Novel water permeability device for reinforced concrete under load

The presence of cracks in reinforced concrete structures is recognized to increase the penetration of water and aggressive agents into concrete and thus accelerate its deterioration. In order to gain knowledge on the influence of cracking on concrete durability and assess admissible loads to ensure long-term performance of structures, an innovative water permeability device was developed to estimate water flow in plain and cracked reinforced concrete. Permeability measurements were taken simultaneously with the application of a uniaxial tensile load on the testing specimen. The device permitted the estimation of the average stress in the reinforcing bar and the maximum crack opening in the concrete specimen. The experimental program comprised studies on result repeatability and the influence of testing parameters, such as pressure gradient, pressure regulation, loading rate and loading control mode. Test results showed that the modification of the testing parameters had a negligible impact on water permeability. Moreover, correlations were established between the water permeability, the average stress in the steel reinforcement, and the crack opening width in the reinforced concrete. Analysis of the results demonstrated the potential of the research results to improve the design criteria of reinforced concrete at serviceability limit states.