SELF-HEALING CONCRETE: A SUSTAINABLE APPROACH

Abstract

The development of sustainable infrastructure requires construction materials that offer both enhanced service life and minimized maintenance requirements. Conventional concrete is prone to micro-crack formation due to structural loading and environmental weathering, which facilitates the ingress of moisture and aggressive chemicals, leading to durability failure. This paper investigates the performance and mechanism of self-healing concrete as a sustainable approach to mitigate crack propagation. The experimental program evaluates autonomous healing techniques, focusing on bacterial concrete using Bacillus sphaericus incorporated via calcium alginate beads, and chemical healing mechanisms involving sodium silicate microcapsules. Mechanical properties, including compressive strength recovery, split tensile strength, and flexural healing indices, were analyzed at 7, 14, and 28 days of curing. Long-term durability and sealing efficacy were verified through water absorption, chloride penetration resistance, and permeability tests on pre-cracked and healed specimens. The results demonstrate that bacterial self-healing concrete achieves up to 85% crack healing efficiency for crack widths up to 0.35 mm, while simultaneously providing significant strength restoration. Furthermore, the integration of autonomous self-healing technologies contributes to environmental sustainability by reducing the carbon footprint associated with frequent structural repairs, minimizing cement utilization, and enhancing structural longevity.

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