Optimization of Internal Patterns in 3D-Printed Walls to Control Heat Transfer and Embodied Impact

Abstract

This study presents the development and evaluation of a 3D-printable alkali-activated mortar formulated with brick masonry waste, utilized as both binder and aggregate to mitigate the environmental burden of Portland cement and reduce reliance on scarce industrial by-products. Mixtures with 50–80% recycled brick content were tested for fresh rheology, mechanical strength, thermal conductivity, and 3D-printability. Using the measured properties, finite-element thermal analyses were performed on five wall geometries with varying void configurations. The results indicate that increased void ratios substantially lower thermal transmittance, while the geometry and distribution of contact points critically influence heat transfer. The best-performing design achieved a U-value of ~4.1 W/m²K, corresponding to a 75% reduction compared to a solid wall of equal thickness. Complementary cradle-to-gate life-cycle assessment (LCA), confirmed reductions of 70–80% in embodied environmental impacts following geometric optimization. Collectively, these findings highlight the potential of integrating waste-derived geopolymer binders with optimized 3D-printed wall patterns to produce thermally efficient building envelopes. The outcomes support sustainable construction pathways and underscore the relevance of extending future research to explore multi-functional optimization (e.g., acoustic and structural performance), and the integration of passive insulation strategies to further enhance these 3D-printed systems.

Keywords

• Additive manufacturing
• Robotic 3D concrete printing
• Thermal performance
• Life-cycle assessment
• Waste management

References

1. Akduman, Ş., Kocaer, O., Aldemir, A., Şahmaran, M., Yıldırım, G., Almahmood, H., & Ashour, A. (2021). Experimental investigations on the structural behaviour of reinforced geopolymer beams produced from recycled construction materials. Journal of Building Engineering, 41, 102776. https://doi.org/10.1016/j.jobe.2021.102776
2. Aldemir, A., Akduman, S., Kocaer, O., Aktepe, R., Sahmaran, M., Yildirim, G., Almahmood, H., Ashour, A. (2022). Shear behaviour of reinforced construction and demolition waste-based geopolymer concrete beams. Journal of Building Engineering, 47, 103861. https://doi.org/10.1016/j.jobe.2021.103861
3. Alghamdi, H., & Neithalath, N. (2019). Synthesis and characterization of 3D-printable geopolymeric foams for thermally efficient building envelope materials. Cement and Concrete Composites, 104, 103377. https://doi.org/10.1016/j.cemconcomp.2019.103377
4. Alkhalidi, A., & Hatuqay, D. (2020). Energy-efficient 3D-printed buildings: Material and techniques selection worldwide study. Journal of Building Engineering, 30, 101286. https://doi.org/10.1016/j.jobe.2020.101286
5. Al-Noaimat, Y., Ghaffar, S., Chougan, M., & Al-Kheetan, M. (2023). A review of 3D printing low-carbon concrete with one-part geopolymer: Engineering, environmental and economic feasibility. Case Studies in Construction Materials, e01818. https://doi.org/10.1016/j.cscm.2022.e01818
6. Al-Yasiri, Q., & Szabó, M. (2021). Incorporation of phase change materials into building envelope for thermal comfort and energy saving: A comprehensive analysis. Journal of Building Engineering, 34, 102122. https://doi.org/10.1016/j.jobe.2020.102122
7. Assaad, J. J. (2017). Influence of recycled aggregates on dynamic/static stability of self-consolidating concrete. Journal of Sustainable Cement-Based Materials, 6, 345–365. https://doi.org/10.1080/21650373.2017.1280427
8. ASTM International. (2020). ASTM C1437-20: Standard test method for flow of hydraulic cement mortar. https://www.astm.org/c1437-15.html

9. Bai, C., Franchin, G., Elsayed, H., Zaggia, A., Conte, L., Li, H., & Colombo, P. (2017). High-porosity geopolymer foams with tailored porosity for thermal insulation and wastewater treatment. Journal of Materials Research, 32, 3251–3259. https://doi.org/10.1557/jmr.2017.127
10. Bayiha, B. N., Billong, N., Yamb, E., Kaze, R. C., & Nzengwa, R. (2019). Effect of limestone dosage on some properties of geopolymer from thermally activated halloysite. Construction and Building Materials, 217, 28–35. https://doi.org/10.1016/j.conbuildmat.2019.05.047
11. Braulio-Gonzalo, M., & Bovea, M. D. (2017). Environmental and cost performance of building envelope insulation materials to reduce energy demand: Thickness optimisation. Energy and Buildings, 150, 527–545. https://doi.org/10.1016/j.enbuild.2017.06.005
12. Carcassi, O., Maierdan, Y., Akemah, T., Kawashima, S., & Ben-Alon, L. (2024). Maximizing fiber content in 3D-printed earth materials: Printability, mechanical, thermal and environmental assessments. Construction and Building Materials. https://doi.org/10.1016/j.conbuildmat.2024.135891.
