Laboratory testing on cracking characteristics and improvement mechanism of coral mud

Abstract

In recent years, the development and construction of island reefs have been flourishing. Due to the remoteness of island reefs from the mainland, the scarcity of building materials, and the high transportation costs, it is imperative to use local marine resources, and the potential value and status of coral mud on island reefs, which is formed by the remains of corals and other biological entities, is becoming increasingly prominent. Utilization and optimization of natural resources on island reefs have become a brand-new research direction and challenge. This article mainly focuses on the development of a new type of green engineering material, coral mud, for use in building surface layers. Thickness effects, PVA fiber (vinylon staple fiber) modification, and HPMC (Hydroxypropyl Methyl Cellulose) adhesive modification are taken into consideration. Through laboratory tests and image processing technology, fractal theory, and electron microscopy experiments, the macro-meso-microscopic multi-scale cracking rules of the coral mud surface layer and the optimization modification rules of PVA fibers and HPMC adhesives are revealed. The results demonstrate that the performance of the coral mud surface layer is superior to that of the kaolin surface layer, and the 10 mm thickness performs better than the 5 mm and 20 mm thicknesses. As the thickness of the coral mud surface layer increases, the contact between coral mud particles becomes denser, the scale of surface micro-cracks decreases, and the number of micro-pores decreases. PVA fibers can effectively inhibit the further development of macro and micro cracks and play a good bridging role. There is a bonding and adhesion relationship between coral mud and PVA fibers, and they have a good synergistic effect in inhibiting macro and mesoscopic cracks. With the increase in HPMC adhesive content, the number of micro-cracks and the scale of micro-cracks decrease accordingly, and the structure and performance of the coral mud surface layer are further improved. Overall, PVA fibers are more effective than HPMC adhesives in inhibiting the cracking of the coral mud surface layer. This provides valuable guidance for the development and application of coral mud in wall surface materials.

Keywords

Coral Mud Surface Layer / Multi-scale cracks / PVA Fiber / HPMC Adhesive / Optimization Utilization

CRediT authorship contribution statement

Huaqiang Fang: Writing - review & editing, Writing - original draft, Visualization, Validation, Methodology, Investigation, Formal analysis, Data curation, Conceptualization. Xuanming Ding: Writing - review & editing, Supervision, Resources, Project administration, Methodology, Investigation, Funding acquisition, Formal analysis, Conceptualization. Yifu Li: Writing - review & editing, Validation, Methodology, Investigation. Hong Wang: Writing - review & editing, Validation, Methodology, Investigation. Junyu Ren: Writing - review & editing, Validation, Methodology, Investigation.

Declaration of Competing Interest

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Acknowledgements

This work is supported by the Fundamental Research Funds for the Central Universities (Grant Nos.2022CDJQY-012).

References

[1] Chen, X. S., Ding, X. M., Jiang, C. Y., Fang, H. Q., & Wang, C. L. (2020). Experimental study on permeability characteristics of hydraulic reclamation calcareous clay in coral reef island(in Chinese). Journal of Civil and Environmental Engineering, 1-9.

[2] Ding, X. M., Luo, Z. G., & Ou, Q. (2022). Mechanical property and deformation behavior of geogrid reinforced calcareous sand. Geotextiles and Geomembranes, 50(4), 618-631. https://doi.org/10.1016/j.geotexmem.2022.03.002

[3] Ding, X. M., Deng, X., Ou, Q., & Deng, W. T. (2023a). Experimental study on the behavior of single pile foundation under vertical cyclic load in coral sand. Ocean Engineering, 280, Article 114672. https://doi.org/10.1016/j.oceaneng.2023.114672

[4] Ding, X. M., Zhao, J. Q., Hu, J., & Ou, Q. (2023c). In situ experiment on velocity response induced by vibroflotation in calcareous sand foundation. Journal of Testing Evaluation, 51(6), https://doi.org/10.1520/JTE20220553

[5] Ding, X. M., Deng, W. T., Peng, Y., Zhou, H., & Wang, C. Y. (2021). Bearing behavior of cast-in-place expansive concrete pile in coral sand under vertical loading. China Ocean Engineering, 35(3), 352-360. https://doi.org/10.1007/S13344-021-0038-8

[6] Ding, X. M., Fang, H. Q., Liu, H. L., Jiang, C. Y., & Li, G. F. (2023b). Dynamic evolution laws of desiccation cracking of fiber-improved coral silt(in Chinese). Chinese Journal of Geotechnical Engineering.

