Reduction of concrete´s shrinkage by controlled formation of monosulphate and trisulphate

conference proceedings

English

Concrete’s volumetric changes are natural process caused by silicate minerals’ hydration. These changes can lead to cracking and subsequent destruction of cementitious material’s matrix. In most cases, cracks can be assessed as a negative effect of hydration and in all cases they lead to acceleration of degradation processes. Preventing the formation of these cracks is therefore the main effort. Mono- and trisulfate’s controlled formation in cementitious composite can be classified as a self-healing ability. Its crystal’s growth acts directly against the shrinking tension – this reduces the risk of cracks development. Controlled formation means that these crystals start to grow in the fresh state of material (e.g. concrete) but stops right before it could cause any damage to the hardened material. Waste materials with suitable chemical composition are very attractive precursors because of their added value in the form of landscape pollution’s reduction and, of course, low cost. In this experiment, the possibilities of using the fly ash from fluidized bed combustion as a mono- and trisulfate’s formation additive were investigated. The experiment itself was conducted on cement paste and concrete and specimens were subjected to a thorough analysis of physico-mechanical properties as well as microstructure from the moment of mixing up to 180 days.

shrinkage, monosulphate, trisuplhpate, self-healing, fluidized fly ash, ...

ŤAŽKÝ, M.; HELA, R.; OSUSKÁ, L.; BODNÁROVÁ, L.

28. 11. 2016

TuDelft

Deft, The Netherladn

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