Creation of Foundations Contributing to Blue Carbon Ecosystems and Biodiversity through Tidal Flat Development
Toyo Construction and JFE Steel are launching a joint demonstration experiment on April 1, 2026, in the Amagasaki-Nishinomiya-Ashiya Port area to create tidal flats using dredged cohesive soil. The project aims to develop carbon-neutral technologies by utilizing recycled materials like calcia-modified soil to support blue carbon ecosystems and biodiversity.
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- 📰 Published: March 30, 2026 at 20:00
- 🔍 Collected: March 30, 2026 at 22:56 (2h 56m after Published)
Toyo Construction Co., Ltd. (Headquarters: Chiyoda-ku, Tokyo; President and Representative Director: Tatsuyuki Nakamura), in collaboration with JFE Steel Corporation (Headquarters: Chiyoda-ku, Tokyo; President and CEO: Masayuki Hirose), will begin a demonstration experiment on April 1, 2026, in the Marushima district of the Amagasaki-Nishinomiya-Ashiya Port, Hyogo Prefecture, aimed at regenerating and creating foundations that contribute to blue carbon ecosystems and biodiversity through tidal flat development. In this demonstration experiment, the companies will develop technologies that contribute to carbon neutrality by repurposing dredged cohesive soil as material for creating shallow waters*1 and tidal flats, as well as for submerged breakwater materials.
■ Background of the Demonstration Experiment
In recent years, it has become difficult to secure disposal sites for dredged cohesive soil generated from dredging work in shipping channels and anchorages, which is performed to maintain and expand port functions. Consequently, the effective utilization of this soil has become a significant challenge.
■ Overview of the Demonstration Experiment
Dredged cohesive soil contains a high amount of water and is soft, making it difficult to use effectively in its raw state; therefore, strength improvement through dehydration or solidification is necessary. While modification by adding cement is common for solidification, this demonstration experiment also aims to confirm the applicability of using calcia-modified materials*2 to create tidal flats in order to suppress CO2 emissions. Calcia-modified soil*3 will be used as the foundation material for the tidal flats, and calcia artificial stone*4 will be used for the submerged breakwaters.
Calcia-modified soil is attracting attention as a material that can be expected to suppress turbidity and improve the strength of dredged soil, without affecting marine organisms, while also offering potential for improving sediment quality. Furthermore, the design prioritizes the effective use of resources by utilizing recycled and renewable materials; for example, piles and mats made from bamboo—a renewable resource—will be used for slip reinforcement at the base of the submerged breakwaters and for maintenance piers.
■ Future Outlook
In this demonstration experiment, we plan to collaborate with nearby universities to investigate the colonization status of seaweed and seagrass on stone and bamboo materials, as well as the amount of atmospheric CO2 absorbed and sequestered as blue carbon by marine plants. In addition to confirming the manifestation of tidal flat effects such as biodiversity, we are also considering utilizing the site for environmental education and research once these effects are established.
We will continue to advance this demonstration experiment and focus on developing technologies that contribute to the realization of a carbon-neutral society, thereby contributing to the achievement of a sustainable society.
*1 Shallow water areas, mainly facing the coast.
*2 A material produced from converter steelmaking slag (a byproduct of steel manufacturing) that has undergone component management and particle size adjustment.
*3 A material whose physical and chemical properties have been modified by mixing calcia-modified material into soft dredged soil.
*4 Material created by mixing binders such as ground granulated blast-furnace slag into calcia-modified soil to increase its strength to the level of stone, which is then crushed after solidification.
[Figure] Image of artificial tidal flat
[Figure] Image of artificial tidal flat (3D)
[Figure] Image of artificial tidal flat from the seabed (3D)
■ Background of the Demonstration Experiment
In recent years, it has become difficult to secure disposal sites for dredged cohesive soil generated from dredging work in shipping channels and anchorages, which is performed to maintain and expand port functions. Consequently, the effective utilization of this soil has become a significant challenge.
■ Overview of the Demonstration Experiment
Dredged cohesive soil contains a high amount of water and is soft, making it difficult to use effectively in its raw state; therefore, strength improvement through dehydration or solidification is necessary. While modification by adding cement is common for solidification, this demonstration experiment also aims to confirm the applicability of using calcia-modified materials*2 to create tidal flats in order to suppress CO2 emissions. Calcia-modified soil*3 will be used as the foundation material for the tidal flats, and calcia artificial stone*4 will be used for the submerged breakwaters.
Calcia-modified soil is attracting attention as a material that can be expected to suppress turbidity and improve the strength of dredged soil, without affecting marine organisms, while also offering potential for improving sediment quality. Furthermore, the design prioritizes the effective use of resources by utilizing recycled and renewable materials; for example, piles and mats made from bamboo—a renewable resource—will be used for slip reinforcement at the base of the submerged breakwaters and for maintenance piers.
■ Future Outlook
In this demonstration experiment, we plan to collaborate with nearby universities to investigate the colonization status of seaweed and seagrass on stone and bamboo materials, as well as the amount of atmospheric CO2 absorbed and sequestered as blue carbon by marine plants. In addition to confirming the manifestation of tidal flat effects such as biodiversity, we are also considering utilizing the site for environmental education and research once these effects are established.
We will continue to advance this demonstration experiment and focus on developing technologies that contribute to the realization of a carbon-neutral society, thereby contributing to the achievement of a sustainable society.
*1 Shallow water areas, mainly facing the coast.
*2 A material produced from converter steelmaking slag (a byproduct of steel manufacturing) that has undergone component management and particle size adjustment.
*3 A material whose physical and chemical properties have been modified by mixing calcia-modified material into soft dredged soil.
*4 Material created by mixing binders such as ground granulated blast-furnace slag into calcia-modified soil to increase its strength to the level of stone, which is then crushed after solidification.
[Figure] Image of artificial tidal flat
[Figure] Image of artificial tidal flat (3D)
[Figure] Image of artificial tidal flat from the seabed (3D)