Multiple functional coating for preventive maintenance of civil and building infrastructures

Among the many solutions to improve the durability and energy efficiency of concrete buildings and infrastructures, surface coating is one of the most cost-effective and attractive preventive maintenance technologies. This technology can prevent the ingress of harmful substances (e.g., water, chloride ions, carbon dioxide, sulfate) from external environments that lead to the deterioration of concrete buildings and infrastructures. On the other hand, it can be combined with passive cooling technologies (such as heat insulation, reflection or heat radiation) to reduce the energy consumption of air conditioning required to maintain the indoor human comfort.


Our research on multi-functional coatings for concrete buildings and infrastructures mainly include the following two categories: surface treatment coating and surface film-forming coating. Regarding the former, the main functional parts of the coating are active treatment agent, which can penetrate into and react in-situ with the concrete substrate to enhance the compactness of the concrete (i.e., pore sealer) or change the chemical environment of the concrete pore structure (i.e., pore liner), thereby providing pore blocking or water-repellent effect. For the latter, the film-form coating has the maximum flexibility to be entitled with multiple functions through incorporating various functional components.


Our present research is focused on the development of eco-friendly (e.g., waterborne, fully using water as solvent or dispersant) multifunctional building coatings that are featured with the properties of self-cleaning (e.g., super-hydrophobic), anti-corrosion (e.g., labyrinth effect, improving the barrier effect to increase electrochemical resistance) and energy-saving (e.g. passive cooling), to provide innovative solutions for the green and sustainable development of concrete buildings.

Fig. 3.1 Development of surface treatment coatings
Fig. 3.2 Development of multiple-functional coating films

Selected Publications

  1. Wang, T., Zheng, J.J. and Dai, J.G.* (2021), Analysis of time-dependent chloride diffusion in surface-treated concrete based on a rapid numerical approach, Structures and Infrastructure Engineering. (DOI)

  2. Xue, X., Qiu, M., Li, Y., Zhang, Q.M., Li, S., Yang, Z., Feng, C., Zhang, W.D.*, Dai, J.G.*, Lei, D.Y.*, Jin, W., Xu, L., Zhang, T., Qin, J., Wang, H.Q. and Fan, S.H. (2020), Creating an Eco-Friendly Building Coating with Smart Sub-ambient Radiative Cooling, Advanced Materials. (DOI)

  3. Zeng, Y., Zhang, D.-W.*, Dai, J.-G., Fang, M.-S., Jin, W.-L. (2020). Determining the service life extension of silane treated concrete structures: A probabilistic approach.  Construction and Building Materials. 249, 118802. (DOI)

  4. Xue, X., Liu, Y.L., Dai, J.G.*, Poon, C.S., Zhang, W.D. and Zhang, P. (2018), Inhibiting Efflorescence Formation on Fly Ash-based Geopolymer via Silane Surface Modification, Cement and Concrete Composites, 94: 42-52. (DOI)

  5. Yang, Z., Xue, X., Dai, J.G. et al. (2018), Study of a super-non-wetting self-cleaning solar reflective blue-grey paint coating with luminescence, Solar Energy Materials and Solar Cells, 176:69-80. (DOI)

  6. Xue, X., Yang, Z., Li. Y.W., Sun, P.C., Feng, Y., Qu, T.J., Dai, J.G.*, Zhang, T., Qin, J., Xu, L.J. and Zhang, W.D.* (2018), Superhydrophobic self-cleaning solar reflective orange-gray paint coating, Solar Energy Materials and Solar Cells, 174, 2018, 292-299. (DOI)

  7. Xue, X., Li, Y., Yang, Z., He, Z., Dai, J.G.*, Xu, L., Zhang, W.* (2017), A systematic investigation of the water proofing performance and chloride resistance of a self-developed waterborne silane-based hydrophobic agent for mortar and concrete, Construction and Building Materials, 155:939-946. (DOI)

  8. Dai, J.G., Yokota, H., Zhao, T.J. and Zhang, P. (2017), Proceedings of the Eight International Conference on Water Repellent Treatment and Protective Surface Technology for Building Materials (HYDROPHOBE VIII), 7-9 December 2017, Hong Kong, China, ISBN 978-962-367-816-2.