[7] Fang, H. Q., Jiang, C. Y., Wang, C. L., Ou, Q., & Long, K. Q. (2021). Effects of layer thickness and temperature on the crack morphology of Chongqing silt(in Chinese). Chinese Journal of Rock Mechanics and Engineering, 40(12), 2570-2583. https://doi.org/10.13722/j.cnki.jrme.2021.0313

[8] Fang, H. Q., Ding, X. M., Jiang, C. Y., Peng, Y., & Wang, C. Y. (2022). Effects of layer thickness and temperature on desiccation cracking characteristics of coral clay. Bulletin of Engineering Geology and the Environment, 81(9), https://doi.org/10.1007/s10064-022-02884-9

[9] Gao, R., & Ye, J. H. (2023). Mechanical behaviors of coral sand and relationship between particle breakage and plastic work. Engineering Geology, 316, Article 107063. https://doi.org/10.1016/j.enggeo.2023.107063

[10] He, S. H., Shan, H. F., Xia, T. D., Liu, Z. J., Ding, Z., & Xia, F. (2021). The effect of temperature on the drained shear behavior of calcareous sand. Acta Geotechnica, 16, 613-633. https://doi.org/10.1007/s11440-020-01030-7

[11] Jiang, C. Y., Ding, X. M., Chen, X. S., Fang, H. Q., & Zhang, Y. (2022). Laboratory study on geotechnical characteristics of marine coral clay. Journal of Central South University, 29(02), 572-581. https://doi.org/10.1007/s11771-022-4900-5

[12] Lei, X. W., Ding, H., Wang, X. Z., Shen, J. H., & Meng, Q. S. (2021). Experimental study of consolidation properties of calcareous silt(in Chinese). Rock and Soil Mechanics, 42(04), 909-920. https://doi.org/10.16285/j.rsm.2020.0993

[13] Li, Y. J., Guo, Z., Yang, Z. Q., Li, Y. L., & Xu, M. T. (2023). Experimental study on the reaction process and engineering characteristics of marine calcareous sand reinforced by eco-friendly methods. Applied Ocean Research, 138, Article 103641. https://doi.org/10.1016/j.apor.2023.103641

[14] Lin, Z. Y., Tang, C. S., Yang, Z. M., Wang, Y. S., Cheng, Q., & Shi, B. (2022). Modeling of drying-induced soil curling phenomenon. Water Resources Research, 58(1), https://doi.org/10.1029/2021WR029749

[15] Liu, C., Tang, C. S., Shi, B., & Suo, W. B. (2013). Automatic quantification of crack patterns by image processing. Computers & Geosciences, 57, 77-80. https://doi.org/10.1016/j.cageo.2013.04.008

[16] Liu, L., Liu, H. L., Stuedlein, A., Evans, T., & Xiao, Y. (2019). Strength, stiffness, and microstructure characteristics of biocemented calcareous sand. Canadian Geotechnical Journal, 56, 1502-1513. https://doi.org/10.1139/cgj-2018-0007

[17] Ma, C. H., Zhu, C. Q., Qu, R., Liu, H. F., & Wang, T. M. (2023). Influence of the particle morphology and internal porosity characteristics of coral sand in the South China Sea on its limit void ratio. Powder Technology, 428, Article 118771. https://doi.org/10.1016/j.powtec.2023.118771

[18] Peng, Y., Ding, X., Xiao, Y., Deng, X., & Deng, W. (2019). Detailed amount of particle breakage in nonuniformly graded sands under one-dimensional compression. Canadian Geotechnical Journal, 57(8), 1239-1246. https://doi.org/10.1139/cgj-2019-0283

[19] Peng, Y., Liu, H. L., Li, C., Ding, X. M., Deng, X., & Wang, C. Y. (2021). The detailed particle breakage around the pile in coral sand. Acta Geotechnica, 16(6), 1971-1981. https://doi.org/10.1007/s11440-020-01089-2

[20] Qin, Z. G. (2022). Engineering properties of coral reef soft-soil(in Chinese). 232-238+244 Port & Waterway Engineering, 603(12), https://doi.org/10.16233/j.cnki.issn1002-4972.20221129.028

[21] Rui, S. J., Guo, Z., Si, T. L., & Li, Y. J. (2020). Effect of particle shape on the liquefaction resistance of calcareous sands. Soil Dynamics and Earthquake Engineering, 137, Article 106302. https://doi.org/10.1016/j.soildyn.2020.106302

[22] Shahnazari, H., & Rezvani, R. (2013). Effective parameters for the particle breakage of calcareous sands: An experimental study. Engineering Geology, 159, 98-105. https://doi.org/10.1016/j.enggeo.2013.03.005

[23] Shen, Y., Feng, Z. Y., Liu, H. L., Wang, Q. C., & An, L. (2018). Experimental study on effects of initial concentration on settling velocity characteristics of turbid surface of South China Sea coral mud(in Chinese). Chinese Journal of Geotechnical Engineering, 40(S2), 22-26.

