Title:
Effects Of Post-Fire Curing on Self-Sensing Behavior of Smart Mortars
Author(s):
G. H. Nalon, J. C. L. Ribeiro, L. G. Pedroti, E. N. D. de Araujo, J. M. F. de Carvalho, G. E. S. de Lima, and S. O. Ferreira
Publication:
Materials Journal
Volume:
120
Issue:
1
Appears on pages(s):
181-192
Keywords:
carbon nanomaterials; high temperatures; post-fire curing; selfsensing concrete; smart cement-based composites; structural health monitoring (SHM)
DOI:
10.14359/51738459
Date:
1/1/2023
Abstract:
Post-fire rehydration is an interesting method to recover the structural performance of fire-damaged concrete. This paper evaluated the viability of using cementitious materials containing carbon nanotubes (CNTs) or carbon-black nanoparticles (CBNs) for damage recovery detection and self-monitoring of strain and stress of fire-damaged structures subjected to post-fire curing. Nanomodified mortars were subjected to high temperatures, rehydration, and measurements of capacitive behavior, electrical resistivity, and
self-sensing properties. After 600°C and rehydration, mortars with 9.00% of CBN presented the ability of self-detection of damage recovery, as also verified in mortars with 0.4 to 1.20% of CNT and 6.00% of CBN after 400°C and rehydration. The post-fire curing method filled the pores and microcracks of the cementitious matrix with nonconductive rehydration products, increasing their electrical resistivity. Mortars with 0.80 and 1.20% of CNT presented self-monitoring of strain and stress after 400°C and rehydration, as also observed in mortars with 9.00% of CBN after 600°C and rehydration. The post-fire curing process also increased the selfsensing properties because nonconductive rehydration products obstructed conductive stretches, improving tunneling conduction mechanisms rather than contacting conduction. These self-sensing materials are promising alternatives to evaluate post-fire curing processes and self-monitor the strain and stresses of next-generation
smart structures.
Related References:
1. Poon, C.-S.; Azhar, S.; Anson, M.; and Wong, Y.-L., “Strength and Durability Recovery of Fire-Damaged Concrete after Post-Fire-Curing,” Cement and Concrete Research, V. 31, No. 9, Sept. 2001, pp. 1307-1318. doi: 10.1016/S0008-8846(01)00582-8
2. Memon, S. A.; Shah, S. F. A.; Khushnood, R. A.; and Baloch, W. L., “Durability of Sustainable Concrete Subjected to Elevated Temperature – A Review,” Construction and Building Materials, V. 199, Feb. 2019, pp. 435-455. doi: 10.1016/j.conbuildmat.2018.12.040
3. Fernandes, B.; Gil, A. M.; Bolina, F. L.; and Tutikian, B. F., “Microstructure of Concrete Subjected to Elevated Temperatures: Physico-Chemical Changes and Analysis Techniques,” Revista IBRACON de Estruturas e Materiais, V. 10, No. 4, Aug. 2017, pp. 838-863. doi: 10.1590/s1983-41952017000400004
4. Oliveira, L., “Numerical and Experimental Study of the Behavior of Vertical Interfaces of Interconnected Structural Masonry Walls,” University of São Paulo, São Carlos School of Engineering, São Carlos, SP, Brazil, 2014. (in Portuguese)
5. Wang, G.; Zhang, C.; Zhang, B.; Li, Q.; and Shui, Z., “Study on the High-Temperature Behavior and Rehydration Characteristics of Hardened Cement Paste,” Fire and Materials, V. 39, No. 8, Dec. 2015, pp. 741-750. doi: 10.1002/fam.2269
6. Ma, Q.; Guo, R.; Zhao, Z.; Lin, Z.; and He, K., “Mechanical Properties of Concrete at High Temperature—A Review,” Construction and Building Materials, V. 93, Sept. 2015, pp. 371-383. doi: 10.1016/j.conbuildmat.2015.05.131
7. Farage, M. C. R.; Sercombe, J.; and Gallé, C., “Rehydration and Microstructure of Cement Paste after Heating at Temperatures up to 300°C,” Cement and Concrete Research, V. 33, No. 7, July 2003, pp. 1047-1056. doi: 10.1016/S0008-8846(03)00005-X
8. Henry, M.; Suzuki, M.; and Kato, Y., “Behavior of Fire-Damaged Mortar under Variable Re-curing Conditions,” ACI Materials Journal, V. 108, No. 3, May-June 2011, pp. 281-289.
