Marine and offshore structures often feature difficult to access elements and harsh environmental exposure. This technical session will focus on advanced assessment, inspection, and repair practices for the maintenance of offshore, coastal, and waterfront concrete structures.
Learning Objectives:
(1) Share approaches for structural health monitoring, predictive maintenance, and effective rehabilitation methods to extend service life;
(2) Describe use of advanced technologies and tools, including drones, for the assessment and inspection of structures;
(3) Summarize the use of service life modeling to estimate the remaining service life;
(4) Describe rehabilitation techniques for marine and offshore structures.
Beyond the Damage: Diagnosing and Extending the Life of Marine Concrete Structures
Presented By: Katelyn Low
Affiliation: Wiss, Janney, Elstner Associates, Inc.
Description: Marine concrete structures often operate in highly aggressive environments, which can complicate assessments and repair approaches. In-depth assessments and material evaluation can provide quantitative insight into deterioration cause(s) and extent as well as material durability. Service life modeling can assist in guiding long term repair and mitigation strategies by predicting corrosion initiation and progression, accounting for different repair approaches. A representative case study illustrates how these tools are applied in practice, demonstrating the role of an integrated assessment in identifying distress across elements, evaluating exposure driven degradation, and developing repair programs that can extend the service life in complex marine environments.
Testing and Evaluation of Offshore and Marine Structures: Tools and Techniques of the Future
Presented By: Mohammad Khan
Affiliation:
Description: Nondestructive evaluation (NDE) of 36 piers of a mile-long 60 years old bridge over a major river was performed using drone and crawling robot, which are new and emerging technologies in the inspection and testing of bridges. The deployment of NDE technologies through these platforms is very limited, and this was the first deployment of these technologies at such large scale in a challenging river environment and difficult accessibility conditions. The drone was equipped with high-resolution imaging (HRI) and infrared (IR) thermography cameras and was used to scan all the 36 piers to assess their general overall condition. A quantitative procedure was used to identify 10 piers which showed the most deterioration. An in-depth investigation was conducted on these 10 piers using a crawling robot mounted with ground penetrating radar (GPR), and HRI camera. The results of the drone and robotic NDE compared well with concrete cores retrieved from the piers.
Long-Term Assessment of Concrete Deterioration and Repair Effectiveness in Mid Atlantic Wharfs and Piers
Presented By: Brian Giltner
Affiliation:
Description: Marine and waterfront concrete structures are subject to aggressive environmental exposures that can lead to progressive deterioration and costly repairs over time. This presentation summarizes the review and evaluation of thirteen years of concrete condition, deterioration, and repair data for wharfs, piers, and waterfront structures located throughout the mid Atlantic region. The dataset represents repeated condition assessments performed as part of routine inspection and maintenance programs, providing a unique opportunity to examine long term performance trends in a marine environment.
Structural condition was evaluated through detailed field inspections supplemented by non destructive testing techniques to identify and characterize deterioration mechanisms such as cracking, delamination, corrosion-related distress, and material loss. Visual observations were systematically documented using photographs and field sketches to record the extent, severity, and progression of damage, as well as the type, location, and apparent performance of completed repairs. The presentation highlights observed deterioration patterns, repair frequencies, and recurring distress types, along with qualitative observations on repair durability and effectiveness over time.
Key findings focus on the relationship between exposure conditions, deterioration mechanisms, and repair outcomes, as well as lessons learned regarding inspection practices and documentation methods. The results provide practical insights for owners, engineers, and asset managers seeking to improve condition assessment strategies, prioritize maintenance, and enhance the long-term performance of concrete waterfront infrastructure in the mid Atlantic region.
Managing Nation’s Water Infrastructure Assets
Presented By: Mohammad Shamim Khan, Ph.D., P.E.
Affiliation: PSI
Description: The Nation’s water infrastructure, including dams, locks and levees, which was mostly constructed during the period of 1930’s and 1970’s, has an average age of about 60 years. This water infrastructure was designed for a service life of 50 to 100 years and is now presenting major maintenance, repair, and rehabilitation challenges in the face of uncertain climatic conditions and limited budgets. This also presents an opportunity to learn from the past, take advantage of the technological advancements, and then chart a path forward that restores and renews the existing infrastructure and leads to an economical and longer lasting new infrastructure.
Sustainability of Steel-Reinforced Concrete Seawalls
Presented By: Rodney Meyers
Affiliation: Structural Engineering Institute, ASCE
Description: Climate change is intensifying coastal hazards through increased storm surge, wave action, and chloride exposure, placing greater demands on the durability and resilience of coastal infrastructure. Steel-reinforced concrete seawalls play a critical role in protecting transportation corridors and coastal communities; however, their long-term performance is governed by chloride-induced corrosion of embedded reinforcement in tidal environments.
This study evaluates the sustainability of seawalls through the integration of durability-based design, service life modeling, and embodied carbon considerations. The corrosion process is examined in terms of initiation and propagation phases, with emphasis on chloride diffusion governed by Fick’s Second Law. A 100-year technical service life is targeted using design parameters including low water-to-cementitious materials ratio (w/cm = 0.40), increased concrete cover (3 in.), supplementary cementitious materials (25% fly ash), epoxy-coated reinforcement, and corrosion inhibitors.
Service life predictions were performed using the Life-365 modeling framework in accordance with ACI CODE-365-24. Results indicate a predicted time to first repair exceeding 100 years under tidal zone exposure, demonstrating that appropriate material selection and detailing can significantly enhance durability and reduce lifecycle maintenance. Sensitivity analysis highlights the critical influence of concrete cover and diffusion properties on corrosion initiation.
The study further evaluates sustainability in alignment with ASCE 73-23, balancing service life extension with reductions in embodied carbon. Findings demonstrate that optimizing mixture design and durability measures can simultaneously improve resilience, extend service life, and reduce environmental impact. The results support a performance-based approach to seawall design that enhances community resilience while meeting long-term sustainability goals.