Structural Engineering and Mechanics

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Spalling resistance and mechanical performance of UHPC under high temperature using hybrid natural and artificial fibers

  • Arash K. Pour (Innovative Structural Engineering and Mechanics Group) ;
  • Amir Shirkhani (Department of Structural Engineering, Faculty of Civil Engineering, University of Tabriz) ;
  • Ehsan Noroozinejad Farsangi (Urban Transformations Research Centre (UTRC), Western Sydney University)
  • Received : 2022.06.30
  • Accepted : 2024.05.27
  • Published : 2024.07.25
⟨ Previous Next ⟩

Abstract

This research plans to investigate the simultaneous impact of bamboo fibers (BF) and steel fibers (SF) on the mechanical and spalling characteristics of ultra-high-performance concrete (UHPC) exposed to high temperatures (HT). To this aim, 25 mixtures were made and assessed. BF was added at five contents of 0, 2.5, 5, 7.5 and 10 kg/m3. Additionally, SF was used at five weight contents: 0%, 1%, 2%, 3% and 4%. Specimens were exposed to temperatures ranging between 25℃ and 800℃. Thus, com-pressive, tensile, and flexural strengths, elastic moduli, mass loss, and permeability were measured. Experiments revealed that the simultaneous use of low BF and SF contents could totally prevent spalling of UHPC, but the use of either SF or BF alone could not prevent spalling at high levels of fibers. Besides, the synergetic positive impact of BF and SF on the spalling resistance of UHPC was by reason of the rise of BF' permeability and the bridging role of SF at HT. Moreover, it was concluded that the use of SF could moderate the adverse influence of BF on the compressive resistance of UHPC.

Keywords

References

  1. Abid, M., Hou, X., Zheng, W. and Hussain, R.R. (2019), "Effect of fibers on high-temperature mechanical behavior and microstructure of reactive powder concrete", Mater., 12, 329. https://doi.org/0.3390/ma12020329.
  2. Abubakar, A.U. and Akcaoglu, T. (2021), "Influence of precompression on crack propagation in steel fiber reinforced concrete", Adv. Concrete Constr., 11, 261-270. https://doi.org/10.12989/acc.2021.11.3.261.
  3. ACI 363R-10 (2010), Report on High-Strength Concrete, ACI Committee 363, Farmington Hills, MI.
  4. ACI Committee 318, (2014), Building Code Requirements for Structural Concrete and Commentary, American Concrete Institute, Farmington Hills, MI.
  5. Aitcin, P. (2000), "Cements of yesterday and today-Concrete of tomorrow", Cement Concrete Res., 30, 1349-1359. https://doi.org/10.1016/S0008-8846(00)00365-3.
  6. Alsalman, A., Dang, C.N., Prinz, G.S. and Hale, W.M. (2017), "Evaluation of modulus of elasticity of ultra-high-performance concrete", Constr. Build. Mater., 153, 918-928. https://doi.org/10.1016/j.conbuildmat.2017.07.158.
  7. Amin, M., Zeyad, A.M., Agwa, I.S. and Rizk, M.S. (2024), "Effect of industrial wastes on the properties of sustainable ultra-high-performance concrete: Granite, ceramic, and glass", Constr. Build. Mater., 428, 136292. https://doi.org/10.1016/j.cscm.2022.e01149.
  8. Arioglu, N., Girgin, Z.C. and Arioglu, E. (2006), "Evaluation of ratio between splitting tensile strength and compressive strength for concrete up to 120 MPa and its application in strength criterion", ACI Mater. J., 103(1), 18-24. https://doi.org/10.14359/15123
  9. ASTM C29 (2020), Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens 1, ASTM International, ASTM Int.
  10. ASTM C293-07 (2007), Standard Test Method for Flexural Strength of Concrete using a Simple Beam with Center-Point Loading, ASTM International, ASTM Int.
