Durability of self-healing concrete

Abstract

Application of self-healing concrete reduces the need for expensive maintenance and repair actions. However, the durability of self-healing concrete has only been scarcely investigated. Here, recent results are presented regarding the resistance of self-healing concrete to chloride ingress. For self-healing concrete with macro-encapsulated polyurethane, chloride profiles and electron probe microanalysis indicated that this mechanism was efficient to reduce the chloride penetration into the crack and from the crack into the concrete matrix [1]. Furthermore, the corrosion behaviour of reinforced concrete specimens subjected to cyclic exposure with a NaCl solution was studied [2]. The electrochemical measurements indicated that autonomous crack healing could significantly reduce the corrosion in the propagation stage. No visual damage could be detected on the rebars after 44 weeks of exposure. On the contrary, cracked specimens without integrated self-healing mechanism, reached a state of active corrosion after 10 weeks of exposure and after 26 weeks clear pitting damage was observed on the rebars. While self-healing by encapsulated polyurethane is complete after one day, bacteria-based products take several weeks to heal a 300 µm crack. Bacterial granules containing denitrifying cultures released nitrite as an intermediate metabolic product which protected the reinforcement during the crack healing process [3].

The Reinforced Spun Concrete Poles under Physical Salt Attack and Temperature: A Case Study of the Effectiveness of Chemical Admixtures

“…Gjorv [ 4 , 5 ] and A. Kudzys, R. Kliukas [ 6 ], to better describe all the factors influencing the durability of concrete, a probability-based durability analysis and performance-based concrete quality control should be implemented. Unfortunately, many authors in their experiments investigate the influence of only one unfavorable factor mainly for vibrated concrete [ 7 , 8 , 9 , 10 ].…”

“…Although there are many papers about concrete durability and the related research about various aggressive actions [ 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ], the majority of them are limited to the research on vibrated concrete. The research on the durability of spun concrete subjected to PSA is seemingly lacking.…”

The Construction of a Footbridge Prototype with Biological Self-Healing Concrete: A Field Study in a Humid Continental Climate Region

“…In addition, the healing process of plain concrete or mortar specimens containing a single crack is commonly studied, while reinforced concrete structures with multiple cracks of different widths, positions and penetration depths are required to consider healing in practice. The self-healing ability of upscaled concrete structures may be inferior in comparison to small laboratory specimens due to the variability of the material parameters and the significant dilution of the healing agent [ 6 ]. Another challenge in upscaling laboratory specimens is the high labor costs of preparing the self-healing agent, especially in the production of BSHC [ 7 , 8 ].…”

“…Moreover, the healing efficiency of BSHC is affected by the concentration of oxygen and both wet-dry and freeze-thaw cycles, all of which depend on the service conditions of the structure [ 13 , 14 ]. Nevertheless, the production and testing of real-scale structural self-healing concrete elements is essential in order to study the effectiveness and longevity of the embedded healing system [ 3 , 6 , 7 ].…”

Autogenous Healing of Cracked Mortar Using Modified Steady-State Migration Test against Chloride Penetration

“…Water permeability or absorption testing techniques, on the other hand, have little effectiveness in determining direct resistance to chloride penetration. Very few articles are available in the literature to deal with the real durability in terms of chloride ingress and among those, a few on real reinforcement corrosion [2,[27][28][29].…”