Self-healing performance of reinforced concrete beams using engineered aggregates

• Published in: Engineering structures 2023-11, Vol.295, p.116829, Article 116829
• Main Authors: Pan, Xiaoying, Gencturk, Bora, Aryan, Hadi, Zhuang, Bozhou
• Format: Article
• Language: English
• Subjects: Concrete; Digital image correlation; Durability; Engineered aggregates; Self-healing
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2023.116829

•Self-healing reinforced concrete beams with engineered aggregates were developed and tested.•Mechanical crack-healing is observed for the first time using capsule based healing methods.•Advanced measurement techniques: DIC and UPV were used to confirm self-healing capability. This paper presents a study on the self-healing performance of reinforced concrete (RC) beams using a new approach called engineered aggregates (EA). EA are a type of capsules that release healing agents when the concrete is cracked, without requiring any changes to the conventional concrete preparation methods. In this study, polyurethane (PU) filled EA were added to RC beams with dimensions of 127 mm × 203 mm × 1448 mm and three-point bending tests were conducted. Companion control tests were also conducted on identical beams to compare the self-healing performance of the concrete with and without EA. The development of cracks during the first (initial cracking) and second (after healing) stages was monitored using the digital image correlation (DIC) technique. The addition of EA did not have any impact on the load carrying capacity of the beams, and the DIC results showed that the cracks closed during healing reopened in subsequent testing. Ultrasonic measurements were taken before and after healing to determine the extent of crack healing. The ultrasonic pulse velocity (UPV) measurements and diffusion coefficient calculations showed that the RC beams with PU-filled EA healed the cracks. Water absorption tests were performed to determine the recovery of the original permeability after healing. The study demonstrated the effectiveness of EA in improving the self-healing performance of RC beams and its potential for practical application in the construction industry. This paper is the first member scale study for self-healing concrete with EA, which demonstrated successful filling and bonding of flexural cracks.