Sustainable Lightweight Concrete Using Candlenut Shell as Coarse Aggregate: The Impact of Water-Cement Ratios on Strength and Density

  • Reza Hasrul Department of Civil Engineering and Planning Education, Makassar State University, Makassar, INDONESIA and Graduate School of Environmental, Life, Natural Science and Technology, Okayama University, JAPAN
  • Mohammad Junaedy Rahman Department of Civil Engineering and Planning Education, Makassar State University, Makassar, INDONESIA
  • Ahnaf Riyandirga Ariyansyah Putra Helmy Department of Civil Engineering and Planning Education, Makassar State University, Makassar, INDONESIA
  • Taufiq Natsir Department of Civil Engineering and Planning Education, Makassar State University, Makassar, INDONESIA
  • Ahmad Rifqi Asrib Department Population and Environmental Education, Graduate School Makassar State University, Makassar, INDONESIA
DOI: https://doi.org/10.22146/jcef.18175
Keywords: Lightweight concrete, Candlenut shell aggregate, Water-cement ratio, Sustainable construction, Agricultural waste

Abstract

This study explores the promising potential of Candlenut Shell Aggregate (CSA) as a sustainable and innovative alternative for lightweight concrete production. Derived from Aleurites moluccanus, CSA is an agricultural by-product characterized by its low density, moderate abrasion resistance, and high water absorption make it suitable for non-structural applications like wall panels and flooring. However, integrating CSA into concrete mixes requires careful management of the water-cement (w/c) ratio which significantly affects compressive strength, density, and workability. Concrete mixes were prepared using the absolute volume method, with w/c ratios ranging from 0.65 to 0.30, to identify the optimal balance. The absolute volume principle was applied for all mix designs. Our results indicate that an optimal w/c ratio of 0.55 yields the most favorable balance, achieving the highest compressive strength of 14.3 MPa and a maximum density of approximately 1850 kg/m3. This specific ratio strikes an ideal equilibrium between adequate cement hydration and effective void minimization within the concrete matrix. Conversely, higher w/c ratios lead to increased porosity, diminishing both strength and density, while lower ratios impair workability, hindering compaction and hydration, ultimately degrading performance. These findings resonate strongly with existing prior research, further emphasizing the crucial need for pre-treatment of CSA, such as soaking or the strategic incorporation of admixtures, to effectively mitigate its inherent high absorption and enhance overall mix performance. In conclusion, this study robustly confirms the feasibility of utilizing CSA as a lightweight aggregate. This represents a significant step towards developing an eco-friendly solution that not only contributes to global sustainability goals by repurposing agricultural waste but also actively reduces reliance on conventional, resource-intensive aggregates. Future research should explore the long-term durability of CSA-based concrete and investigate advanced admixtures to further enhance its properties for broader applications.

References

Abdelgader, S. H., Kurpinska, M., Abdelgader, H. S., Omidi Moaf, F., & Amran, M. (2024). ‘Study the impact of design method preference on the usefulness of concrete and on CO₂ emissions’. International Journal of Building Pathology and Adaptation. URL: https://doi.org/10.1108/IJBPA-12-2023-0185

Aboul-Nour, L., Zaghlal, M., & Malek, K. (2020). ‘Improving compressive strength of lightweight aggregate concrete’. The Egyptian International Journal of Engineering Sciences and Technology, 30(1), 12–21. URL: https://doi.org/10.21608/eijest.2020.104929

Alengaram, U. J., Muhit, B. A. A., & Jumaat, M. Z. B. (2013). ‘Utilization of oil palm kernel shell as lightweight aggregate in concrete – a review’. Construction and Building Materials, 38, 161–172. URL: https://doi.org/10.1016/j.conbuildmat.2012.08.026

Alqahtani, F. K., & Zafar, I. (2023). ‘Exploring the effect of different waste fillers in manufactured sustainable plastic aggregates matrix on the structural lightweight green concrete’. Sustainability, 15(3), 2311. URL: https://doi.org/10.3390/su15032311

