Hybridized bio-based repair mortars: Effects on mechanical, self-healing, and cost performance via novel generalized indexing

This study delves into enhancing the mechanical properties and cost-effectiveness of self-healing cementitious materials through detailed investigation. It conducts a thorough characterization of different hybridized self-healing repair mortars, comprising a laboratory-prepared mortar and two commercial non-self-healing mortars, along with a commercial ready-mix self-healing repair mortar. By incorporating bacteria at varying levels of 1.5 % and 2.5 % as cement replacements, the study aims to reduce costs associated with the self-healing process. Additionally, a sustainability-focused hybridization is performed by combining the ready-mix self-healing repair mortar with the weakest of the three parent mixes. The research evaluates the impact of mortar composition on mechanical properties, particularly concerning the optimal proportion of self-healing agents to achieve maximum strength. Notably, the crack healing efficiency of bacterial-incorporated specimens exhibits significant effectiveness. The correlation between the mechanical properties of intact specimens and their crack healing efficacy is explored, uncovering the potential for creating an outstanding self-healing repair mortar with exceptional healing efficiency and robust mechanical performance. Furthermore, a comparative cost analysis and an overall performance evaluation using the Generalized Performance Index (GPI) demonstrate the feasibility of striking a balance between self-healing material costs and desired performance outcomes through the strategic approach of hybridization.