  11. ASTM C33 (2018), Standard Specification for Concrete Aggregates, Annual Book of ASTM Standards, West Conshohocken, American Society for Testing and Materials, PA.
  12. ASTMC496/C496M-17 (2017), Standard Test Method for Splitting Tensile Strength of Cylindrical Concrete Specimens, ASTM International, ASTM Int.
  13. Atoyebi, O.D., Odeyemi, S.O. and Oram, J.A. (2018), "Experimental data on the splitting tensile strength of bamboo reinforced lateritic concrete using different culm sizes", Data Brief, 20, 1960-1964. https://doi.org/10.1016/j.dib.2018.09.064.
  14. Bae Martinez-Lopez, R. and Escalante-Garcia, J.I. (2016), "Alkali activated composite binders of waste silica soda-lime glass and blast furnace slag: Strength as a function of the composition", Constr. Build. Mater., 119, 119-129. https://doi.org/10.1016/j.conbuildmat.2016.05.064.
  15. Chen, Z., Wang, X., Ding, L., Jiang, K., Su, C., Liu, J. and Wu, Z. (2023), "Mechanical properties of a novel UHPC reinforced with macro basalt fibres", Constr. Build. Mater., 377, 131107. https://doi.org/10.1016/j.conbuildmat.2023.131107.
  16. Chen, Z., Wang, X., Ding, L., Jiang, K., Su, C., Liu. S. and Wu, Z. (2023), "Mechanical properties of a novel UHPC reinforced with macro basalt fibers", Constr. Build. Mater., 377, 131107. https://doi.org/10.1016/j.conbuildmat.2023.131107.
  17. Cheng, D., Jiang, S. and Zhang, Q. (2013), "Effect of hydrothermal treatment with different aqueous solutions on the mould resistance of bamboo with chemical and FTIR analysis", BioResour., 8, 371-382.
  18. CSA (2004), Design of Concrete Structures, Canadian Standard Association.
  19. Dehghani Ashkezari, G. and Razmara, M. (2020), "Thermal and mechanical evaluation of ultra-high-performance fibre-reinforced concrete and conventional concrete subjected to high temperatures", J. Build. Eng., 32, 101621. https://doi.org/10.1016/j.jobe.2020.101621.
  20. Dong, X., Ding, Y. and Wang, T.J. (2008), "Spalling and mechanical properties of fiber rein-forced high-performance concrete subjected to fire", Wuhan Univ. Technol.-Mater. Sci. Ed., 23, 743. https://doi.org/10.1007/s11595-007-5743-5.
  21. Du, R.Y., Huang, Q.W. and Chen, B.C. (2013), "Application and study of reactive powder concrete to bridge engineering", World Bridges, 41, 69-74.
  22. EN 1992-1-1 (1992), Eurocode 2: Design of Concrete Structures: Part 1-1: General Rules and Rules for Buildings, CEB, Brussels.
  23. Erdogdu, S. Kandil, U. and Nayir, S. (2019), "Effects of cement dosage and steel fibre ratio on the mechanical properties of reactive powder concrete", Adv. Concrete Constr., 8, 139-144. https://doi.org/10.12989/acc.2019.8.2.139.
  24. Farokhpour, M., Ghalehnovi, M., Karimi Pour, A. and Amanian, M. (2019), "Effect of polypropylene fibers on the behavior of recycled aggregate concrete", 5th National Conference on Recent Achievements in Civil Engineering, Architecture and Urbanism, Mashhad,
  25. Ganesan, N., Indira, P.V. and Irshad, P. (2017), "RCC frames with ferrocement and fiber rein-forced concrete infill panels under reverse cyclic loading", Adv. Concrete Constr., 5, 257-270. https://doi.org/10.12989/acc.2017.5.3.257.
  26. Gencel, O., Kazmi, S.M.S., Munir, M.J., Kaplan, G., Bayraktar, O.Y., Yarar, D.O., Karimi Pour, A. and Ahmad, M.R. (2021), "Influence of bottom ash and polypropylene fibers on the physico-mechanical, durability and thermal performance of foam concrete: An experimental investigation", Constr. Build. Mater., 306. 124887. https://doi.org/10.1016/j.conbuildmat.2021.124887.