9. Henry, M.; Darma, I. S.; and Sugiyama, T., “Analysis of the Effect of Heating and Re-Curing on the Microstructure of High-Strength Concrete Using X-Ray CT,” Construction and Building Materials, V. 67, Part A, Sept. 2014, pp. 37-46. doi: 10.1016/j.conbuildmat.2013.11.007
10. Pei, Y.; Agostini, F.; and Skoczylas, F., “Rehydration on Heat-Treated Cementitious Materials up to 700°C-Coupled Transport Properties Characterization,” Construction and Building Materials, V. 144, July 2017, pp. 650-662. doi: 10.1016/j.conbuildmat.2017.03.100
11. Li, L.; Jia, P.; Dong, J.; Shi, L.; Zhang, G.; and Wang, Q., “Effects of Cement Dosage and Cooling Regimes on the Compressive Strength of Concrete after Post-Fire-Curing from 800°C,” Construction and Building Materials, V. 142, July 2017, pp. 208-220. doi: 10.1016/j.conbuildmat.2017.03.053
12. Li, Q.; Yuan, G.; and Shu, Q., “Effects of Heating/Cooling on Recovery of Strength and Carbonation Resistance of Fire-Damaged Concrete,” Magazine of Concrete Research, V. 66, No. 18, Sept. 2014, pp. 925-936. doi: 10.1680/macr.14.00029
13. Papayianni, J., and Valiasis, T., “Residual Mechanical Properties of Heated Concrete Incorporating Different Pozzolanic Materials,” Materials and Structures, V. 24, No. 2, May 1991, pp. 115-121. doi: 10.1007/BF02472472
14. de Souza, A. A. A., and Moreno, A. L. Jr., “The Effect of High Temperatures on Concrete Compression Strength, Tensile Strength and Deformation Modulus,” Revista IBRACON de Estruturas e Materiais, V. 3, No. 4, Dec. 2010, pp. 432-448.
15. de Souza, A. A. A., and Moreno, A. L. Jr., “Assessment of the Influence of the Type of Aggregates and Rehydration on Concrete Submitted to High Temperatures,” Revista IBRACON de Estruturas e Materiais, V. 3, No. 4, Dec. 2010, pp. 477-493. doi: 10.1590/S1983-41952010000400007
16. Lin, Y.; Hsiao, C.; Yang, H.; and Lin, Y.-F., “The Effect of Post-Fire-Curing on Strength–Velocity Relationship for Nondestructive Assessment of Fire-Damaged Concrete Strength,” Fire Safety Journal, V. 46, No. 4, May 2011, pp. 178-185. doi: 10.1016/j.firesaf.2011.01.006
17. Xuan, D. X., and Shui, Z. H., “Rehydration Activity of Hydrated Cement Paste Exposed to High Temperature,” Fire and Materials, V. 35, No. 7, Nov. 2011, pp. 481-490. doi: 10.1002/fam.1067
18. Yaragal, S.; Kittur, M.; and Narayan, K., “Recuring Studies on Concretes Subjected to Elevated Temperatures and Suddenly Cooled by Water Quenching,” Journal of Structural Fire Engineering, V. 6, No. 1, 2015, pp. 67-76. doi: 10.1260/2040-2317.6.1.67
19. Akca, A. H., and Özyurt, N., “Deterioration and Recovery of FRC after High Temperature Exposure,” Cement and Concrete Composites, V. 93, Oct. 2018, pp. 260-273. doi: 10.1016/j.cemconcomp.2018.07.020
20. Li, L.; Shi, L.; Wang, Q.; Liu, Y.; Dong, J.; Zhang, H.; and Zhang, G., “A Review on the Recovery of Fire-Damaged Concrete with Post-Fire-Curing,” Construction and Building Materials, V. 237, Mar. 2020, Article No. 117564. doi: 10.1016/j.conbuildmat.2019.117564
21. Li, L.; Zhang, H.; Dong, J.; Zhang, H.; Jia, P.; Wang, Q.; and Liu, Y., “Recovery of Mortar-Aggregate Interface of Fire-Damaged Concrete after Post-Fire Curing,” Computers and Concrete, V. 24, No. 3, 2019, pp. 249-258.
