Name: LEONNARDO POSTINGHEL BARRETO
Publication date: 30/10/2025
Examining board:
Name |
Role |
|---|---|
| FRANCIELI TIECHER | Examinador Externo |
| GEILMA LIMA VIEIRA | Presidente |
| RONALDO PILAR | Examinador Interno |
Summary: BARRETO, L.P. Self-healing in concretes containing crystallizing additives and
supplementary cementitious materials: Analysis of chloride migration and
microstructural evolution of self-healing. 2025. Dissertation (Master's Degree in
Civil Engineering) – Postgraduate Program in Civil Engineering, Federal University of
Espirito Santo, Vitória, 2025.
Reinforced concrete structures are prone to cracking, which facilitates the ingress of
aggressive agents, especially chloride ions, thereby reducing durability. This study
aimed to evaluate the self-healing phenomenon in concretes containing silica fume,
blast furnace slag, fly ash, a crystalline admixture, and a reference concrete. To
quantify chloride ion permeability, the electrical migration test according to ASTM
C1202 (2022) was employed. Additionally, qualitative analyses were conducted
through stereoscopic optical microscopy, scanning electron microscopy (SEM) and
energy-dispersive spectroscopy (EDS), in order to identify and characterize the healing
products. The statistical analysis of the results allowed the classification of the
specimens according to ASTM C1202. Concretes with slag and silica fume showed
the lowest charge passed values, demonstrating better performance against chloride
ion penetration. In contrast, the reference concrete and the crystalline admixture
presented higher charge passed values. Microstructural characterization confirmed the
presence of hydration products and precipitates associated with crack closure and
reduced charge passed, particularly in concretes with slag and silica fume. EDS
analyses revealed substantial differences in the products formed inside cracks after
self-healing. The pozzolanic effect proved highly effective through the formation of
secondary C–S–H, while CaCO3 in calcite form was observed in all mixtures with
different morphologies. Magnesium was also detected, mainly in concretes with higher
levels of free calcium hydroxide.
Keywords: self-healing, ASTM C1202, morphology