13. Chung, S. Y., Stephan, D., Abd Elrahman, M., & Han, T. S. (2016). Effects of anisotropic voids on thermal properties of insulating media investigated using 3D-printed samples. Construction and Building Materials, 111, 529–542.
14. Cuevas, K., Chougan, M., Martin, F., Ghaffar, S. H., Stephan, D., & Sikora, P. (2021). 3D-printable lightweight cementitious composites with incorporated waste-glass aggregates and expanded microspheres: Rheological, thermal and mechanical properties. Journal of Building Engineering, 44, 102718.
15. Das, A., Marchon, D., Shahsavari, R., Bos, F. P., di Luzio, G., & Scrivener, K. (2022). Effect of processing on the air void system of 3D printed concrete. Cement and Concrete Research, 156, 106789. https://doi.org/10.1016/j.cemconres.2022.106789
16. Déspeisse, M., Baumers, M., Brown, P., Charnley, F., Ford, S., Garmulewicz, A., … Rowley, J. (2017). Unlocking value for a circular economy through 3D printing: A research agenda. Technological Forecasting and Social Change, 115, 75–84. https://doi.org/10.1016/j.techfore.2016.09.021
17. Du Plessis, A., Broeckhoven, C., Yadroitsava, I., Yadroitsev, I., Hands, C. H., Kunju, R., & Bhate, D. (2019). Beautiful and functional: A review of biomimetic design in additive manufacturing. Additive Manufacturing, 27, 408–427.
18. Dwivedi, E. (2024). A review on development of 3D printable concrete by utilizing agro-industrial waste: Evaluation of fresh properties. International Journal for Research in Applied Science and Engineering Technology, 12(6). https://doi.org/10.22214/ijraset.2024.63530
19. EN ISO 6946. (2017). Building components and building elements—Thermal resistance and thermal transmittance—Calculation methods (3rd ed.). International Organization for Standardization.
20. Falliano, D., De Domenico, D., Ricciardi, G., & Gugliandolo, E. (2020). 3D-printable lightweight foamed concrete and comparison with classical foamed concrete in terms of fresh-state properties and mechanical strength. Construction and Building Materials, 254, 119271.
21. Feng, C., & Yu, S. (2021). 3D printing of thermal insulating polyimide/cellulose nanocrystal composite aerogels with low dimensional shrinkage. Polymers, 13, 3614. https://doi.org/10.3390/polym13213614
22. Feng, J., Zhang, R., Gong, L., Li, Y., Cao, W., & Cheng, X. (2015). Development of porous fly ash-based geopolymer with low thermal conductivity. Materials & Design, 65, 529–533.
23. Galadanci, A., Ianakiev, A., Kromanis, R., & Robinson, J. (2020). Energy investigation framework: Understanding buildings from an energy perspective view. Journal of Building Engineering, 28, 101046. https://doi.org/10.1016/j.jobe.2019.101046
24. Gokce, H. S., Gungor, O., & Oksuzer, N. (2022). A novel internal curing method for 3D-printed geopolymer structures reinforced with a steel cable: Electro-heating. Materials Letters, 309, 131364. https://doi.org/10.1016/j.matlet.2021.131364
25. Huang, H., Zhou, Y., Huang, R., Wu, H., Sun, Y., Huang, G., & Xu, T. (2020). Optimum insulation thicknesses and energy conservation of building thermal insulation materials in the humid subtropical zone of China. Sustainable Cities and Society, 52, 101840. https://doi.org/10.1016/j.scs.2019.101840
26. Huang, Y., Gong, L., Pan, Y., Li, C., Zhou, T., & Cheng, X. (2018). Facile construction of an aerogel/geopolymer composite with ultra-low thermal conductivity and high mechanical performance. RSC Advances, 8, 2350–2356.
