Microencapsulated Phase Change Material in Asphalt for Urban Heat Island Mitigation: A Critical Review of Laboratory-Based Experimental Evidence.

Urban heat island (UHI) intensification is strongly associated with dark, impervious pavements that absorb, store, and re-radiate solar energy. Among emerging pavement-cooling strategies, phase change materials (PCMs) offer a latent-heat-based mechanism for moderating thermal peaks without relying solely on reflectivity or permeability. In asphalt systems, however, direct PCM incorporation is constrained by leakage, incompatibility with bitumen, and thermo-mechanical instability during mixing and service. Microencapsulation has therefore emerged as a leading strategy because it protects the PCM core, improves dispersion, and enhances thermal durability. By analyzing laboratory-based literature on microencapsulated PCM (MPCM) integrated into asphalt binders and asphalt mixtures, this study evaluates the effectiveness of MPCM in asphalt, its performance in the management of pavement heat, thermal regulation performance, mechanical implications, and research gaps.

Urban Heat Island (UHI), asphalt pavement, phase change material (PCM), microencapsulation

1. Al-Khateeb, G. G., Sukkari, A., Ezzat, H., Nasr, E., & Zeiada, W. (2024). Rheology of Crumb Rubber-Modified Warm Mix Asphalt (WMA). Polymers, 16(7), 906. https://doi.org/10.3390/polym16070906 [Google Scholar] [Crossref]

2. Almutairi, H., & Baaj, H. (2023). Rheological, Spectroscopic, and Chemical Characterization of Asphalt Binders Modified with Phase Change Materials, Polymers, and Glass Powder. Applied Sciences, 13(8), 4875. https://doi.org/10.3390/app13084875 [Google Scholar] [Crossref]

3. Alva, G., Liu, L., Huang, X., & Fang, G. (2017). Thermal energy storage materials and systems for solar energy applications. Renewable and Sustainable Energy Reviews, 68, 693–706. https://doi.org/10.1016/j.rser.2016.10.021 [Google Scholar] [Crossref]

4. Anupam, B. R., Sahoo, U. C., & Rath, P. (2020). Phase change materials for pavement applications: A review. Construction and Building Materials, 247, 118553. https://doi.org/10.1016/j.conbuildmat.2020.118553 [Google Scholar] [Crossref]

5. Athukorallage, B., Dissanayaka, T., Senadheera, S., & James, D. (2018). Performance analysis of incorporating phase change materials in asphalt concrete pavements. Construction and Building Materials, 164, 419–432. https://doi.org/10.1016/j.conbuildmat.2017.12.226 [Google Scholar] [Crossref]

6. Bueno, M., Kakar, M. R., Refaa, Z., Worlitschek, J., Stamatiou, A., & Partl, M. N. (2019). Modification of asphalt mixtures for cold regions using microencapsulated phase change materials. Scientific Reports, 9(1), 20342. https://doi.org/10.1038/s41598-019-56808-x [Google Scholar] [Crossref]

7. Cárdenas-Ramírez, C., Jaramillo, F., & Gómez, M. (2020). Systematic review of encapsulation and shape-stabilization of phase change materials. Journal of Energy Storage, 30, 101495. https://doi.org/10.1016/j.est.2020.101495 [Google Scholar] [Crossref]

8. Chen, Y., Wang, H., You, Z., & Hossiney, N. (2020). Application of phase change material in asphalt mixture – A review. Construction and Building Materials, 263, 120219. https://doi.org/10.1016/j.conbuildmat.2020.120219 [Google Scholar] [Crossref]

9. Cheng, C., Cheng, G., Gong, F., Fu, Y., & Qiao, J. (2021). Performance evaluation of asphalt mixture using polyethylene glycol polyacrylamide graft copolymer as solid–solid phase change materials. Construction and Building Materials, 300, 124221. https://doi.org/10.1016/j.conbuildmat.2021.124221 [Google Scholar] [Crossref]

10. Da Rocha Segundo, I. G., Margalho, É. M., Lima, O. D. S., Pinheiro, C. G. D. S., De Freitas, E. F., & Carneiro, J. A. S. A. O. (2023). Smart Asphalt Mixtures: A Bibliometric Analysis of the Research Trends. Coatings, 13(8), 1396. https://doi.org/10.3390/coatings13081396 [Google Scholar] [Crossref]

