Experimental Investigation and Comparative Study on Self-healing Concrete with Superabsorbent Polymer and Bacteria

One of the materials used the most in the building sector is concrete. Concrete cracks often arise when tensions inside the material surpass its strength. Cracks may result from structural stresses, shrinkage, freezing and thawing, and other events. The capacity of concrete to repair cracks on its own, autonomously or autogenously, is known as self-healing concrete. The most well-known methods for achieving efficient self-healing include the use of additional cementing materials, polymers, and microorganisms. This study focuses on the ability of SAP and bacteria to aid in the self-healing of concrete. The chemical used as superabsorbent polymer here is sodium polyacrylate. Bacteria used here is a non-pathogenic bacteria called Bacillus subtilis. For the purpose of this experiment, concrete specimens are made in order to examine the mechanical characteristics and self-healing analysis. Self-healing concrete with 1% of SAP produces improved strength values in comparison to controlled concrete. The self-healing behaviour of concrete with addition of 1% of SAP along with bacteria shows significant healing results. In tests for compression, split tensile, and flexural strength, SAPBC outperforms controlled concrete by 11.20%, 16.55%, and 8.21%, respectively. The crack widths of 0.175, 0.250, and 0.475 mm were healed within 18, 34, and 52 days, respectively. The outcomes of the experiment demonstrate that using bacteria and SAP together has boosted overall strength and successfully repaired cracks.