Dimensionless analysis-based permeability model of reinforced concrete under tension

Water permeability of reinforced concrete is essential for transportation of ingress ions inside concrete structures. The coupling effect of permeability and loading presents a challenge for the experimental simulation of water-permeate reinforced concrete subjected to tension. This renders the development of the model based on dimensionless analysis, using a series of experimental tests from an innovative experimental system that allows simultaneous measurement of permeability and crack width. The experiments focused on both ordinary concrete and high strength concrete under tension. The relationship between permeability and variables such as deformation, diameter of rebars, tensile load, and crack width under tension was formulated through multiple regression analysis using the testing data. The load to deformation characteristics determines the permeability of the concrete under tension. The proposed model accounts for the influence of continuous loading on permeability, as demonstrated by the robust analysis and proposed yield effective point. The robust analysis demonstrates that the diameter of the rebar, load, and crack width exert minimal influence on the permeability of concrete at lower significance levels. However, permeability variations become pronounced from 0.5 threshold, with significant changes observed between 0.5 and 0.9 thresholds. The findings indicate a differential impact of the variables on the permeability of concrete under tension. The yield-effective points delineate the relationship between the rebar diameter, load, and crack-width on the permeability of concrete with a threshold of 0.5, 0.5, and 0.58, respectively. At a threshold of 0.78, higher permeability will occur in the concrete, attributed to the prevalence of deformation. This deformation highlights the parameters with the most significant influence on the permeability of concrete under tension. The robust analysis and yield effective point derivative are useful parameters to measure concrete permeability and evaluate the behavior of the permeability model under tension.