressive testing	Section "Method" & "Results", Fig. 2-5, Table 2	verified_from_pdf
`04_material_systems/geopolymer_ecc.md`	Tektite/regolith geopolymer binders resist extreme thermal-vacuum cycling between 102.4 K and 387.1 K with zero spalling	Liquid nitrogen and vacuum chamber thermal shock cycling (10 cycles)	Section "Results and Discussion", Fig. 6	verified_from_pdf

Verification status

PDF preserved: yes (wang-2016-development-of-near-zero-water-consumption.pdf)
Text extracted: yes (full_text/wang-2016-development-of-near-zero-water-consumption_full_text.md)
DOI verified: yes (10.1038/srep29659)
Metadata verified: yes (Sci. Rep., Vol. 6, 29659, 2016)
Claim-evidence matrix ready: yes

Cautions

Tektites have higher $\text{SiO}_2$ ($~70\%$) than actual lunar regolith ($~45\%$); lunar regolith contains higher reactive $\text{Al}_2\text{O}_3$ and $\text{CaO}$, which increases geopolymerization rate.
In space or vacuum environments, fresh pastes must be cured in sealed molds to prevent premature liquid evaporation prior to polycondensation.