Akademik Veri Yönetim Sistemi
Journal of Sustainable Cement-Based Materials, cilt.13, sa.5, ss.706-725, 2024 (SCI-Expanded)
Crystalline admixture (CA) is an effective self-healing agent for mortar. However, the effects of crackparameters (i.e. crack width and cracking age) and the service environment on the self-healing behavior of CA-containing mortar are not well understood. Herein, the self-healing behavior of mortar containing a self-developed CAwas assessed by testing strength recovery, impermeability recovery, and crack closure in pre-cracked specimens.Three initial crack widths (0.2, 0.3, and 0.4 mm), five cracking ages (3, 7, 14, 28, and 56 days), and four externalexposure conditions (humidity chamber, air exposure, water immersion, and wet-dry cycles) are investigated.Furthermore, the influence of different external conditions on the healing products at the region of crack and the pore structure of hardened paste containing CA are studied. The results show that adding 4.54% CA into mortar allows rapid healing of 300lm-wide cracks. Although wider cracks (400lm) are more difficult to heal, the sorptivity coefficients of the mortars with 400lm-wide cracks after healing decrease. When the cracks are produced at an earlier age, the pre-cracked specimens have higher recovery ratios of strength and impermeability after healing, and the specimens pe-cracked at a later age still have acceptable compressive strengths after healing. The analysis shows thatthe strengths and impermeabilities of pre-cracked mortars containing CA exposed to the four external conditions are all recovered. The best self-healing performance is observed for the specimens exposed to water immersion and wet-dry cycles conditions. Somewhat less good self-healing was observed in the specimens exposed to humid chamber conditionn, while the worst self-healing performance was in the specimens exposed to air exposure condition. This study provides a theoretical basis for the application of novel CAs in cement-based materials.