27. Huiskes, D. M. A., Keulen, A., Yu, Q. L., & Brouwers, H. J. H. (2016). Design and performance evaluation of ultra-lightweight geopolymer concrete. Materials & Design, 89, 516–526.
28. Hussein, M., Monna, S., Abdallah, R., Juaidi, A., Albatayneh, A. (2022). Improving the thermal performance of building envelopes: An approach to enhancing the building energy efficiency code. Sustainability, 14, 16264. https://doi.org/10.3390/su142316264
29. Irshidat, M., Cabibihan, J. J., Fadli, F., Al-Ramahi, S., & Saadeh, M. (2025). Waste materials utilization in 3D-printable concrete for sustainable construction applications: A review. Emergent Materials, 8(3), 1357–1379. https://doi.org/10.1007/s42247-024-00942-4
30. ISO. (2006a). Environmental management—Life cycle assessment—Principles and framework (ISO 14040). International Organization for Standardization.
31. ISO. (2006b). Environmental management—Life cycle assessment—Requirements and guidelines (ISO 14044). International Organization for Standardization.
32. Jaya, N., Yun-Ming, L., Cheng-Yong, H., Abdullah, M., & Hussin, K. (2020). Correlation between pore structure, compressive strength and thermal conductivity of porous metakaolin geopolymer. Construction and Building Materials, 247, 118641. https://doi.org/10.1016/j.conbuildmat.2020.118641.
33. Kam, D., Layani, M., Barkai-Minerbi, S., Orbaum, D., Ben-Harush, S., Shoseyov, O., & Magdassi, S. (2019). Additive manufacturing of 3D structures composed of wood materials. Advanced Materials Technologies, 4, 1900158. https://doi.org/10.1002/admt.201900158
34. Kanagaraj, B., Anand, N., Raj, R. S., & Lublóy, E. (2023). Techno-socio-economic aspects of Portland cement, geopolymer, and limestone calcined clay cement (LC3) composite systems: A state-of-the-art review. Construction and Building Materials, 398, 132484. https://doi.org/10.1016/j.conbuildmat.2023.132484
35. Kocaer, O., & Aldemir, A. (2023). Compressive stress–strain model for the estimation of the flexural capacity of reinforced geopolymer concrete members. Structural Concrete, 24(4), 5102–5121. https://doi.org/10.1002/suco.202200914
36. Kocaer, O., & Aldemir, A. (2025). Confined compressive stress–strain model for rectangular geopolymer reinforced concrete members. Structural Concrete, 26(4), 4334–4347. https://doi.org/10.1002/suco.202300973
37. Kul, A., Kocaer, O., Aldemir, A., Yildirim, G., & Lucas, S. S. (2024a). 3D-printable one-part alkali-activated mortar derived from brick masonry wastes. Case Studies in Construction Materials, e04081. https://doi.org/10.1016/j.cscm.2024.e04081
38. Kul, A., Ozcelikci, E., Ozel, B. F., Gunal, M. F., Yildirim, G., Bayer, I. R., & Demir, I. (2024b). Evaluation of mechanical and microstructural properties of engineered geopolymer composites with construction-and-demolition-waste-based matrices. Journal of Materials in Civil Engineering, 36(1), 04023524. https://doi.org/10.1061/JMCEE7.MTENG-15918
39. Lee, J., Kim, J., Song, D., Kim, J., & Jang, C. (2017). Impact of external insulation and internal thermal density on building energy consumption in a temperate climate with four distinct seasons. Renewable and Sustainable Energy Reviews, 75, 1081–1088. https://doi.org/10.1016/j.rser.2016.11.087
40. Lin, Y., Tsai, K., Lin, M., & Yang, M. (2016). Design optimization of office building envelope configurations for energy conservation. Applied Energy, 171, 336–346. https://doi.org/10.1016/j.apenergy.2016.03.018
41. Liu, M. Y. J., Alengaram, U. J., Jumaat, M. Z., & Mo, K. H. (2014). Evaluation of thermal conductivity, mechanical and transport properties of lightweight aggregate foamed geopolymer concrete. Energy and Buildings, 72, 238–245. https://doi.org/10.1016/j.enbuild.2013.12.029
