Enhancing concrete self-healing capabilities of Bacillus sphaericus spores through the encapsulation in biopolymeric microcapsules

• Published in: Journal of sustainable cement based materials 2024-11, Vol.13 (11), p.1582-1595
• Main Authors: Chuenchom, Chanunda, Intarasoontron, Jirapa, Sorasitthiyanukarn, Feuangthit Niyamissara, Chindasiriphan, Pattharaphon, Jongvivatsakul, Pitcha, Thaiboonrod, Sineenat, Likitlersuang, Suched, Pungrasmi, Wiboonluk, Rojsitthisak, Pranee
• Format: Article
• Language: English
• Subjects: Bacillus sphaericus spores; biopolymeric microcapsules; concrete self-healing; encapsulation; sustainable construction materials
• ISSN: 2165-0373; 2165-0381
• DOI: 10.1080/21650373.2024.2401935

This study examined the encapsulation of Bacillus sphaericus LMG 22257 spores in biopolymeric microcapsules (MCs) for use in cement mortar, with a focus on enhancing self-healing properties. Biopolymers, including alginate (ALG), chitosan (CTS), carboxymethyl cellulose (CMC), and ALG/CMC blends at various ratios, were employed to fabricate the MCs through ionotropic gelation and freeze-drying. The physicochemical properties of MCs, including size, morphology, and swelling behavior under simulated concrete conditions, were assessed. Among these, ALG/CMC-MCs exhibited superior characteristics and demonstrated the highest urea hydrolysis activity when incorporated into the mortar, indicating optimal spore protection. Despite an initial decrease in compressive strength, the ALG/CMC blend with an ALG:CMC mass ratio of 6:4 achieved a crack healing efficiency of 96.7% over 28 days under cyclic wet-dry conditions. These findings highlight the potential of biopolymer encapsulation for embedding functional microorganisms in construction materials, contributing to a more durable and sustainable infrastructure.