Sorting Activities at Construction Site Succeed in Collecting Approx. 3 Times More Recyclable Waste Plastics
Four companies, including Daiei Kankyo, have succeeded in increasing the amount of recyclable waste plastics from construction sites by approximately three times through sorting activities. The collected plastics were recycled into square lumbers and delivered to the same site, achieving a resource loop.
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- 📰 Published: April 7, 2026 at 22:10
- 🔍 Collected: April 7, 2026 at 13:30
- 🤖 AI Analyzed: April 20, 2026 at 21:37 (320h 6m after Collected)
Four companies—Daiei Kankyo Co., Ltd. (HQ: Kobe, Hyogo; Chairman & CEO: Fumio Kaneko), Resource Circulation Systems Co., Ltd. (HQ: Kitakyushu, Fukuoka; CEO: Takamasa Hayashi), The Konoike-Gumi Co., Ltd. (HQ: Chuo-ku, Osaka; CEO: Hiroki Watazu), and Yagikuma Co., Ltd. (HQ: Fukui, Fukui; CEO: Shinjiro Yagi)—have successfully increased the collection of material-recyclable waste plastics by approximately three times compared to conventional methods. This was achieved by implementing rational and precise sorting rules for waste plastics at a construction site under the 'Artery-Vein Industry Recycling Coordination' by iCEP PLASTICS (*). The collected waste plastics were manufactured into plastic square lumbers and delivered to the same construction site, realizing a resource loop.
■ Background and Challenges
In the construction industry, which accounts for about 20% of all industrial waste in Japan, recycling is a major challenge. Among them, waste plastics discharged from construction sites are often contaminated or mixed with different materials. As a result, thermal recycling, where plastics are incinerated and converted into thermal energy, is the mainstream practice in Japan. However, internationally, thermal recycling tends to be distinguished from recycling in the strict sense because it emits CO₂ during incineration. There is a growing demand for a shift to material recycling, where waste is reused as raw material for new products.
■ Initiatives and Outcomes
The following initiatives were implemented at Konoike-Gumi's logistics warehouse construction site.
1. Formulation and Thorough Enforcement of Sorting Rules
To make sorting easier for construction workers, waste generators and recyclers collaborated to create detailed sorting rules for seven types of waste plastics. These rules were displayed on collection carts and thoroughly communicated on-site. Furthermore, Konoike-Gumi's site staff regularly checked the carts and provided guidance during morning assemblies if any issues were found, thereby raising awareness across the entire construction site.
2. Confirmation of Material-Recyclable Waste Plastic Collection Volume
As a result of sorting waste plastics at the construction site, 59% of the discharged volume was determined to be material-recyclable. This represents a threefold increase compared to the conventional material recycling rate of around 20% for waste plastics at construction sites. Waste plastics deemed difficult to material-recycle were thermally recycled as before.
3. Remanufacturing as Square Lumbers and Delivery to the Construction Site
The material-recyclable plastics were reprocessed and manufactured into plastic square lumbers that can be used at construction sites. By delivering these lumbers to the site where the sorting took place, a resource loop within the site was achieved. Furthermore, by reusing them as recycled products derived from construction sites, it is expected to raise the environmental awareness of all parties involved.