22. Shui, Z.; Xuan, D.; Wan, H.; and Cao, B., “Rehydration Reactivity of Recycled Mortar from Concrete Waste Experienced to Thermal Treatment,” Construction and Building Materials, V. 22, No. 8, Aug. 2008, pp. 1723-1729. doi: 10.1016/j.conbuildmat.2007.05.012
23. Mendes, A.; Sanjayan, J. G.; and Collins, F., “Long-term Progressive Deterioration Following Fire Exposure of OPC versus Slag Blended Cement Pastes,” Materials and Structures, V. 42, No. 1, Jan. 2009, pp. 95-101. doi: 10.1617/s11527-008-9369-7
24. Chromá, M.; Rovnaník, P.; Vořechovská, D.; Bayer, P.; and Rovnaníková, P., “Concrete Rehydration after Heating to Temperatures of up to 1200°C,” International Conference on Durability of Building Materials and Components, Porto, Portugal, 2011, 7 pp.
25. Karahan, O., “Residual Compressive Strength of Fire-Damaged Mortar after Post-Fire-Air-Curing,” Fire and Materials, V. 35, No. 8, Dec. 2011, pp. 561-567. doi: 10.1002/fam.1074
26. Alonso, C., and Fernandez, L., “Dehydration and Rehydration Processes of Cement Paste Exposed to High Temperature Environments,” Journal of Materials Science, V. 39, No. 9, May 2004, pp. 3015-3024. doi: 10.1023/B:JMSC.0000025827.65956.18
27. Suresh, N.; Rao, V.; and Akshay, B. S., “Evaluation of Mechanical Properties and Post-Fire Cured Strength Recovery of Recycled Aggregate Concrete,” Journal of Structural Fire Engineering, V. 13, No. 4, Sept. 2022, pp. 491-505.
28. Crook, D. N., and Murray, M. J., “Regain of Strength after Firing of Concrete,” Magazine of Concrete Research, V. 22, No. 72, Sept. 1970, pp. 149-154. doi: 10.1680/macr.1970.22.72.149
29. Suh, H.; Im, S.; Kim, J.; and Bae, S., “Instant Mechanical Recovery of Heat-Damaged Nanosilica-Incorporated Cement Composites under Various Rehydrations Procedures,” Materials and Structures, V. 55, No. 1, Jan. 2022, Article No. 5. doi: 10.1617/s11527-021-01847-y
30. Shui, Z.; Xuan, D.; Chen, W.; Yu, R.; and Zhang, R., “Cementitious Characteristics of Hydrated Cement Paste Subjected to Various Dehydration Temperatures,” Construction and Building Materials, V. 23, No. 1, Jan. 2009, pp. 531-537. doi: 10.1016/j.conbuildmat.2007.10.016
31. Khoury, G. A., “Compressive Strength of Concrete at High Temperatures: A Reassessment,” Magazine of Concrete Research, V. 44, No. 161, Dec. 1992, pp. 291-309. doi: 10.1680/macr.1992.44.161.291
32. Matesová, D., “Effect of Exposure Time after Heating and w/c Ratio on Residual Strength Concrete: Pilot Studies,” XI International Conference on Ecology and New Building Materials and Products, Czech Republic, 2007, pp. 197-206.