Carette, G., & Malhotra, V. (1983). ‘Mechanical properties, durability, and drying shrinkage of portland cement concrete incorporating silica fume’. Cement, Concrete, and Aggregates, 5(1), 3–13. URL: https://doi.org/10.1520/CCA10244J

Chandra, S., & Berntsson, L. (2002). Lightweight Aggregate Concrete: Science, Technology, and Applications. Noyes Publications: William Andrew Pub. URL: https://www.worldcat.org/title/49895577

Chindaprasirt, P., Homwuttiwong, S., & Jaturapitakkul, C. (2007). ‘Strength and water permeability of concrete containing palm oil fuel ash and rice husk–bark ash’. Construction and Building Materials, 21(7), 1492–1499. URL: https://doi.org/10.1016/j.conbuildmat.2006.06.015

Cui, Y., Wang, L., Liu, J., Liu, R., & Pang, B. (2022). ‘Impact of particle size of fly ash on the early compressive strength of concrete: Experimental investigation and modelling’. Construction and Building Materials, 323, 126444. URL: https://doi.org/10.1016/j.conbuildmat.2022.126444

Daryono, L. R., Aoki, S., Kano, M., Miyanaga, M., Nakashima, K., & Kawasaki, S. (2023). ‘Biomineralization grouting for beach sand cemented with MICP’. Journal of the Civil Engineering Forum, 31–38. URL: https://doi.org/10.22146/jcef.6454

Feldman, R. F., & Sereda, P. J. (1970). ‘Written discussion of “Structures and physical properties of cement paste” by George J. Verbeck and Richard H. Helmuth (Portland Cement Association, Skokie, Ill, U.S.A.)’. Cement and Concrete Research, 3, 36–44.

Hilal, N., Hamah Sor, N., Hadzima-Nyarko, M., Radu, D., & Tawfik, T. A. (2024). ‘The influence of nanosunflower ash and nanowalnut shell ash on sustainable lightweight self-compacting concrete characteristics’. Scientific Reports, 14(1), 9450. URL: https://doi.org/10.1038/s41598-024-60096-5

Hussein, Y. M., Elrahman, M. A., Elsakhawy, Y., Tayeh, B. A., & Tahwia, A. M. (2022). ‘Development and performance of sustainable structural lightweight concrete containing waste clay bricks’. Journal of Materials Research and Technology, 21, 4344–4359. URL: https://doi.org/10.1016/j.jmrt.2022.11.042

Jamwal, A., Nautiyal, A., Singh, K., Alam, S., Alselami, N. A., & Aati, K. M. (2024). ‘Sustainable concrete production: Utilizing cow dung ash and corn stalk ash as eco-friendly alternatives’. Civil Engineering Journal, 10, 21–36. URL: https://doi.org/10.28991/CEJ-SP2024-010-02

Karimi, H. R., Ebneabbasi, P., Shahni Karamzadeh, N., & Khedri, E. (2023). ‘Effect of water to cement (w/c) ratio and age on mechanical behavior of tire–recycled steel fiber reinforced concrete’. Structural Concrete, 24(2), 2460–2474. URL: https://doi.org/10.1002/suco.202200007

Mannan, M. A., & Ganapathy, C. (2004). ‘Concrete from an agricultural waste-oil palm shell (OPS)’. Building and Environment, 39(4), 441–448. URL: https://doi.org/10.1016/j.buildenv.2003.10.007

Mindess, S., Young, J. F., & Darwin, D. (2003). Concrete (2nd ed.). Prentice Hall.

Natarajan, K. S., Ramalingasekar, D., Palanisamy, S., & Ashokan, M. (2022). ‘Effect on mechanical properties of lightweight sustainable concrete with the use of waste coconut shell as replacement for coarse aggregate’. Environmental Science and Pollution Research, 29(26), 39421–39426. URL: https://doi.org/10.1007/s11356-022-18905-9

Navaratnam, S., Tushar, Q., Jahan, I., & Zhang, G. (2023). ‘Environmental sustainability of industrial waste-based cementitious materials: A review, experimental investigation and life-cycle assessment’. Sustainability, 15(3), 1873. URL: https://doi.org/10.3390/su15031873

Nawy, E. G. (Ed.). (2008). Concrete Construction Engineering Handbook (2nd ed.). CRC Press.

