Simulating Coastal Conditions: Impact of Wetting-Drying Cycles on Concrete Structures

• Zakariya Al Husaini, Material Science, University of Delaware

• Jennifer McConnell, Civil & Environmental Engineering, University of Delaware

In coastal environments, concrete structures are frequently subjected to cyclic wetting and drying due to tidal actions. That is, the periodic rise and fall of the tides result in cycles of submersion and exposure of the structures to saline water. Even though several studies have documented these environmental challenges, the impact on concrete durability is still not well investigated. This study aims to evaluate the effects of such wetting-drying cycles on the structural integrity of concrete. Specifically, it studies the changes in the compressive strength and the microstructural characteristics of concrete exposed to these cycles. Twenty-two cylindrical concrete specimens were prepared and cured under controlled conditions. samples were divided into groups in which they go through different cycles while keeping all other variables fixed. Then, compressive strength tests and microscopic analyses were conducted to assess the mechanical properties and microstructural changes in each specimen. The results show significant variations in compressive strength and microstructure among the different groups, with increased porosity and crack formation in these specimens exposed to more frequent wetting-drying cycles. These findings indicate that environmental exposure has a huge effect on concrete durability, provides valuable insight into the maintenance and design of concrete infrastructure, and emphasizes the need for strategies to improve durability and mitigate environmental impacts.