33. Teixeira, G. P., “Análise Experimental da Resistência e do Módulo de Elasticidade pós Incêndio de Concretos com Agregados da Região de Viçosa-MG,” master’s dissertation, Universidade Federal de Viçosa, Viçosa, MG, Brazil, 2018, 73 pp.
34. Suh, H.; Jee, H.; Kim, J.; Kitagaki, R.; Ohki, S.; Woo, S.; Jeong, K.; and Bae, S., “Influences of Rehydration Conditions on the Mechanical and Atomic Structural Recovery Characteristics of Portland Cement Paste Exposed to Elevated Temperatures,” Construction and Building Materials, V. 235, Feb. 2020, Article No. 117453. doi: 10.1016/j.conbuildmat.2019.117453
35. Sarshar, R., and Khoury, G. A., “Material and Environmental Factors Influencing the Compressive Strength of Unsealed Cement Paste and Concrete at High Temperatures,” Magazine of Concrete Research, V. 45, No. 162, Mar. 1993, pp. 51-61. doi: 10.1680/macr.1993.45.162.51
36. Cho, H.-C.; Lee, D. H.; Ju, H.; Park, H.-C.; Kim, H.-Y.; and Kim, K. S., “Fire Damage Assessment of Reinforced Concrete Structures Using Fuzzy Theory,” Applied Sciences (Basel), V. 7, No. 5, May 2017, Article No. 518. doi: 10.3390/app7050518
37. Aseem, A.; Latif Baloch, W.; Khushnood, R. A.; and Mushtaq, A., “Structural Health Assessment of Fire Damaged Building Using Non-Destructive Testing and Micro-Graphical Forensic Analysis: A Case Study,” Case Studies in Construction Materials, V. 11, Dec. 2019, Article No. e00258. doi: 10.1016/j.cscm.2019.e00258
38. Ha, T.; Ko, J.; Lee, S.; Kim, S.; Jung, J.; and Kim, D.-J., “A Case Study on the Rehabilitation of a Fire-Damaged Structure,” Applied Sciences (Basel), V. 6, No. 5, May 2016, Article No. 126. doi: 10.3390/app6050126
39. Ubertini, F., and D’Alessandro, A., “Concrete with Self-Sensing Properties,” Eco-Efficient Repair and Rehabilitation of Concrete Infrastructures, F. Pacheco-Torgal, R. E. Melchers, X. Shi, N. De Belie, K. Van Tittelboom, and A. Sáez, eds., Woodhead Publishing, Sawston, UK, 2018, pp. 501-530.
40. Han, B.; Guan, X.; and Ou, J., “Electrode Design, Measuring Method and Data Acquisition System of Carbon Fiber Cement Paste Piezoresistive Sensors,” Sensors and Actuators A: Physical, V. 135, No. 2, Apr. 2007, pp. 360-369. doi: 10.1016/j.sna.2006.08.003
41. Das, S., and Saha, P., “A Review of Some Advanced Sensors Used for Health Diagnosis of Civil Engineering Structures,” Measurement, V. 129, Dec. 2018, pp. 68-90. doi: 10.1016/j.measurement.2018.07.008
42. Tsangouri, E.; Karaiskos, G.; Aggelis, D. G.; Deraemaeker, A.; and Van Hemelrijck, D., “Crack Sealing and Damage Recovery Monitoring of a Concrete Healing System Using Embedded Piezoelectric Transducers,” Structural Health Monitoring: An International Journal, V. 14, No. 5, Sept. 2015, pp. 462-474. doi: 10.1177/1475921715596219
43. Dong, W.; Li, W.; Tao, Z.; and Wang, K., “Piezoresistive Properties of Cement-Based Sensors: Review and Perspective,” Construction and Building Materials, V. 203, Apr. 2019, pp. 146-163. doi: 10.1016/j.conbuildmat.2019.01.081
44. Ding, S.; Dong, S.; Ashour, A.; and Han, B., “Development of Sensing Concrete: Principles, Properties and Its Applications,” Journal of Applied Physics, V. 126, No. 24, Dec. 2019, Article No. 241101. doi: 10.1063/1.5128242
45. Ubertini, F.; Laflamme, S.; and D’Alessandro, A., “Smart Cement Paste with Carbon Nanotubes,” Innovative Developments of Advanced Multifunctional Nanocomposites in Civil and Structural Engineering, K. J. Loh and S. Nagarajaiah, eds., Woodhead Publishing, Sawston, UK, 2016, pp. 97-120.