[24] Tang, C. S., Li, H., Pan, X. H., Yin, L. Y., Cheng, L., Cheng, Q., Liu, B., & Shi, B. (2022). Coupling effect of biocementation-fiber reinforcement on mechanical behavior of calcareous sand for ocean engineering. Bulletin of Engineering Geology and the Environment, 81(4), https://doi.org/10.1007/s10064-022-02662-7

[25] Tran, K. M., Bui, H. H., Kodikara, J., & Sánchez, M. (2020). Soil curling process and its influencing factors. Canadian Geotechnical Journal, 57(3), 408-422. https://doi.org/10.1139/cgj-2018-0489

[26] Wang, C., Liu, H., Ding, X., Wang, C., & Ou, Q. (2021a). Study on horizontal bearing characteristics of pile foundations in coral sand. Canadian Geotechnical Journal, 99(999), 1928-1942. https://doi.org/10.1139/cgj-2020-0623

[27] Wang, D. L., Tang, C. S., Pan, X. H., Liu, B., & Shi, B. (2023). Coupling effect of fiber reinforcement and MICP stabilization on the tensile behavior of calcareous sand. Engineering Geology, 317, Article 107090. https://doi.org/10.1016/j.enggeo.2023.107090

[28] Wang, J. Z., Ding, X. M., Jiang, C. Y., & Fang, H. Q. (2021b). Laboratory tests on vacuum preloading and electro-osmotic consolidation of calcareous soft soil(in Chinese). Chinese Journal of Geotechnical Engineering, 43(S2), 36-40.

[29] Wang, L., Jiang, X., Xiao, Y., Wu, H. R., Shan, J. J., Liu, H. L., & Yao, Z. H. (2021c). Experimental research on size effect and avalanche dynamics characteristics of calcareous sand particles. Chinese Journal of Geotechnical Engineering, 43(6), 1029-1038.

[30] Wang, X. Z., Jiao, Y. Y., Wang, R., Hu, M. J., Meng, Q. S., & Tan, F. Y. (2011). Engineering characteristics of the calcareous sand in Nansha Islands, South China Sea. Engineering geology, 120(1-4), 40-47. https://doi.org/10.1016/j.enggeo.2011.03.011

[31] Wang, X. Z., Wang, X., Hu, M. J., Zhu, C. Q., Meng, Q. S., & Wang, R. (2017a). Study of permeability of calcareous silty layer of foundation at an artificial reclamation island (in Chinese). Rock and Soil Mechanics, 38(11), 3127-3135. https://doi.org/10.16285/j.rsm.2017.11.007

[32] Wang, X. Z., Wang, X., Jin, Z. C., Meng, Q. S., Zhu, C. Q., & Wang, R. (2017b). Shear characteristics of calcareous gravelly soil. Bulletin of Engineering Geology the Environment, 76, 561-573. https://doi.org/10.1007/s10064-016-0978-z

[33] Wang, X. Z., Wang, X., Chen, J. W., Wang, R., Hu, M. J., & Meng, Q. S. (2018). Experimental study on permeability characteristics of calcareous soil. Bulletin of Engineering Geology and the Environment, 77, 1753-1762. https://doi.org/10.1007/s10064-017-1104-6

[34] Wu, Q., Ding, X., Chen, Z., & Zhang, Y. (2022). Shaking table tests on seismic responses of pile-soil-superstructure in coral sand. Journal of Earthquake Engineering, 26(7), 3461-3487. https://doi.org/10.1080/13632469.2020.1803160

[35] Xiao, R., Liang, B. Y., Wu, F., Huang, L. C., & Lai, Z. S. (2023a). Biocementation of coral sand under seawater environment and an improved three-stage biogrouting approach. Construction and Building Materials, 362, Article 129758. https://doi.org/10.1016/j.conbuildmat.2022.129758

[36] Xiao, Y., Zhang, Z., Stuedlein, A.W., Evans, T.M. (2021) Liquefaction Modeling for Biocemented Calcareous Sand. 147(12):04021149. https://doi.org/10.1061/(ASCE)GT.1943-5606.0002666.

[37] Xiao, Y., Wu, B.Y., Shi, J.Q., Wang, L., Liu, H.L. (2023b) Acoustic Emission of Biocemented Calcareous Sand Base. 23(9):04023153. https://doi.org/10.1061/IJGNAI.GMENG-8817.

[38] Xu, D. S., Zhao, H. X., Fan, X. C., & Qin, Y. (2023). Influence of spatial distribution of fine sand layers on the mechanical behavior of coral reef sand. Soil Dynamics and Earthquake Engineering, 169, Article 107897. https://doi.org/10.1016/j.soildyn.2023.107897

[39] Zhu, C. Q., Zhou, B., & Liu, H. F. (2014). Investigation on strength and microstracture of naturally cemented calcareous soil(in Chinese). Rock and Soil Mechanics, 35(06), 1655-1663. https://doi.org/10.16285/j.rsm.2014.06.011.