11. Dai, J., Ma, F., Fu, Z., Li, C., Jia, M., Shi, K., Wen, Y., & Wang, W. (2021). Applicability assessment of stearic acid/palmitic acid binary eutectic phase change material in cooling pavement. Renewable Energy, 175, 748–759. https://doi.org/10.1016/j.renene.2021.05.063 [Google Scholar] [Crossref]

12. Dai, J., Ma, F., Sangiorgi, C., Tarsi, G., Fu, Z., Tataranni, P., Li, C., & Hou, Y. (2024). Assessment of high-enthalpy composite eutectic phase change materials efficiency in asphalt binders for cooling pavements. Journal of Cleaner Production, 442, 140999. https://doi.org/10.1016/j.jclepro.2024.140999 [Google Scholar] [Crossref]

13. Deng, Y., Shi, X., Kou, Y., Chen, J., & Shi, Q. (2022). Optimized design of asphalt concrete pavement containing phase change materials based on rutting performance. Journal of Cleaner Production, 380, 134787. https://doi.org/10.1016/j.jclepro.2022.134787 [Google Scholar] [Crossref]

14. Du, X., Xin, C., Zhao, Y., Qiao, H., Chen, J., & Xu, R. (2025). Improvement of phase change modified asphalt thermal conductivity by phase change micro-capsule wall material. Construction and Building Materials, 487, 142121. https://doi.org/10.1016/j.conbuildmat.2025.142121 [Google Scholar] [Crossref]

15. Du, Y., Liu, P., Wang, J., Wang, H., Hu, S., Tian, J., & Li, Y. (2019). Laboratory investigation of phase change effect of polyethylene glycolon on asphalt binder and mixture performance. Construction and Building Materials, 212, 1–9. https://doi.org/10.1016/j.conbuildmat.2019.03.308 [Google Scholar] [Crossref]

16. Fareed, A., Baditha, A. K., Ali, A., Mehta, Y., Nallar, M., & Lu, P. (2025). Impact of Aging on the Performance of Microencapsulated Phase Change Materials in Asphalt Binder across Variable Temperature Range. Transportation Research Record: Journal of the Transportation Research Board, 2679(11), 274–291. https://doi.org/10.1177/03611981251347297 [Google Scholar] [Crossref]

17. Fu, Z., Hou, Y., Ma, F., Fu, Z., Cui, J., Liu, Z., & Liu, J. (2024). Investigation of rheological properties of asphalt modified with low-temperature microencapsulated eutectic phase change materials. Case Studies in Construction Materials, 20, e03201. https://doi.org/10.1016/j.cscm.2024.e03201 [Google Scholar] [Crossref]

18. Gao, N., Tang, T., Xiang, H., Zhang, W., Li, Y., Yang, C., Xia, T., & Liu, X. (2022). Preparation and structure-properties of crosslinking organic montmorillonite/polyurethane as solid-solid phase change materials for thermal energy storage. Solar Energy Materials and Solar Cells, 244, 111831. https://doi.org/10.1016/j.solmat.2022.111831 [Google Scholar] [Crossref]

19. Gong, X., Liu, W., & Ying, H. (2022). Phase Change Heat-induced Structure of Asphalt Pavement for Reducing the Pavement Temperature. Iranian Journal of Science and Technology, Transactions of Civil Engineering, 46(2), 1655–1668. https://doi.org/10.1007/s40996-021-00670-3 [Google Scholar] [Crossref]

20. Guo, M., Cheng, X., Wei, S., Xiu, H., & Song, S. (2024). The State of the Art on Phase Change Material-Modified Asphalt Pavement. Sustainability, 16(20), 8796. https://doi.org/10.3390/su16208796 [Google Scholar] [Crossref]

21. Hu, H., Chen, W., Cai, X., Xu, T., Cui, H., Zhou, X., Chen, J., Huang, G., & Sun, Y. (2021). Study on preparation and thermal performance improvements of composite phase change material for asphalt steel bridge deck. Construction and Building Materials, 310, 125255. https://doi.org/10.1016/j.conbuildmat.2021.125255 [Google Scholar] [Crossref]