46. Han, B.; Ding, S.; and Yu, X., “Intrinsic Self-Sensing Concrete and Structures: A Review,” Measurement, V. 59, Jan. 2015, pp. 110-128. doi: 10.1016/j.measurement.2014.09.048
47. Nalon, G. H.; Ribeiro, J. C. L.; Pedroti, L. G.; de Araújo, E. N. D.; de Carvalho, J. M. F.; Soares de Lima, G. E.; and Şilva de Oliveira, D., “Self-Sensing Mortars: Effect of Moisture and Nanocarbon Black Content,” ACI Materials Journal, V. 118, No. 3, May 2021, pp. 131-141.
48. Sarwary, M. H.; Yıldırım, G.; Al-Dahawi, A.; Anıl, Ö.; Khiavi, K. A.; Toklu, K.; and Şahmaran, M., “Self-Sensing of Flexural Damage in Large-Scale Steel-Reinforced Mortar Beams,” ACI Materials Journal, V. 116, No. 4, July 2019, pp. 209-221. doi: 10.14359/51715581
49. Wang, L., and Aslani, F., “A Review on Material Design, Performance, and Practical Application of Electrically Conductive Cementitious Composites,” Construction and Building Materials, V. 229, Dec. 2019, Article No. 116892. doi: 10.1016/j.conbuildmat.2019.116892
50. Bera, M.; Gupta, P.; and Maji, P. K., “Structural/Load-Bearing Characteristics of Polymer–Carbon Composites,” Carbon-Containing Polymer Composites, M. Rahaman, D. Khastgir, and A. K. Aldalbahi, eds., Springer, Singapore, 2019, pp. 457-502.
51. Pimenta, M. A.; Geracitano, L. A.; and Fagan, S. B., “History and National Initiatives of Carbon Nanotube and Graphene Research in Brazil,” Brazilian Journal of Physics, V. 49, No. 2, Apr. 2019, pp. 288-300. doi: 10.1007/s13538-018-0618-0
52. Kar, P., “Conjugated Polymer Nanocomposites,” Advances in Nanostructured Composites - Volume 1: Carbon Nanotube and Graphene Composites, M. Aliofkhazraei, ed., CRC Press, Boca Raton, FL, 2019, pp. 48-96.
53. Zhao, S.; Zhao, Z.; Yang, Z.; Ke, L. L.; Kitipornchai, S.; and Yang, J., “Functionally Graded Graphene Reinforced Composite Structures: A Review,” Engineering Structures, V. 210, May 2020, Article No. 110339. doi: 10.1016/j.engstruct.2020.110339
54. Dong, W.; Li, W.; Wang, K.; Han, B.; Sheng, D.; and Shah, S. P., “Investigation on Physicochemical and Piezoresistive Properties of Smart MWCNT/Cementitious Composite Exposed to Elevated Temperatures,” Cement and Concrete Composites, V. 112, Sept. 2020, Article No. 103675. doi: 10.1016/j.cemconcomp.2020.103675
55. Nalon, G. H.; Ribeiro, J. C. L.; Pedroti, L. G.; de Araújo, E. N. D.; de Carvalho, J. M. F.; de Lima, G. E. S.; and de Moura Guimarães, L., “Residual Piezoresistive Properties of Mortars Containing Carbon Nanomaterials Exposed to High Temperatures,” Cement and Concrete Composites, V. 121, Aug. 2021, Article No. 104104. doi: 10.1016/j.cemconcomp.2021.104104
56. Jang, D.; Yoon, H. N.; Seo, J.; and Yang, B., “Effects of Exposure Temperature on the Piezoresistive Sensing Performances of MWCNT-Embedded Cementitious Sensor,” Journal of Building Engineering, V. 47, Apr. 2022, Article No. 103816. doi: 10.1016/j.jobe.2021.103816
57. EN 12390-1, “Testing Hardened Concrete - Part 1: Shape, Dimensions and Other Requirements for Specimens and Moulds,” European Committee for Standardization, Brussels, Belgium, 2019.
