Preparation of bioadditives for construction: Application of Bacillus subtilis in the self-repair of concrete

Resumen

The present study proposes the use of the bacterium Bacillus subtilis as an innovative solution to improve the self-healing properties of concrete with a design strength of F'c 210 kg/cm². Microbiological analyses were performed with the gram-positive bacterium Bacillus subtilis, along with quality controls of the materials used in the mixture (fine and coarse aggregates). Likewise, mechanical compression and bending tests were carried out on different types of concrete specimens (cylindrical and prismatic) to analyze their ability to self-repair fissures and cracks. The results demonstrated a crack width repair of up to 1.41 mm over a 36-day period. In addition, it was determined that as the curing days increase, the structure is strengthened, increasing its resistance. In summary, the bioprecipitation of calcium carbonate by the bacterium Bacillus subtilis in concrete F'c 210 kg/cm2, is emerging as a sustainable and efficient solution for the self-repair of fissures and cracks in urban and industrial concrete structures.