22. Ismael, S. F., Alias, A. H., Haron, N. A., Zaidan, B. B., & Abdulghani, A. M. (2024). Mitigating Urban Heat Island Effects: A Review of Innovative Pavement Technologies and Integrated Solutions. Structural Durability & Health Monitoring, 18(5), 525–551. https://doi.org/10.32604/sdhm.2024.050088 [Google Scholar] [Crossref]

23. Jin, J., Chen, H., Liu, S., Xiao, M., & Liu, L. (2024). Study on preparation and properties of phase change modified asphalt for the functional pavement. Construction and Building Materials, 439, 137248. https://doi.org/10.1016/j.conbuildmat.2024.137248 [Google Scholar] [Crossref]

24. Jin, J., Lin, F., Liu, R., Xiao, T., Zheng, J., Qian, G., Liu, H., & Wen, P. (2017). Preparation and thermal properties of mineral-supported polyethylene glycol as form-stable composite phase change materials (CPCMs) used in asphalt pavements. Scientific Reports, 7(1), 16998. https://doi.org/10.1038/s41598-017-17224-1 [Google Scholar] [Crossref]

25. Kheradmand, M., Castro-Gomes, J., Azenha, M., Silva, P. D., De Aguiar, J. L. B., & Zoorob, S. E. (2015). Assessing the feasibility of impregnating phase change materials in lightweight aggregate for development of thermal energy storage systems. Construction and Building Materials, 89, 48–59. https://doi.org/10.1016/j.conbuildmat.2015.04.031 [Google Scholar] [Crossref]

26. Korniejenko, K., Nykiel, M., Choinska, M., Jexembayeva, A., Konkanov, M., & Aruova, L. (2024). An Overview of Phase Change Materials and Their Applications in Pavement. Energies, 17(10), 2292. https://doi.org/10.3390/en17102292 [Google Scholar] [Crossref]

27. Li, J., Li, Q., Luo, B., Luo, Y., Ye, S., Du, P., & Zhang, H. (2025). Temperature-regulating asphalt mixture incorporating phase change and high-reflective materials: Thermal behavior and mechanical performance. Construction and Building Materials, 502, 144382. https://doi.org/10.1016/j.conbuildmat.2025.144382 [Google Scholar] [Crossref]

28. Liu, X., Cheng, X., Wang, S., Wei, S., Guo, M., Song, S., & Zhang, F. (2025). Study on the Thermal and Rheological Properties of Nano-TiO2-Modified Double Phase Change Asphalt. Materials, 18(20), 4799. https://doi.org/10.3390/ma18204799 [Google Scholar] [Crossref]

29. Liu, Z., Wei, K., Wang, S., Ma, B., Wang, X., Shi, W., & Xu, J. (2021). Effect of high-temperature-resistant epoxy resin/polyethylene glycol 2000 composite stereotyped phase change material particles on asphalt properties. Construction and Building Materials, 300, 124007. https://doi.org/10.1016/j.conbuildmat.2021.124007 [Google Scholar] [Crossref]

30. Ma, F., Hou, Y., Zhang, T., Fu, Z., Wen, Y., Dong, W., Shi, K., Dai, J., & Yuan, K. (2026). Design of melamine-urea-formaldehyde shell microencapsulated aliphatic-based phase change materials for asphalt modification: Preparation and performance evaluation. Thermal Science and Engineering Progress, 69, 104444. https://doi.org/10.1016/j.tsep.2025.104444 [Google Scholar] [Crossref]

31. Mohajerani, A., Bakaric, J., & Jeffrey-Bailey, T. (2017). The urban heat island effect, its causes, and mitigation, with reference to the thermal properties of asphalt concrete. Journal of Environmental Management, 197, 522–538. https://doi.org/10.1016/j.jenvman.2017.03.095 [Google Scholar] [Crossref]

32. Özdemir, A. M., Kök, B. V., Yıldırım, F., & Aydoğmuş, E. (2025). Effect of microencapsulated phase change material on the rheological and thermal properties of asphalt binder. Journal of Materials Research and Technology, 39, 2322–2339. https://doi.org/10.1016/j.jmrt.2025.09.246 [Google Scholar] [Crossref]