58. Tian, Z.; Li, Y.; Zheng, J.; and Wang, S., “A State-of-the-Art on Self-Sensing Concrete: Materials, Fabrication and Properties,” Composites Part B: Engineering, V. 177, Nov. 2019, Article No. 107437. doi: 10.1016/j.compositesb.2019.107437
59. Dong, W.; Li, W.; Shen, L.; and Sheng, D., “Piezoresistive Behaviours of Carbon Black Cement-Based Sensors with Layer-Distributed Conductive Rubber Fibres,” Materials & Design, V. 182, Nov. 2019, Article No. 108012. doi: 10.1016/j.matdes.2019.108012
60. Monteiro, A. O.; Loredo, A.; Costa, P. M. F. J.; Oeser, M.; and Cachim, P. B., “A Pressure-Sensitive Carbon Black Cement Composite for Traffic Monitoring,” Construction and Building Materials, V. 154, Nov. 2017, pp. 1079-1086. doi: 10.1016/j.conbuildmat.2017.08.053
61. Li, H.; Xiao, H.; and Ou, J., “Effect of Compressive Strain on Electrical Resistivity of Carbon Black-Filled Cement-Based Composites,” Cement and Concrete Composites, V. 28, No. 9, Oct. 2006, pp. 824-828. doi: 10.1016/j.cemconcomp.2006.05.004
62. Han, B.; Yu, X.; and Ou, J., Self-Sensing Concrete in Smart Structures, Butterworth-Heinemann, Oxford, UK, 2015, 398 pp.
63. da Silva Leite Coelho, P. H.; de Deus Armellini, V. A.; and Morales, A. R., “Assessment of Percolation Threshold Simulation for Individual and Hybrid Nanocomposites of Carbon Nanotubes and Carbon Black,” Materials Research, V. 20, No. 6, Nov.-Dec. 2017, pp. 1638-1649. doi: 10.1590/1980-5373-mr-2016-1084
64. ASTM C595/C595M-20, “Standard Specification for Blended Hydraulic Cements,” ASTM International, West Conshohocken, PA, 2020, 8 pp.
