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A platform for research: civil engineering, architecture and urbanism
Self-healing in metakaolin-based geopolymers with crystalline admixture, expansive agent, and hydrated lime
Abstract This study investigated the self-healing of metakaolin-based geopolymers by incorporation of crystalline admixture (CA), expansive agent (EA), and hydrated lime (HL). Cracks were made in the samples at 3 days of age and their sealing was checked during 112 days of water immersion. The phases formed during self-healing were evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses. The results showed that self-healing did not occur in the mixtures without HL incorporation due to the insignificant calcium content in the material. However, partial self-healing occurred in the 10% HL mixtures. Therefore, the calcium from HL was predominant for the occurrence of self-healing in geopolymers. SEM/EDS analysis showed that calcite formation was the main phase of self-healing. However, C-A-S-H gel and vaterite were also identified as self-healing products. In summary, the results showed that EA is not suitable and CA has the potential to improve self-healing in geopolymers.
Highlights Self-healing in metakaolin-based geopolymer with CA, EA, and HL was investigated. The amount of calcium available in geopolymer was critical to self-healing. Calcite, vaterite, and C-A-S-H gel were identified as products of self-healing. Crystalline admixture promoted matrix densification during self-healing.
Self-healing in metakaolin-based geopolymers with crystalline admixture, expansive agent, and hydrated lime
Abstract This study investigated the self-healing of metakaolin-based geopolymers by incorporation of crystalline admixture (CA), expansive agent (EA), and hydrated lime (HL). Cracks were made in the samples at 3 days of age and their sealing was checked during 112 days of water immersion. The phases formed during self-healing were evaluated by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses. The results showed that self-healing did not occur in the mixtures without HL incorporation due to the insignificant calcium content in the material. However, partial self-healing occurred in the 10% HL mixtures. Therefore, the calcium from HL was predominant for the occurrence of self-healing in geopolymers. SEM/EDS analysis showed that calcite formation was the main phase of self-healing. However, C-A-S-H gel and vaterite were also identified as self-healing products. In summary, the results showed that EA is not suitable and CA has the potential to improve self-healing in geopolymers.
Highlights Self-healing in metakaolin-based geopolymer with CA, EA, and HL was investigated. The amount of calcium available in geopolymer was critical to self-healing. Calcite, vaterite, and C-A-S-H gel were identified as products of self-healing. Crystalline admixture promoted matrix densification during self-healing.
Self-healing in metakaolin-based geopolymers with crystalline admixture, expansive agent, and hydrated lime
Borçato, Allan G. (author) / Medeiros-Junior, Ronaldo A. (author)
2024-02-07
Article (Journal)
Electronic Resource
English
Pre-Hydrated High Alumina Cement Based Expansive Admixture
| British Library Conference Proceedings | 1999