Structural Evaluation of a Post-tensioned Concrete Bridge Deck: A Non-destructive Testing Approach

Concrete infrastructure in cold climates is susceptible to rapid deterioration due to exposure to a combination of degradation mechanisms that can lead to a reduction in service life. While damage caused by reinforcement corrosion is one of the primary concerns of concrete structures subjected to harsh environmental conditions, its effects are intensified with the presence of frost damage. This is due to the fact that microcracks associated with freezing and thawing cycles (FTC) may accelerate ion transport and corrosion conditions of embedded reinforcement. Moreover, the expected rise in the frequency of FTC in cold climates resulting from climate change will magnify the deleterious effects on concrete infrastructure. Concrete deck slabs are among the critical and vulnerable elements of a bridge that are exposed to the ingress of chloride ions resulting from the use of winter de-icing salts, coupled with FTC. At present, few researchers have explored the synergetic impacts of reinforcement corrosion and FTC on the structural performance of affected prestressed concrete field members. This paper presents the results of the condition assessment of a corroded post-tensioned concrete deck slab element using visual assessment and non-destructive testing (NDT) techniques. The slabs were obtained from a major Canadian bridge after nearly 60 years of service. The findings of this study can ultimately aid in developing more effective maintenance and repair strategies for existing and affected field structures in order to enhance public safety and reduce the economic costs associated with premature structural deterioration.