Abstract
Japan's commitment to growing renewable energy generation from 30 to 45 GW has intensified the focus on offshore wind turbines. Due to the presence of extensive deep-sea waters, the installation of fixed turbines is impractical, making floating structures a more viable option. For supporting structure of said turbines, concrete is preferred over steel as it offers various commercial and technical benefits. However, the response of concrete in offshore environment is still under consideration. When considering rationalisation of construction, pre-casting of modules is one option, however in that case, it is necessary to clarify the behaviour of the joints. This research includes comparative compressive joint behaviour analysis to observe the behaviour of concrete with and without joint under air condition. Additionally, it investigates the shear joint behaviour of concrete floating structure subjected to static loading conditions, both under air & water. In order to keep it simple, only prestressed PC bar is provided between the two concrete modules. The experimental setup under this research includes four cases; Case 1 for Compressive fracture behaviour of monolithic concrete module in air, Case 2 for Compressive fracture behaviour of concrete module with joint in air, Case 3 for Shear fracture behaviour of joint in air and Case 4 for Shear fracture behaviour of joint in water. The experimental results depict that the concrete modules containing joint shows almost the same (approximately 7% lesser) compressive strength than that of monolithic concrete. Additionally, it is observed that the concrete modular joint, exhibit similar joint shear strength (about 6% lesser) in water submerged conditions as compared to under air scenario. The above findings significantly contribute to the growing knowledge on the behaviour of concrete in offshore environments and provide valuable insights into the optimisation of such structures for enhanced durability under harsh conditions.
Keywords
offshore concrete floating structure, compressive strength, joint shear strength, pre-stressed joint.
DOI
10.5703/1288284318155
Recommended Citation
Imran, Maryam; Komatsu, Satoshi; Yamada, Risa; and Matsuo, Toyofumi, "Shear and Compressive Joint Behaviour of Concrete Floating Structure for Offshore Wind Turbine" (2025). International Conference on Durability of Concrete Structures. 5.
https://docs.lib.purdue.edu/icdcs/2025/ddm/5
Shear and Compressive Joint Behaviour of Concrete Floating Structure for Offshore Wind Turbine
Japan's commitment to growing renewable energy generation from 30 to 45 GW has intensified the focus on offshore wind turbines. Due to the presence of extensive deep-sea waters, the installation of fixed turbines is impractical, making floating structures a more viable option. For supporting structure of said turbines, concrete is preferred over steel as it offers various commercial and technical benefits. However, the response of concrete in offshore environment is still under consideration. When considering rationalisation of construction, pre-casting of modules is one option, however in that case, it is necessary to clarify the behaviour of the joints. This research includes comparative compressive joint behaviour analysis to observe the behaviour of concrete with and without joint under air condition. Additionally, it investigates the shear joint behaviour of concrete floating structure subjected to static loading conditions, both under air & water. In order to keep it simple, only prestressed PC bar is provided between the two concrete modules. The experimental setup under this research includes four cases; Case 1 for Compressive fracture behaviour of monolithic concrete module in air, Case 2 for Compressive fracture behaviour of concrete module with joint in air, Case 3 for Shear fracture behaviour of joint in air and Case 4 for Shear fracture behaviour of joint in water. The experimental results depict that the concrete modules containing joint shows almost the same (approximately 7% lesser) compressive strength than that of monolithic concrete. Additionally, it is observed that the concrete modular joint, exhibit similar joint shear strength (about 6% lesser) in water submerged conditions as compared to under air scenario. The above findings significantly contribute to the growing knowledge on the behaviour of concrete in offshore environments and provide valuable insights into the optimisation of such structures for enhanced durability under harsh conditions.
