Bio-Engineered Fiber-Reinforced Rigid Pavement: A Durability, Strength Recovery and Self-Healing Evaluation
Roberto D. Rosario
a
,
Florante Poso
b
,
Armando Victoria
b
,
Mark de Guzman
c
a FEU Institute of Technology, Sampaloc Manila, Metro Manila, Philippines
b Graduate School, Polytechnic University of the Philippines, Sta. Mesa, Manila, Philippines
c Saint Louis University, Baguio City, Philippines
Lecture Notes in Civil Engineering, (2026), pp. 625-637
Abstract: Fiber-reinforced rigid pavement offers a viable option for sustainable concrete development due to its superior mechanical properties, notably enhanced durability and crack resistance. Nonetheless, cracks remain inevitable. Recent studies have concentrated on harnessing biological mechanisms to introduce self-healing properties to concrete. A particularly promising method employs microorganisms like Bacillus subtilis, which can induce the precipitation of calcium carbonate (CaCO3) when exposed to moisture and air. This microbial-induced calcite precipitation (MICP) efficiently seals cracks, thereby reducing need for manual repairs and extensive maintenance. This study examined the application of 2.36 × 109 CFU of Bacillus Subtilis ATCC 6633 as a bio-admixture in fiber-reinforced concrete pavement. The study assessed the effectiveness of various concentrations. The research concluded that Bacillus subtilis effectively stimulated self-healing of cracks in concrete width of 1–2 mm and material recovery over the seven (7) day period, as verified by Absorption Test (Sorptivity), Ultrasonic Pulse Velocity (UPV), and X-ray Diffraction Analysis (XRD). However, the efficacy of the self-healing process varied based on the concentration of Bacillus subtilis. Higher concentrations (10%) of Bacillus subtilis improve fracture healing but diminished overall material performance. Furthermore, the direct application of 5% Bacillus subtilis proved to be a highly effective variant among the tested formulations, exhibiting an enhancement of flexural strength by 13.13% at 14 days, surpassing the design specifications.