  27. Ghalehnovi, M., Karimi Pour, A. and Chaboki, H.R. (2020), "Crack width and propagation in recycled coarse aggregate concrete beams reinforced with steel fibres", Appl. Sci., 10, 124-132.
  28. Graybeal, B.A. and Stone, B. (2012), "Compression response of a rapid-strengthening ultra-high performance concrete formulation", US Department of Transportation, Federal Highway Administration.
  29. Gulsan, M.E. Al Jawahery, M.S. Alshawaf, A.H. Hussein, T.A. and Abdulhaleem, K.N. (2018), "Rehabilitation of normal and self-compacted steel fibre reinforced concrete corbels via basalt fibre", Adv. Concrete Constr., 6, 423-463. https://doi.org/10.12989/acc.2018.6.5.423.
  30. Hager, I., Mroz, K. and Tracz, T. (2019), "Contribution of polypropylene fibres melting to permeability change in heated concrete-The fibre amount and length effect", IOP Conf. Ser. Mater. Sci. Eng., 706, 012009. https://doi.org/10.1088/1757-899X/706/1/012009
  31. Hajek, P. and Fiala, C. (2008), "Environmentally optimized floor slabs using UHPC-contribution to sustainable building", Proceedings of the 2nd International Symposium on Ultra-High-Performance Concrete, Kassel, Germany.
  32. Heinz, D. and Ludwig, H. (2004), "Heat treatment and the risk of DEF delayed ettringite formation in UHPC", Proceedings of the International Symposium on UHPC, Kassel, Germany.
  33. Jiang, K., Wang, X., Chen, Z., Ding, L., Peng, Z. and Wu, Z. (2022), "Effect of constituent content on mechanical behaviors of ultra-high performance seawater sea-sand concrete", Constr. Build. Mater., 351, 128952. https://doi.org/10.1016/j.conbuildmat.2022.128952.
  34. Jiang, K., Wang, X., Ding, L., Chen, Z., Liu, J. and Wu, Z. (2023), "Experimental study on pullout behaviour of basalt fiber-reinforced polymers minibar embedded in ultra-high-performance sea-water sea-sand concrete", J. Build. Eng., 68, 106160. https://doi.org/10.1016/j.jobe.2023.106160.
  35. Karimi Pour, A. (2020), "Effect of untreated coal waste as fine and coarse aggregates replacement on the properties of steel and polypropylene fibres reinforced concrete", Mech. Mater., 150, 103592. https://doi.org/10.1016/j.mechmat.2020.103592.
  36. Karimi Pour, A. (2023), "Thermal behavior of plain and fiber-reinforced rigid concrete airfield run-ways", Ph.D. Thesis, The University of Texas at El Paso, TX. USA.
  37. Karimi Pour, A., Ghalehnovi, M. and Gencel, O. (2022), "Torsional behaviour of rectangular high-performance fibre-reinforced concrete beams", Struct., 35, 511-519. https://doi.org/10.1016/j.istruc.2021.11.037.
  38. Karimi Pour, A., Ghalehnovi, M. and Golmohammadi, M. (2021), "Experimental investigation on the shear behavior of stud-bolt connectors of steel-concrete-steel fiber-reinforced recycled aggregates sandwich panels", Mater., 14, 5185. https://doi.org/10.3390/ma14185185.
  39. Karimi Pour, A., Shirkhani, A., Zeng, J.J., Zhuge, Y. and Noroozinejad Farsangi, E. (2023), "Experimental investigation of GFRP-RC beams with Polypropylene fibers and waste granite recycled aggregate", Struct., 50, 1021-1034. https://doi.org/10.1016/j.istruc.2023.02.068.
