Addressing the Need for Standardization of Test Methods for Self-Healing Concrete: An Inter-Laboratory Study on Concrete with Macrocapsules
Science and Technology of Advanced Materials 2020
T. Van Mullem, G. Anglani, M. Dudek, H. Vanoutrive, Ģirts Būmanis, C. Litina, A. Kwiecień, A. Al-Tabbaa, Diāna Bajāre, T. Stryszewska, R. Caspeele, K. Van Tittelboom, T. Jean-Marc, E. Gruyaert, P. Antonaci, N. De Belie

Development and commercialization of self-healing concrete is hampered due to a lack of standardized test methods. Six inter-laboratory testing programs are being executed by the EU COST action SARCOS, each focusing on test methods for a specific self-healing technique. This paper reports on the comparison of tests for mortar and concrete specimens with polyurethane encapsulated in glass macrocapsules. First, the pre-cracking method was analysed: mortar specimens were cracked in a three-point bending test followed by an active crack width control technique to restrain the crack width up to a predefined value, while the concrete specimens were cracked in a three-point bending setup with a displacement-controlled loading system. Microscopic measurements showed that with the application of the active control technique almost all crack widths were within a narrow predefined range. Conversely, for the concrete specimens the variation on the crack width was higher. After pre-cracking, the self-healing effect was characterized via durability tests: the mortar specimens were tested in a water permeability test and the spread of the healing agent on the crack surfaces was determined, while the concrete specimens were subjected to two capillary water absorption tests, executed with a different type of waterproofing applied on the zone around the crack. The quality of the waterproofing was found to be important, as different results were obtained in each absorption test. For the permeability test, 4 out of 6 labs obtained a comparable flow rate for the reference specimens, yet all 6 labs obtained comparable sealing efficiencies, highlighting the potential for further standardization.


Keywords
600 Others Self-healing concrete, active crack width control technique, capillary water absorption, machine learning, macrocapsules, polyurethane, Round robin test, self-healing concrete, standardization, water permeability
DOI
10.1080/14686996.2020.1814117
Hyperlink
https://www.tandfonline.com/doi/full/10.1080/14686996.2020.1814117

Van Mullem, T., Anglani, G., Dudek, M., Vanoutrive, H., Būmanis, Ģ., Litina, C., Kwiecień, A., Al-Tabbaa, A., Bajāre, D., Stryszewska, T., Caspeele, R., Van Tittelboom, K., Jean-Marc, T., Gruyaert, E., Antonaci, P., De Belie, N. Addressing the Need for Standardization of Test Methods for Self-Healing Concrete: An Inter-Laboratory Study on Concrete with Macrocapsules. Science and Technology of Advanced Materials, 2020, Vol. 21, No. 1, pp.661-682. ISSN 1468-6996. Available from: doi:10.1080/14686996.2020.1814117

Publication language
English (en)
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