42. Liu, R., & Du, H. (2025). Optimizing thermal insulation through geometric design: Comparative analysis of normal and lightweight 3D-printed concrete wall patterns. Energy and Buildings, 116437. https://doi.org/10.1016/j.enbuild.2024.116437
43. Liu, X., Wu, J., Zhao, X., Yan, P., & Ji, W. (2021). Effect of brick waste content on mechanical properties of mixed recycled concrete. Construction and Building Materials, 288, 123320. https://doi.org/10.1016/j.conbuildmat.2021.123320
44. Long, L. (2023). An AI-driven model for predicting and optimizing energy-efficient building envelopes. Alexandria Engineering Journal, 81, 203–214. https://doi.org/10.1016/j.aej.2023.08.041
45. Long, W. J., Lin, C., Tao, J. L., Ye, T. H., & Fang, Y. (2021). Printability and particle packing of 3D-printable limestone calcined clay cement composites. Construction and Building Materials, 282, 122647. https://doi.org/10.1016/j.conbuildmat.2021.122647
46. Mansouri, A., Binali, A., Aljawi, A., Alhammadi, A., Almir, K., Alnuaimi, E., & Rodriguez-Ubinas, E. (2022). Thermal modeling of the convective heat transfer in the large air cavities of 3D concrete-printed walls. Cogent Engineering, 9(1), 2130203. https://doi.org/10.1080/23311916.2022.2130203
47. Medri, V., Papa, E., Mazzocchi, M., Laghi, L., Morganti, M., Francisconi, J., & Landi, E. (2015). Production and characterization of lightweight vermiculite/geopolymer-based panels. Materials & Design, 85, 266–274. https://doi.org/10.1016/j.matdes.2015.06.145
48. Murray, H. H. (2000). Traditional and new applications for kaolin, smectite, and palygorskite: A general overview. Applied Clay Science, 17(5–6), 207–221. https://doi.org/10.1016/S0169-1317(00)00016-8
49. Mutel, C. (2017). Brightway: An open source framework for life cycle assessment. Journal of Open Source Software, 2(12), 236. https://doi.org/10.21105/joss.00236
50. Najafi, E., & Khanbilvardi, R. (2019). Evaluating global crop distribution in the 21st century to maximize food production. In AGU Fall Meeting Abstracts, B31F-2440 (December).
51. O’Hegarty, R., Kinnane, O., Lennon, D., & Colclough, S. (2021). In-situ U-value monitoring of highly insulated building envelopes: Review and experimental investigation. Energy and Buildings, 253, 111447. https://doi.org/10.1016/j.enbuild.2021.111447
52. Padmini, A. K., Ramamurthy, K., & Mathews, M. S. (2002). Relative moisture movement through recycled-aggregate concrete. Magazine of Concrete Research, 54(5), 377–384. https://doi.org/10.1680/macr.2002.54.5.377
53. Panda, B., Leite, M., Biswal, B., Niu, X., & Garg, A. (2018). Experimental and numerical modelling of mechanical properties of 3D-printed honeycomb structures. Measurement, 116, 495–506. https://doi.org/10.1016/j.measurement.2017.11.037
54. Peng, Y., & Unluer, C. (2022). Development of alternative cementitious binders for 3D printing applications: A critical review of progress, advantages and challenges. Composites Part B: Engineering, 245, 110492. https://doi.org/10.1016/j.compositesb.2022.110492
55. Pérez-Lombard, L., Ortiz, J., & Pout, C. (2008). A review on buildings’ energy consumption information. Energy and Buildings, 40(3), 394–398. https://doi.org/10.1016/j.enbuild.2007.03.007
56. Qi, B., Xu, P., & Wu, C. (2023). Analysis of the infiltration and water-storage performance of recycled brick mix aggregates in sponge-city construction. Water, 15(2), 363. https://doi.org/10.3390/w15020363
57. Rathinavel, N., Aleem, A., & Ismail, M. (2025). Energy-Efficient geopolymer wall panels: optimizing mechanical, thermal, and acoustic properties for sustainable construction. Scientific Reports, 15. https://doi.org/10.1038/s41598-025-11783-4.