  40. Kim, J.J., Yoo, D.Y. and Banthia, N. (2021), "Benefits of curvilinear straight steel fibers on the rate-dependent pullout resistance of ultra-high-performance concrete", Cement Concrete Compos., 118, 103965. https://doi.org/10.1016/j.cemconcomp.2021.103965.
  41. Kim, R., Jo, J., Yoon, H. and Park, J.W. (2024), "Ultra-high-performance concrete alleviates eco-toxicological effects in aquatic organisms", Sci. Total Environ., 928, 172538. https://doi.org/10.1016/j.scitotenv.2024.172538.
  42. Kim, Y.H. (2008), "Characterization of self-consolidating concrete for the design of precast pre-tension bridge superstructure elements", PhD Thesis, Texas A&M University, USA.
  43. Le, H.V., Kim, M.K., Kim, D.J. and Park, J. (2021), "Electrical properties of smart ultra-high-performance concrete under various temperatures, humidities, and age of concrete", Cement Concrete Compos., 118, 103979. https://doi.org/10.1016/j.cemconcomp.2021.103979.
  44. Li, H. and Liu, G. (2016), "Tensile properties of hybrid fiber reinforced reactive powder concrete after expose to elevated temperature", Int. J. Concrete Struct. Mater., 10, 29-37. https://doi.org/10.1007/s40069-016-0125-z.
  45. Li, Y., Tan, K.H. and Yang, E.H. (2019), "Synergistic effects of hybrid polypropylene and steel fibers on explosive spalling prevention of ultra-high-performance concrete at elevated temperature", Cement Concrete Compos., 96, 174-181. https://doi.org/10.1016/j.cemconcomp.2018.11.009.
  46. Li, Y., Zhang, Y., Yang, E.H. and Tan, K.H. (2019), "Effects of geometry and fraction of poly-propylene fibers on the permeability of ultra-high-performance concrete after heat", Cement Concrete Res., 116, 168-178. https://doi.org/10.1016/j.cemconres.2018.11.009.
  47. Liang, X., Wu, C., Yang, Y. and Li, Z. (2019), "Experimental study on ultra-high-performance concrete with high fire resistance under the simultaneous effect of elevated temperature and im-pact loading", Cement Concrete Compos., 98, 29-38. https://doi.org/10.1016/j.cemconcomp.2019.01.017.
  48. Liu, J.C., Tan, K.H. and Zhang, D. (2017), "multi-response optimization of the post-fire performance of strain-hardening cementitious composite", Cement Concrete Compos., 80, 80-90. https://doi.org/10.1016/j.cemconcomp.2017.03.001.
  49. Magureanu, C., Sosa, I., Negrutiu, C. and Heghes, B. (2012), "Mechanical properties and durability of ultra-high-performance concrete", ACI Mater. J., 109, 177-183. https://doi.org/10.14359/51683704
  50. Mansouri, I., Shahheidari, F.S., Hashemi, S.M.A. and Farzampour, A. (2020), "Investigation of steel fiber effects on concrete abrasion resistance", Adv. Concrete Constr., 9, 367-374810. https://doi.org/10.12989/acc.2020.9.4.367.
  51. Marrero, R.E., Soto, H.L. Benitez, F.R., Medina, C. and Suarez, O.M. (2017), "Study of high-strength concrete reinforced with bamboo fibers", Mater. Energy Efficiency Sustain., 59, 125-138.
  52. Mathews, M.E., Anand, N., Kodur, V.K. and Arulraj, P. (2021), "The bond strength of self-compacting concrete exposed to elevated temperature", Proc. Inst. Civil Eng. Struct. Build., 174, 804-821. https://doi.org/10.1680/jstbu.20.00105.
  53. Metha, P.K. and Monteiro, P.J.M. (2006), Concrete, Microstructure, Properties and Materials, 3rd Edition, McGraw-Hill, New York, NY, USA.