  9.  Dai, J. G.*, Akira, Y., Wittmann, Folker H., Yokota, H. and Zhang, P. (2010), Water Repellent Surface Impregnation for Extending the Service Life of Reinforced Concrete Structures in Marine Environments: the Role of Cracks, Cement and Concrete Composites, 32(2), 101-109. (DOI)

  10.   Dai, J.G. Akira, Y., Kato, E. and Yokota, H. (2008), Effectiveness of Water Repellents for the Establishment of a Chloride Barrier in Reinforced Concrete with Cracks, Restoration of Buildings and Monuments - An International Journal, 14(6),426-435.

  11.   Dai, J.G., Akira, Y., Yokota, H. and Wittmann, Folker H. (2007), Various Surface Impregnation Treatments for Pre-conditioned Concrete Subjected to Seawater Immersion Tests, Restoration of Buildings and Monuments - An International Journal, 13(4), 229-240.

  12. Wang, T., Dai, J.G., Yang, L.H. and Wu. P. (2017), Theoretical Model for Electronic Migration of Chloride Ions in Water Repellent Concrete 【硅烷憎水处理混凝土的氯离子电场迁移模型研究】, China Civil Engineering Journal【土木工程学报】, 50(1): 20-27. 

  13. Zhang, P., Zhao T., Dai, J. G., Guo, P. and Wittmann, F. H. (2011), Experimental Study of the Water Repellency and Chloride Resistance of Modified Concrete with Silane 【硅烷改性混凝土防水和抗氯离子性能试验研究】, China Civil Engineering Journal 【土木工程学报】, 44(3), 71-78. 

  14. Zhang P., Dai, J.G., Zhao, T. J., Wittmann F. H and Jin, Z.Q. (2010), Water Absorption Property of Cracked Concrete and Effect of Water Repellent Treatment 【带裂缝混凝土的吸水性能及防水处理的影响】, Journal of Building Materials 【建筑材料学报】, 13(1), 70-74 . 

  15.  Zhang, P., Dai, J.G., Zhao, T.J., Wittmann, F. H. and Hartmann S. (2009), Water Repellent Treatment on Surface of Cracked Concrete under Seawater Exposure Environment 【海水暴露环境下带裂缝混凝土的表面防水处理】, Journal of Building Materials 【建筑材料学报】, 12(2), 214-218.

  16.  Akira, Y., Dai, J.G., Kato, E. and Yokota, H. (2008), Evaluation on Repair of Coastal Reinforced Concrete Structures using Surface Impregnation Method【港湾 RC 構造物に吸水防止材を適用した場合の補修効果について】, Proceeding of the Japan Concrete Institute【コンクリート工学年次論文集】, 30(2), 631-636. (in Japanese)

  17. Akira, Y., Dai, J.G., Kato, E. and Yokota, H. (2007), Effects of Moisture Conditions of Concrete on the Surface Impregnation Repair【コンクリートの含水状態が表面含浸材の補修性能に与える影響について】, Proceedings of the Japan Concrete Institute【コンクリート工学年次論文集】 29(3), 535-540. 


Selected Projects:

  • RGC GRF 2020/2021 Round, PI, Development of Multiple Functional Geopolymer Coating for Performance Upgrading of Concrete Building Structures, HK$873,995, Project Code: 15223120.

  • ECF 2017 Round, PI, Development of an Energy-Saving coating system for sustainable building envelope, HK$1,313,240, Project code: ECF/81/2017, Co-I: Prof C.S. Poon (PolyU).

  • CNERC project, Self-cleaning Eco-friendly Advanced Coating for Steel Corrosion Prevention in Marine Infrastructures, Project code: BBVA, HK$388,000, 03/2019-09/2020.

  • PolyU Post-doctoral Fellowship, Development of an Energy-Efficient Waterproof Coating System for Concrete Envelope, Project code: G-YW2F, 02/2017~04/2019, HK$645,000. Co-I: Prof CS Poon (PolyU).

Dai Group on Sustainable
           Concrete Infrastructure
                         -Emerging Materials and Structural Systems