33. Pinheiro, C., Salmon LandiJr, LimaJr, O., Ribas, L., Hammes, N., Iran Rocha Segundo, Natália Cândido Homem, Verônica Castelo Branco, Freitas, E., Manuel Filipe Costa, & Carneiro, J. (2023). Advancements in Phase Change Materials in Asphalt Pavements for Mitigation of Urban Heat Island Effect: Bibliometric Analysis and Systematic Review. Sensors, 23(18), 7741. ProQuest Central; Publicly Available Content Database (2869630074). https://doi.org/10.3390/s23187741 [Google Scholar] [Crossref]

34. Qin, Y. (2015). A review on the development of cool pavements to mitigate urban heat island effect. Renewable and Sustainable Energy Reviews, 52, 445–459. https://doi.org/10.1016/j.rser.2015.07.177 [Google Scholar] [Crossref]

35. Rashid, F. L., Al-Obaidi, M. A., Hatem, W. A., Almuhanna, R. R. A., Abdul Redha, Z. A., Al Maimuri, N. M. L., & Dulaimi, A. (2025). Assessing the Effect of Organic, Inorganic, and Hybrid Phase Change Materials on Thermal Regulation and Energy Efficiency in Asphalt Pavements—A Review. Processes, 13(3), 597. https://doi.org/10.3390/pr13030597 [Google Scholar] [Crossref]

36. Refaa, Z., Kakar, M. R., Stamatiou, A., Worlitschek, J., Partl, M. N., & Bueno, M. (2018). Numerical study on the effect of phase change materials on heat transfer in asphalt concrete. International Journal of Thermal Sciences, 133, 140–150. https://doi.org/10.1016/j.ijthermalsci.2018.07.014 [Google Scholar] [Crossref]

37. Rouzmehr, F., & Jamshidi, S. (2025). Pavements and the Urban Heat Island Effect: A Network Analysis of Research Trends and Knowledge Structure. Infrastructures, 10(12), 344. https://doi.org/10.3390/infrastructures10120344 [Google Scholar] [Crossref]

38. Ryms, M., Lewandowski, W. M., Klugmann-Radziemska, E., Denda, H., & Wcisło, P. (2015). The use of lightweight aggregate saturated with PCM as a temperature stabilizing material for road surfaces. Applied Thermal Engineering, 81, 313–324. https://doi.org/10.1016/j.applthermaleng.2015.02.036 [Google Scholar] [Crossref]

39. Salvo-Ulloa, D., Indacoechea-Vega, I., Ossio, F., & Castro-Fresno, D. (2025). Critical factors for the selection of phase change materials for asphalt mixtures: A systematic review. Cleaner Engineering and Technology, 26, 100936. https://doi.org/10.1016/j.clet.2025.100936 [Google Scholar] [Crossref]

40. Sha, A., Zhang, J., Jia, M., Jiang, W., & Jiao, W. (2022). Development of polyurethane-based solid-solid phase change materials for cooling asphalt pavements. Energy and Buildings, 259, 111873. https://doi.org/10.1016/j.enbuild.2022.111873 [Google Scholar] [Crossref]

41. Tutu, K. A., & Tuffour, Y. A. (2016). Warm-Mix Asphalt and Pavement Sustainability: A Review. Open Journal of Civil Engineering, 06(02), 84–93. https://doi.org/10.4236/ojce.2016.62008 [Google Scholar] [Crossref]

42. Wang, C., Wang, Z.-H., Kaloush, K. E., & Shacat, J. (2021). Cool pavements for urban heat island mitigation: A synthetic review. Renewable and Sustainable Energy Reviews, 146, 111171. https://doi.org/10.1016/j.rser.2021.111171 [Google Scholar] [Crossref]

43. Wang, S., Wei, K., Shi, W., Cheng, P., Shi, J., & Ma, B. (2022). Study on the rheological properties and phase-change temperature regulation of asphalt modified by high/low-temperature phase change material particles. Journal of Energy Storage, 56, 105970. https://doi.org/10.1016/j.est.2022.105970 [Google Scholar] [Crossref]

44. Wang, Y., Xu, Y., Zhao, H., Cao, R., Huang, B., & Xu, L. (2025). Preparation and Characterization of Microencapsulated Phase Change Materials with Enhanced Thermal Performance for Cold Storage. Materials, 18(9), 2074. https://doi.org/10.3390/ma18092074 [Google Scholar] [Crossref]

