Natural fiber-reinforced shotcrete mixture: Quantitative assessment of the impact of fiber on fresh and plastic shrinkage cracking properties

The plastic stage of the early age of shotcrete life is the foundation of durability. Natural fiber utilization is an effective approach to maintaining the required service life in terms of plastic cracking mitigation. A statistical approach (multiple regression model) was applied to quantify the impact of fiber type, length, and content variables and identify significant predictors throughout mixture optimization. The results indicate that the fiber integration creates a spatial network structure, leading to a significant improvement in the shear resistance of suspensions. This fibrous network can hold plastic cracking formation by forming some initial mechanical strength and a strong matrix that can withstand the shrinkage stress. Therefore, a rheological model was proposed that characterized a fiber mixture as having improved tensile strain capacity owing to viscosity and yield stress development.