Compressive strength, chloride-ion-penetration resistance, and crack-recovery properties of self-healing cement composites containing cementitious material capsules and blast-furnace-slag aggregates

• Published in: Journal of CO2 utilization Vol. 86; p. 102916
• Main Authors: Lee, Jae-In, Choi, Se-Jin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2024; Elsevier
• Subjects: Blast-furnace-slag aggregate; Capsule; Chloride-ion penetrability; Compressive strength; Self-healing; EDS; CMC; SEM; Self-healing; Capsule; Compressive strength; BFSA; NSA; Chloride-ion penetrability; Blast-furnace-slag aggregate
• ISSN: 2212-9820; 2212-9839
• DOI: 10.1016/j.jcou.2024.102916

Blast-furnace-slag aggregate (BFSA), a by-product of the steel industry, is an eco-friendly natural, aggregate substitute used in mortar and concrete. However, research on self-healing cement composites using BFSA is rare. In this study, the compressive strength, chloride-ion-penetration resistance, and crack-recovery properties of self-healing cement mortar samples prepared using cementitious material capsules (CMC) and BFSA of different ratios were examined and compared to a control sample. The test samples were: Control; C05B00 (5 % CMC and 0 % BFSA); C05B25 (5 % CMC and 25 % BFSA); C05B50 (5 % CMC and 50 % BFSA); C10B00 (10 % CMC and 0 % BFSA); C10B25 (10 % CMC and 25 % BFSA); and C10B50 (10 % CMC and 50 % BFSA). The compressive-strength recovery rate of the control stopped increasing after 28 days and was approximately 110 % on day 56 – that of C10B50 was approximately 121 %, (∼10 % greater than that of the control) and continued to increase even after 56 d. The chloride-ion-penetration resistance of C10B50 was excellent; the 28-day total charge was approximately 5858 C (∼ 40.2 % lower than that of the control). The crack-recovery rates, on day 28, of C05B50 and C10B25 were 71 % and 70 %, respectively (∼ 29–30 % higher than that of the control). •Self-healing cement mortar samples using cementitious CMC, and BFSA examined.•Improvement of mortar compressive strength using cementitious material capsules.•Enhanced mortar compressive-strength recovery rate.•Good chloride-ion-penetration resistance using blast-furnace-slag aggregates.•Superior mortar crack-recovery rates.