  54. Mindess, S., Young, J.F. and Darwin, D. (2003), Concrete, 2nd Edition, Prentice-Hall, Upper Saddle River, NJ, USA.
  55. Noori, A., Lu, Y., Saffari, P., Liu, J. and Ke, J. (2021), "The effect of mercerization on thermal and mechanical properties of bamboo fibers as a bio-composite material: A review", Constr. Build. Mater., 279, 122519. https://doi.org/10.1016/j.conbuildmat.2021.122519.
  56. NS 3473 (1992), Concrete Structures Design Rules, Norway's National Standard.
  57. NZS 3101.1&2 (2006), Concrete Structures Standard: The Design of Concrete Structures, New Zealand Standard, Wellington, 6140.
  58. Onuaguluchi, O. and Banthia, N. (2016), "Plant-based natural fiber reinforced cement composites: A review", Cement Concrete Compos., 68, 96-108. https://doi.org/10.1016/j.cemconcomp.2016.02.014.
  59. Ozawa, M. and Morimoto, H. (2014), "Effects of various fibers on high-temperature spalling in high-performance concrete", Constr. Build. Mater., 71, 83-92. https://doi.org/10.1016/j.conbuildmat.2014.07.068.
  60. Racky, P. (2004), "Cost-effectiveness and sustainability of UHPC", Proceedings of the International Symposium on Ultra High-Performance Concrete, Kassel, Germany, September.
  61. Ramadoss, P. and Nagamani, K. (2008), "Tensile strength and durability characteristics of high strength-performance fibres reinforced concrete", Arab. J. Sci. Eng., 33, 215-224.
  62. Rashid, R.S.M., Salem, M.S., Azreen, N.M., Voo, Y.L., Haniza, M., Shukri, A.A. and Yahya, M.S. (2020), "Effect of elevated temperature to radiation shielding of ultra-high-performance concrete with silica sand or magnetite", Constr. Build. Mater., 262, 120567. https://doi.org/10.1016/j.conbuildmat.2020.120567.
  63. Ray, D., Sarkar, B., Basak, R. and Rana, A. (2020), "Study of the thermal behavior of alkali-treated jute fibers", J. Appl. Polym. Sci., 85, 2594-2599. https://doi.org/10.1002/app.10934.
  64. Ren, G., Gao, X. and Zhang, H. (2022), "Utilization of hybrid sisal and steel fibres to improve elevated temperature resistance of ultra-high-performance concrete", Cement Concrete Compos., 130, 104555. https://doi.org/10.1016/j.cemconcomp.2022.104555.
  65. Rezaiee-Pajand, M., Karimi Pour, A. and Mohebbi Najm Abad, J. (2020), "Crack spacing prediction of fibre-reinforced concrete beams with lap-spliced bars by machine learning models", Iran. J. Sci. Technol. Trans. Civil Eng., 45, 833-850. https://doi.org/10.1007/s40996-020-00441-6.
  66. Rustamov, S. and Kwon, M. (2021), "Effects of fiber types and volume fraction on strength of lightweight concrete containing expanded clay", Adv. Concrete Constr., 12, 47-55. https://doi.org/10.12989/acc.2021.12.1.047.
  67. Salih, A.A., Zulkifli, R. and Azhari, C.H. (2020), "Tensile properties and microstructure of alkali treatment", Fiber., 8, 1-10. https://doi.org/10.3390/fib8050026.
  68. Schmidt, D., Dehn, F. and Urbonas, L. (2004), "Fire resistance of ultra-high-performance concrete (UHPC)-Testing of laboratory samples and columns under load", Proceedings of the International Symposium on UHPC, Kassel, Germany.
  69. Sharma, R. and Bansal, P.P. (2019), "Efficacy of supplementary cementitious material and hybrid fiber to develop the ultra-high performance hybrid fiber reinforced concrete", Adv. Concrete Constr., 8, 21-31. https://doi.org/10.12989/acc.2019.8.1.021.