Neville, A. M., & Brooks, J. J. (2010). Concrete Technology (2nd ed.). Prentice Hall.

Ortega, J. M., Branco, F. G., & Pereira, L. (2023). ‘Long-term behavior related to water ingress in mortars which combine expanded and natural cork lightweight aggregates and eco-friendly cements’. Buildings, 13(7), 1651. URL: https://doi.org/10.3390/buildings13071651

Patah, D., Dasar, A., & Noor, N. M. (2025). ‘The effects of palm oil fuel ash on mechanical and durability properties of sustainable foamed concrete’. Journal of the Civil Engineering Forum, 75–84. URL: https://doi.org/10.22146/jcef.13749

Prakash, R., Thenmozhi, R., Raman, S. N., Subramanian, C., and Divyah, N. (2021), ‘Mechanical characterisation of sustainable fibre-reinforced lightweight concrete incorporating waste coconut shell as coarse aggregate and sisal fibre’, International Journal of Environmental Science and Technology, 18(6), 1579–1590. URL: https://doi.org/10.1007/s13762-020-02900-z

Putra, S. A., Ary Wahyudie, I., and Darta, Y. (2023), ‘Pengaruh ukuran butir pasir terhadap kuat tekan cellular lightweight concrete’, Jurnal Inovasi Teknologi Terapan, 1(2), 428–433. URL: https://doi.org/10.33504/jitt.v1i2.88

Rahman, M. J., Hasrul, M. R., Ashad, H., Yusuf, F. A., and Hasrul, N. R. (2024), ‘An assessment of derelict building constructions situated in coastal regions’, Journal of the Civil Engineering Forum, 10(3), 229–238. URL: https://doi.org/10.22146/jcef.10433

Shafigh, P., Jumaat, M. Z., and Mahmud, H. (2011), ‘Oil palm shell as a lightweight aggregate for production high strength lightweight concrete’, Construction and Building Materials, 25(4), 1848–1853. URL: https://doi.org/10.1016/j.conbuildmat.2010.11.075

Sikora, P., Afsar, L., Rathnarajan, S., Nikravan, M., Chung, S.-Y., Stephan, D., and Abd Elrahman, M. (2023), ‘Seawater-mixed lightweight aggregate concretes with dune sand, waste glass and nanosilica: Experimental and life cycle analysis’, International Journal of Concrete Structures and Materials, 17(1), 47. URL: https://doi.org/10.1186/s40069-023-00613-4

Sivakumar, A., and Santhanam, M. (2007), ‘A quantitative study on the plastic shrinkage cracking in high strength hybrid fibre reinforced concrete’, Cement and Concrete Composites, 29(7), 575–581. URL: https://doi.org/10.1016/j.cemconcomp.2007.03.005

Published
2025-07-17
How to Cite
Hasrul, R., Rahman, M. J., Helmy, A. R. A. P., Natsir, T., & Asrib, A. R. (2025). Sustainable Lightweight Concrete Using Candlenut Shell as Coarse Aggregate: The Impact of Water-Cement Ratios on Strength and Density. Journal of the Civil Engineering Forum, 11(3), 257-266. https://doi.org/10.22146/jcef.18175
Issue
Vol. 11 No. 3 (September 2025)
Section
Articles

Copyright (c) 2025 The Author(s)

Creative Commons License

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Copyright is granted to authors for the purpose of providing protection for articles written to describe experiments and their results. JCEF will protect and defend the work and reputation of the author and are also willing to address any allegations of violation, plagiarism, fraud, etc. against articles written and published by JCEF.  JCEF is published under the terms of the Creative Commons Attribution-ShareAlike 4.0 International License (CC BY-SA 4.0). The author holds the copyright and assigns the journal rights to the first publication (online and print) of the work simultaneously.