45. Wei, K., Ma, B., Huang, X., Xiao, Y., & Liu, H. (2019). Influence of NiTi alloy phase change heat-storage particles on thermophysical parameters, phase change heat-storage thermoregulation effect, and pavement performance of asphalt mixture. Renewable Energy, 141, 431–443. https://doi.org/10.1016/j.renene.2019.04.026 [Google Scholar] [Crossref]

46. Wei, K., Wang, Y., & Ma, B. (2019). Effects of microencapsulated phase change materials on the performance of asphalt binders. Renewable Energy, 132, 931–940. https://doi.org/10.1016/j.renene.2018.08.062 [Google Scholar] [Crossref]

47. Wong, T. L. X., Lim, E. L., Mohd Hasan, M. R., Sougui, O. O., Milad, A., & Qu, X. (2024). Effectiveness of heat-reflective asphalt pavements in mitigating urban heat islands: A systematic literature review. Journal of Road Engineering, 4(4), 399–420. https://doi.org/10.1016/j.jreng.2024.04.008 [Google Scholar] [Crossref]

48. Wu, L., Liu, Q., Tang, N., Wang, X., Gao, L., Wang, Q., Lv, G., & Hu, L. (2022). Development of two-dimensional nano Mts/SA phase change materials for self-adjusting temperature of pavement. Construction and Building Materials, 349, 128753. https://doi.org/10.1016/j.conbuildmat.2022.128753 [Google Scholar] [Crossref]

49. Yang, J., Wang, Z.-H., Kaloush, K. E., & Dylla, H. (2016). Effect of pavement thermal properties on mitigating urban heat islands: A multi-scale modeling case study in Phoenix. Building and Environment, 108, 110–121. https://doi.org/10.1016/j.buildenv.2016.08.021 [Google Scholar] [Crossref]

50. Zhang, D., Bu, W., Wang, Q., Liu, P., Shao, Z., Liu, X., Li, G., & Zhou, Y. (2023). A review of recent developments and challenges of using phase change materials for thermoregulation in asphalt pavements. Construction and Building Materials, 400, 132669. https://doi.org/10.1016/j.conbuildmat.2023.132669 [Google Scholar] [Crossref]

51. Zhang, D., Chen, M., Wu, S., & Liu, P. (2021). Effect of expanded graphite/polyethylene glycol composite phase change material (EP-CPCM) on thermal and pavement performance of asphalt mixture. Construction and Building Materials, 277, 122270. https://doi.org/10.1016/j.conbuildmat.2021.122270 [Google Scholar] [Crossref]

52. Zhang, J., & Xu, T. (2024). Developments and thermal properties of thermochromic microcapsule and thermochromic asphalt-based composite coatings. Construction and Building Materials, 438, 137184. https://doi.org/10.1016/j.conbuildmat.2024.137184 [Google Scholar] [Crossref]

53. Zhang, L., Wang, J., Wu, J., Zhang, R., Guo, Y., Shen, H., Liu, X., & Li, K. (2025). Low-Temperature Performance and Thermal Control of Asphalt Modified with Microencapsulated Phase-Change Materials. Coatings, 15(8), 879. https://doi.org/10.3390/coatings15080879 [Google Scholar] [Crossref]

54. Zhu, S., Ji, T., Niu, D., & Yang, Z. (2020). Investigation of PEG/mixed metal oxides as a new form-stable phase change material for thermoregulation and improved UV ageing resistance of bitumen. RSC Advances, 10(73), 44903–44911. https://doi.org/10.1039/D0RA08398D [Google Scholar] [Crossref]

• Hysteresis Behaviour and Energy Dissipation of Niger Delta Soil under Cyclic Loading Conditions
• Exploring Bamboo Leaf Ash as Supplementary Cementitious Material for Enhanced Performance in Compressive and Tension in Mortar Strength as Construction Materials
• Effect of Using a Combination of 50% Coal Dust 50 % Course Sand as Filler in Bituminous Mix Design
• A Review of the Current State of Lean Construction in Nairobi City County
• Adaptation of Crumb Rubber Modified Asphalt Predictive Models for Nigerian Climatic Conditions: A Transfer Learning Approach