Service life prediction under chloride-induced corrosion based on rapid chloride penetration test

Abstract

Concrete is a highly heterogeneous composite material that is widely used in the construction industry. At present with the development of new constituent materials, the durability of concrete is the key factor in the service life predictions of structures. The durability of concrete can be defined as its ability to resist against any sort of deterioration which depends on the interaction with the service environment. This project mainly focuses on chloride-induced corrosion and its effects on durability. Rapid Chloride Penetration Test (RCPT) is a rapid indication of resistance for the penetration of chloride ions which depends on the pore structure and pore solution characteristics. This project examines the effect of fly ash content and curing period on RCPT. Results have shown that there is a significant effect of those two factors on RCPT. In addition, relevant compressive strength gain over a period of 28 days is also discussed. Once the RCPT was completed, the chloride profile was obtained by collecting concrete powder samples at different depths. Obtained chloride profiles were fitted into a nonlinear regression analysis, and chloride penetration depths were calculated. Thereafter, the chloride diffusion coefficient was determined from Fick’s second law using chloride profile and chloride penetration depth. It was observed that the RCPT results can be directly used to determine the chloride diffusion coefficient based on the expected chloride concentration as those two parameters show a linear relationship. Finally, a performance-based design approach was proposed to correlate RCPT values with Fib Model code 2010, in order to predict the service life of corrosion affected - uncracked concrete.