  70. Silva, F.D.A., Mobasher, B., Soranakom, C. and Filho, R.D.T. (2011), "Effect of fiber shape and morphology on interfacial bond and cracking behaviors of sisal fiber cement-based composites", Cement Concrete Compos., 33, 814-823. https://doi.org/10.1016/j.cemconcomp.2011.05.003.
  71. Su, X., Ren, Z. and Li, P. (2024), "Review on physical and chemical activation strategies for ultra-high-performance concrete (UHPC)", Cement Concrete Compos., 149, 105519. https://doi.org/10.1016/j.cemconcomp.2024.105519.
  72. Suescum-Morales, D., Rios, J.D., Concha, A.M.D.L., Cifuentes, H., Jimenez, J.R. and Fernandez, J.M. (2021), "Effect of moderate temperatures on compressive strength of ultra-high-performance concrete: A microstructural analysis", Cement Concrete Res., 140, 106303. https://doi.org/10.1016/j.cemconres.2020.106303.
  73. Sutcu, M., Gencel, O., Erdogmus, E., Kizinievic, O., Kizinievic, V., Karimi Pour, A. and Munoz Velasco, P. (2022), "Low cost and eco-friendly building materials derived from wastes: Combined effects of bottom ash and water treatment sludge", Constr. Build. Mater., 324, 126669. https://doi.org/10.1016/j.conbuildmat.2022.126669.
  74. Tai, S., Pan, H. and Kung, N. (2011), "Mechanical properties of steel fiber reinforced reactive powder concrete following exposure to high temperature reaching 800℃", Nucl. Eng. Des., 241, 2416-2424. https://doi.org/10.1016/j.nucengdes.2011.04.008.
  75. Turk, K., Kina, C. and Oztekin, E. (2020), "Effect of macro and microfiber volume on the flexural performance of hybrid fiber reinforced SCC", Adv. Concrete Constr., 10, 257-269. https://doi.org/10.12989/acc.2020.10.3.257.
  76. Wahyuni, A.S., Supriani, F. and Gunawan, A. (2014), "The performance of concrete with rice husk ash, seashell ash and bamboo fiber addition", Procedia Eng., 95, 473-478. https://doi.org/10.1016/j.proeng.2014.12.207.
  77. Walraven, J. (2008), "On the way to design recommendations for UHPFRC", Proceedings of the 2nd International Symposium on Ultra-High-Performance Concrete, Kassel, Germany, March.
  78. Way, R. and Wille, K. (2012), "Material characterization of an ultra-high-performance fibre-reinforced concrete under elevated temperature", Proceedings of the 3rd International Symposium on UHPC and Nanotechnology for High Performance Construction Materials, Kassel, Germany.
  79. Wei, J. (2018), "Degradation behavior and kinetics of sisal fiber in pore solutions of the sustainable cementitious composite containing metakaolin", Polym. Degrad. Stab., 150, 1-12. https://doi.org/10.1016/j.polymdegradstab.2018.01.027.
  80. Wei, J. and Meyer, C. (2014), "Degradation rate of natural fiber in cement composites exposed to various accelerated ageing environment conditions", Corros. Sci., 88, 118-132. https://doi.org/10.1016/j.corsci.2014.07.029.
  81. Wu, H., Lin, X. and Zhou, A. (2020), "A review of mechanical properties of fibre-reinforced concrete at elevated temperatures", Cement Concrete Res., 135, 106117. https://doi.org/10.1016/j.cemconres.2020.106117.
  82. Wu, L., Lu, Z., Zhuang, C., Chen, Y. and Hu, R. (2019), "Mechanical properties of nano SiO2 and carbon fiber reinforced concrete after exposure to high temperatures", Mater., 12, 3773. https://doi.org/10.3390/ma12223773.
  83. Wu, Z., Khayat, K.H. and Shi, C. (2018), "How do fibre shape and matrix composition affect fibre pullout behaviour and flexural properties of UHPC", Cement Concrete Compos., 90, 193-201. https://doi.org/10.1016/j.cemconcomp.2018.03.021.
