Avaliação do desempenho de concretos autocicatrizantes produzidos com materiais cimentícios suplementares submetidos à migração de íons cloreto
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Data
2025-08-14
Autores
Rangel, Heitor Antonio Tschaen
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Universidade Federal do Espírito Santo
Resumo
The presence of cracks, one of the main pathological manifestations of concrete, promotes the appearance of other pathological manifestations. The self-healing of reinforced concrete, which enables the closure of cracks, is seen as a means to extend the service life of structures, generating economic benefits compared to the costs of rehabilitation. Thus, this study aimed to analyze the self-healing phenomenon in different types of concrete with regard to chloride ion migration, carried out through the test governed by ASTM C1202 (2022). In an attempt to identify the compounds formed during the self-healing process, an X-Ray Diffraction (XRD) test was performed using samples taken after the migration test. Additionally, the electrical resistivity test, governed by ASTM C1876 (2024), was conducted, along with the proposal of a visual tool for internal crack analysis, named Colorimetric Analysis Test for Internal Cracking and Self-Healing of Concrete (EACFAIC). For the evaluation, in addition to intact specimens, two ranges of induced cracking were produced in the studied concretes, which were as follows: 1 – Reference concrete with CP V ARI cement; 2 – Concrete with 10% silica fume replacement; 3 – Concrete with 50% fly ash replacement; 4 – Concrete with 75% blast furnace slag replacement; 5 and 6 – Concrete with crystalline additive in two dosages (1% and 5%). The study observed some degree of self-healing in all types of concrete analyzed. However, the highest performances—both in self-healing capacity and in resistance to chloride ion migration (ASTM C1202 test), were achieved with the mineral replacements. These substitutions significantly reduced the passing charge compared to the reference concrete, by 295.91% (Range 1) and 195.49% (Range 2) for blast furnace slag, 116.95% (Range 1) and 117.45% (Range 2) for silica fume, and 130.76% (Range 1) and 64.35% (Range 2) for fly ash. In the volumetric electrical resistivity test governed by ASTM C1876, the concretes with mineral additions confirmed their superiority over the cement-rich mixtures. In the EACFAIC analysis, internal self-healing was implicitly verified in all concretes, corroborating the other test results. The X-Ray Diffraction test identified two main compounds: silicon oxide, originating from the cement, and calcium carbonate, which confirms the hypothesis of self-healing in all concretes
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Concreto , Autocicatrização , ASTMC 1202 , ASTM C1876 , Íons cloreto , Concrete , Self-healing , Chloride ions