engleski

Efficiency of Self-Healing Chemical Additives on the Freeze/Thaw Resistance of Cement Composites

Self-healing of concrete is the process in which the material regenerates itself healing present cracks. It can be either autogenous/natural self- healing or autonomous/artificial self-healing. Autonomous self-healing techniques include the use of crystalline hydrophilic additives, the bacterial method, and the microencapsulation method. Since internal cracking is one of the damage forms that are occurring by freeze/thaw cycles, the idea in this paper was to estimate the effectiveness of artificial self-healing techniques such as crystalline hydrophilic additive and microcapsules on the freeze/thaw resistance of cement composites. The reference mortar mixture, the mortar mixture with crystalline hydrophilic additive as well as the mortar mixture with toluene diisocyanate (TDI) microcapsules (both additives added in 2% by cement weight) were prepared. Hardened mortar samples are subjected to freezing and thawing cycles according to CEN/TS 12390-9:2006 and the amount of scaling material due to freeze/thaw cycles have been measured. The amount of scaling material was lower in case of both mortar mixtures with selfhealing additives than in case of reference mortar mixture which indicate that self-healing chemical additives used here could improve resistance of the cement composites to freeze/thaw cycles.

Crystalline hydrophilic additive, TDI microcapsules, Cement composites, Freeze/thaw resistance

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