  84. Wu, Z., Shi, C., He, W. and Wu, L. (2016), "Effects of steel fiber content and shape on mechanical properties of ultra-high-performance concrete", Constr. Build. Mater., 103, 8-14. https://doi.org/10.1016/j.conbuildmat.2015.11.028.
  85. Xu, B.W. and Shi, H.S. (2009), "Correlations among mechanical properties of steel fibre rein-forced concrete", Constr. Build. Mater., 23, 3468-3474. https://doi.org/10.1016/j.conbuildmat.2009.08.017.
  86. Xu, Z., Li, J., Wu, P. and Wu, C. (2021), "Experimental investigation of triaxial strength of ultra-high-performance concrete after exposure to elevated temperature", Constr. Build. Mater., 295, 123689. https://doi.org/10.1016/j.conbuildmat.2021.123689.
  87. Yoo, D.Y., Kim, S., Park, G.J. and Park, J.J. (2020), "Residual performance of HPFRCC ex-posed to fire-effects of matrix strength, synthetic fiber, and fire duration", Constr. Build. Mater., 241, 118038. https://doi.org/10.1016/j.conbuildmat.2020.118038.
  88. Zhang, D. and Tan, K.H. (2020), "Effect of various polymer fibers on spalling mitigation of ultra-high-performance concrete at high temperature", Cement Concrete Compos., 114, 103815. https://doi.org/10.1016/j.cemconcomp.2020.103815.
  89. Zhang, D., Liu, Y. and Tan, K.H. (2021), "Spalling resistance and mechanical properties of strain-hardening ultra-high-performance concrete at elevated temperature", Constr. Build. Mater., 266, 120961. https://doi.org/10.1016/j.conbuildmat.2020.120961.
  90. Zhang, D., Tan, G.Y. and Tan, K.H. (2021), "Combined effect of flax fibers and steel fibers on spalling resistance of ultra-high-performance concrete at high temperature", Cement Concrete Compos., 121, . https://doi.org/10.1016/j.cemconcomp.2021.104067.
  91. Zhang, D., Tan, K.H., Dasari, A. and Weng, Y. (2020), "Effect of natural fibers on thermal spalling resistance of ultra-high-performance concrete", Cement Concrete Compos., 109, 103512. https://doi.org/10.1016/j.cemconcomp.2020.103512.
  92. Zhang, T., Zhu, H., Zhou, L. and Yan, Z. (2021), "multi-level micromechanical analysis of elastic properties of ultra-high-performance concrete at high temperatures: Effects of imperfect interface and inclusion size", Compos. Struct., 262, 113548. https://doi.org/10.1016/j.compstruct.2021.113548.
  93. Zhang, X., Pan, J. and Yang, B. (2017), "Experimental study on the mechanical performance of bamboo fiber reinforced concrete", Appl. Mech. Mater., 15, 174-177. https://doi.org/10.4028/www.scientific.net/AMM.174-177.1219
  94. Zheng, W., Li, H. and Wang, Y. (2012), "Compressive stress-strain relationship of steel fiber rein-forced reactive powder concrete after exposure to elevated temperatures", Constr. Build. Mater., 35, 931-940. https://doi.org/10.1016/j.conbuildmat.2012.05.031.
  95. Zheng, W., Luo, B. and Wang, Y. (2014), "Microstructure and mechanical properties of RPC containing PP fibers at elevated temperatures", Mag. Concrete Res., 66, 397-408. https://doi.org/10.1680/macr.13.00232.
  96. Zhu, Y., Hussein, H., Kumar, A. and Chen, G. (2021), "A review: Material and structural properties of UHPC at elevated temperatures or fire conditions", Cement Concrete Compos., 123, 104212. https://doi.org/10.1016/j.cemconcomp.2021.104212.
  97. Zollo, R.F. (1997), "Fiber-reinforced concrete: An overview after 30 years of development", Cement Concrete Compos., 19, 107-122. https://doi.org/10.1016/S0958-9465(96)00046-7.