58. Schiavoni, S., D’Alessandro, F., Bianchi, F., & Asdrubali, F. (2016). Insulation materials for the building sector: A review and comparative analysis. Renewable and Sustainable Energy Reviews, 62, 988–1011. https://doi.org/10.1016/j.rser.2016.05.045
59. Simpeh, E., Pillay, J., Ndihokubwayo, R., & Nalumu, D. (2021). Improving energy efficiency of HVAC systems in buildings: A review of best practices. International Journal of Building Pathology and Adaptation. https://doi.org/10.1108/ijbpa-02-2021-0019.
60. Suntharalingam, T., Upasiri, I., Gatheeshgar, P., Poologanathan, K., Nagaratnam, B., Santos, P., & Rajanayagam, H. (2021). Energy performance of 3D-printed concrete walls: A numerical study. Buildings, 11(10), 432. https://doi.org/10.3390/buildings11100432
61. Türkel, İ., Özkan, İ. G. M., Baltaoğlu, E., Benli, A., Bayraktar, O. Y., … Kaplan, G. (2025). Enhancing thermal insulation, mechanical strength, and durability of one-part fly ash-based geopolymer foam concrete using lime and mahogany sawdust. Construction and Building Materials, 491, 142656. https://doi.org/10.1016/j.conbuildmat.2025.142656
62. United Nations. (2019). World population prospects 2019. Department of Economic and Social Affairs.
63. Verbeke, S., & Audenaert, A. (2018). Thermal inertia in buildings: A review of impacts across climate and building use. Renewable and Sustainable Energy Reviews, 82, 2300–2318. https://doi.org/10.1016/j.rser.2017.08.083
64. Wong, L. S. (2022). Durability performance of geopolymer concrete: A review. Polymers, 14(5), 868. https://doi.org/10.3390/polym14050868
65. Wu, H., Gao, J., Liu, C., Guo, Z., & Luo, X. (2024). Reusing waste clay brick powder for low-carbon cement concrete and alkali-activated concrete: A critical review. Journal of Cleaner Production, 451, 141755. https://doi.org/10.1016/j.jclepro.2024.141755
66. Zenabou, N., Benoit-Ali, N., Zekeng, S., Rossignol, S., Melo, U., Tchamba, A., Kamseu, E., & Leonelli, C. (2019). Improving insulation in metakaolin based geopolymer: Effects of metabauxite and metatalc. Journal of Building Engineering. https://doi.org/10.1016/j.jobe.2019.01.012.
67. Zeyad, A. M., Bayraktar, O. Y., Tayeh, B. A., Öz, A., Özkan, İ. G. M., & Kaplan, G. (2024). Impact of rice husk ash on physico-mechanical, durability and microstructural features of rubberized lightweight geopolymer composite. Construction and Building Materials, 427, 136265. https://doi.org/10.1016/j.conbuildmat.2024.136265
68. Zhang, C., Nerella, V. N., Krishna, A., Wang, S., Zhang, Y., Mechtcherine, V., & Banthia, N. (2021). Mix design concepts for 3D printable concrete: A review. Cement and Concrete Composites, 122, 104155. https://doi.org/10.1016/j.cemconcomp.2021.104155
69. Zhang, Z., Provis, J. L., Reid, A., & Wang, H. (2015). Mechanical, thermal insulation, thermal resistance and acoustic absorption properties of geopolymer foam concrete. Cement and Concrete Composites, 62, 97–105. https://doi.org/10.1016/j.cemconcomp.2015.03.013