65. Mehta, P. K., and Monteiro, P. J. M., Concrete: Microstructure, Properties, and Materials, 2005, 659 pp. (Portuguese version)
66. Kumar, R.; Singh, S.; and Singh, L. P., “Studies on Enhanced Thermally Stable High Strength Concrete Incorporating Silica Nanoparticles,” Construction and Building Materials, V. 153, Oct. 2017, pp. 506-513. doi: 10.1016/j.conbuildmat.2017.07.057
67. de Assis Oliveira, J.; Ribeiro, J. C. L.; Pedroti, L. G.; de Faria, C. S.; Nalon, G. H.; and de Oliveira Júnior, A. L., “Durability of Concrete After Fire through Accelerated Carbonation Tests,” Materials Research, V. 22(suppl. 1), 2019, Article No. e20190049. doi: 10.1590/1980-5373-mr-2019-0049
68. Sikora, P.; Abd Elrahman, M.; and Stephan, D., “The Influence of Nanomaterials on the Thermal Resistance of Cement-Based Composites—A Review,” Nanomaterials (Basel), V. 8, No. 7, July 2018, Article No. 465. doi: 10.3390/nano8070465
69. Dong, W.; Li, W.; Wang, K.; Han, B.; Sheng, D.; and Shah, S. P., “Investigation on Physicochemical and Piezoresistive Properties of Smart MWCNT/Cementitious Composite Exposed to Elevated Temperatures,” Cement and Concrete Composites, V. 112, Sept. 2020, Article No. 103675. doi: 10.1016/j.cemconcomp.2020.103675
70. Ingham, J. P., “Application of Petrographic Examination Techniques to the Assessment of Fire-Damaged Concrete and Masonry Structures,” Materials Characterization, V. 60, No. 7, July 2009, pp. 700-709. doi: 10.1016/j.matchar.2008.11.003
71. Kim, H. K.; Nam, I. W.; and Lee, H. K., “Enhanced Effect of Carbon Nanotube on Mechanical and Electrical Properties of Cement Composites by Incorporation of Silica Fume,” Composite Structures, V. 107, Jan. 2014, pp. 60-69. doi: 10.1016/j.compstruct.2013.07.042
72. Liu, Q.; Gao, R.; Tam, V. W. Y.; Li, W.; and Xiao, J., “Strain Monitoring for a Bending Concrete Beam by Using Piezoresistive Cement-Based Sensors,” Construction and Building Materials, V. 167, Apr. 2018, pp. 338-347. doi: 10.1016/j.conbuildmat.2018.02.048
73. Nalon, G. H.; Ribeiro, J. C. L.; de Araújo, E. N. D.; Pedroti, L. G.; de Carvalho, J. M. F.; Santos, R. F.; and Aparecido-Ferreira, A., “Effects of Different Kinds of Carbon Black Nanoparticles on the Piezoresistive and Mechanical Properties of Cement-Based Composites,” Journal of Building Engineering, V. 32, Nov. 2020, Article No. 101724. doi: 10.1016/j.jobe.2020.101724
74. de Lima, G. E. S.; Nalon, G. H.; Santos, R. F.; Ribeiro, J. C. L.; de Carvalho, J. M. F.; Pedroti, L. G.; and de Araújo, E. N. D., “Microstructural Investigation of the Effects of Carbon Black Nanoparticles on Hydration Mechanisms, Mechanical and Piezoresistive Properties of Cement Mortars,” Materials Research, V. 24, No. 4, 2021, Article No. e20200539. doi: 10.1590/1980-5373-mr-2020-0539
75. ABNT NBR 13279:2005, “Mortars Applied on Walls and Ceilings – Determination of the Flexural and the Compressive Strength in the Hardened Stage,” Brazilian National Standards Organization, São Paulo, SP, Brazil, 2005, 15 pp.
76. Chung, D. D. L., “Self-Sensing Concrete: From Resistance-Based Sensing to Capacitance-Based Sensing,” International Journal of Smart and Nano Materials, V. 12, No. 1, 2021, pp. 1-19. doi: 10.1080/19475411.2020.1843560
77. Han, B.; Zhang, K.; Yu, X.; Kwon, E.; and Ou, J., “Electrical Characteristics and Pressure-Sensitive Response Measurements of Carboxyl MWNT/Cement Composites,” Cement and Concrete Composites, V. 34, No. 6, July 2012, pp. 794-800. doi: 10.1016/j.cemconcomp.2012.02.012
78. Downey, A.; D’Alessandro, A.; Ubertini, F.; Laflamme, S.; and Geiger, R., “Biphasic DC Measurement Approach for Enhanced Measurement Stability and Multi-Channel Sampling of Self-Sensing Multi-Functional Structural Materials Doped with Carbon-Based Additives,” Smart Materials and Structures, V. 26, No. 6, June 2017, Article No. 065008. doi: 10.1088/1361-665X/aa6b66