Abstract
Two innovative additions are considered for the development of self-healing concrete: epoxy-containing silica microcapsules and amine-functionalized nanosilica. The effect of two concentrations of the additions on the microstructure of a cement paste with silica fume is studied. The results indicate a proper dispersion of the additions within the matrix, a pozzolanic reaction induced by nanosilica and the stability of the microcapsules that reliably isolate the epoxy from the paste. As the concentration of additions increases, a preferential orientation of the portlandite phase is observed, together with a decrease of the compressive strength due to the presence of a minor content of macropores and to the low strength of the capsules. The self-healing efficiency is confirmed in concrete specimens for 150 μm wide cracks and a particular concentration of the additions. These results will be essential for the subsequent development of a reliable self-healing concrete based in the epoxy-amine adhesive.
| Original language | English |
|---|---|
| Pages (from-to) | 55-64 |
| Number of pages | 10 |
| Journal | Cement and Concrete Composites |
| Volume | 60 |
| DOIs | |
| Publication status | Published - 1 Jul 2015 |
Keywords
- Cementitious material
- Characterisation
- Microcapsule
- Microstructure
- Nanosilica
- Self-healing