Innovative SuperAbsorbent Polymers (iSAPs) to construct crack-free reinforced concrete walls: An in-field large-scale testing campaign

Environmental and economic sustainability of crack mitigation in reinforced concrete with SuperAbsorbent polymers (SAPs)

“…The walls have been cast in the framework of the iSAP project, in which innovative superabsorbent polymers were used for the production of smart concrete mixtures, designed to possess the features of internal curing, self-sealing and self-healing of cracks. It was shown that the thereby developed innovative SAPs added to the concrete mixture were even more efficient in crack mitigation than expected and no cracks were noticed over the complete monitoring period of 9 months (Tenório Filho et al, 2021a) differently from the reference structure where, as shown in Fig. 1, several cracks were already observed.…”

“…In previous laboratory experiments it was furthermore shown that this concrete mixture had the potential to reduce water permeability through cracks of up to 250 µm in width, and increase the resistance to saltscaling under frost attack with a limited reduction in the compressive strength (Tenório Filho et al, 2021a)(Tenório Filho et al, 2020a)(Tenório Filho et al, 2020b)(Tenório Filho et al, 2019)(Tenório Filho et al, 2021b. Tenório Filho, 2021a) 3 Concrete walls repair Nowadays, several methods are available to restore the functionality of damaged concrete structures, with a broad variety of materials and technologies to be used according to the occurred damage. However, it should be emphasized that the design phase of a given structure already takes into account the minimum "deemed to satisfy" requirements to ensure an adequate durability according to the boundary conditions.…”

“…For the purpose of this research a Functional Unit (FU) corresponding to the wall itself was selected with a service life varying from 50 years up to 100 years according to four different scenarios. With regard to the reference structure, since several vertical cracks were already observed after 5 days; and after 1 month the cracks ranged from 50 up to 110 µm width and varying from 870 mm up to 1,880 mm length (Tenório Filho et al, 2021a) , the two above-mentioned repairing activities were taken into account to restore its functionality. The first technique implies the demolition and the reconstruction of the concrete cover with the substitution of the damaged bars with a pre-treatment of the concrete cover substrate prior to the casting of the new layer.…”

“…Figure 1: Cracking pattern of the reference wall at the age of 30 days. Adapted from (Tenório Filho, 2021a) …”

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

“…SAPs are also known as internal curing agents, which means they are helpful for the hydration of unhydrated cement particles in the cement matrix. This hydration can also improve the performance of self-healing of the cracks [22][23][24]. Furthermore, the bacteria-based self-healing process works on the principle that the bacteria available in the concrete behaves as a catalyst and generates a precursor compound that can be used to make an appropriate filler material.…”