The Korea Institute of Ocean Science and Technology (KIOST; Kim Woong-seo, president) published the results of a study* in an international scientific journal showing that discarded fishing nets and ropes collected from Korea’s coasts and farms can be cut and pulverized and used to reinforce concrete, increasing the durability of concrete structures.

* Composite Structures, September 2022 (Title: Experimental study on strength and flexural toughness properties of waste fishing net hybrid fiber-reinforced cementitious composites)

The study found that crushing discarded fishing nets and ropes and using the resulting fibers to reinforce concrete prevents brittle fractures in concrete structures and reduces changes in length, which is a cause of cracks. The application of this reinforcing technique to marine and harbor concrete structures that are prone to corrosion due to exposure to salt in the marine environment is expected to increase the durability of such structures, thereby extending their lifetimes.

Abandoned fishing gear and buoys account for about 54%* of the total annual amount of marine plastic waste (estimated at about 67,000 tons), causing problems such as marine environmental pollution and ship accidents.

In a bid to address the drastic rise in marine plastic waste year over year, the Korean government established the “First Basic Plan on Marine Waste Management (2021-2030)” last year, and is also planning to introduce a buoy deposit system and real-name fishing gear system.

*National coastal waste monitoring results (March 10, 2021; Ministry of Oceans and Fisheries)

Since 2020, Senior Researcher Park Jun-kil, of the KIOST Coastal Development and Ocean Energy Research Center, and his research team have been developing core technologies for producing structural materials from recycled marine waste as well as related construction methods, including marine waste pre-treatment technology. Based on the similarities between discarded fishing net materials and plastic fibers used to reinforce concrete, the researchers developed reinforcement fibers using abandoned fishing nets that can be used to increase the strength of concrete.

Additionally, they designed and produced a crushing machine capable of cutting and crushing discarded fishing nets and manufactured a recycled fiber-reinforced cementitious composite material, and are also conducting research on the mechanical characteristics of the composite material, such as compression, tension, and bending.

KIOST President Kim Woong-seo said, “It is essential to develop technology for recycling marine debris, which has an extreme impact on the marine environment, into high-value resources. We will strengthen our research capabilities to contribute to extending the lifetimes of harbor structures by recycling not only discarded fishing nets and ropes but all kinds of marine waste into useful resources.”