Optimizing the Data Collection for the Service Life Prediction of Concrete Port Infrastructure

For Port Authorities, waterfront assets like quay walls, wharves, and jetties are the pivot of their business cases. The Port’s income will depend on whether the asset is capable of performing adequately during the lease period of the tenant. When not properly maintained, the harsh conditions of the maritime environment will cause major deterioration of the assets. Being able to predict when to intervene with maintenance is key for asset managers. Starting in 2011, the Port of Rotterdam initiated the KMS (Kademuren Modellering Systeem) program, which aimed to assist asset managers in their effort to optimize the prediction of needed maintenance of concrete waterfront structures. The software portion of the KMS program focused on connecting the port legacy system to the service-life prediction model and risk calculation expert applications. At the heart of the KMS, an advanced reactive transport model called STADIUM was used to simulate the exposure to brackish water and seawater to the port infrastructure and predict degradation mechanisms, such as rebar corrosion. To feed the service-life prediction model, information on the in-place concrete is essential. Accordingly, a specific inspection protocol was put in place to collect information relevant to the predictive model. Base information needed to perform service-life predictions includes concrete properties, such as porosity and diffusion coefficient and steel reinforcement cover. This initial KMS inspection program relied heavily on coring and laboratory testing. Yearly inspections allowed gathering information on multiple quay wall sections built at different times and exposed to different environments, ranging from low salinity ones to the seawater of the North Sea. The initial inspection procedure was first optimized by performing statistical analyses of the data gathered in the first six years of the KMS program. This allowed reducing coring operations by half. To refine the information collected on site, coring was replaced using non-destructive tests, which not only helped to compensate for the reduced number of cores but also added new layers of information that greatly enhanced the service-life predictions of the different concrete structures. Non-destructive tests performed on site at this point consisted of corrosion potential and ground-penetrating radar measurements. The third phase of the KMS inspection program is underway and aims to completely eliminate coring activities. Instead, service-life analysis will rely solely on a minimal amount of material collected on site and almost exclusively on non-destructive surface testing. In addition to the tests cited earlier, surface resistivity measurements were added to the program as a means to evaluate concrete properties without extracting cores. The combination of past data with on-site non-destructive testing generates more meaningful data that improves service-life predictions, compared to the initial coring program. This, in turn, leads to a better estimation of the different quay walls’ service-life, which helps managers optimize structure maintenance budgets and extend the service-life of key assets. More importantly, in the ever-present context of global warming, optimizing existing resources instead of building new ones fits perfectly in a sustainable approach to human activities.