Historical Background and Technology of DICON System Sediment Improvement circa 2000

Historical Background and Technology of DICON System Sediment Improvement circa 2000
From the 1990s to the 2000s, the concept of reusing soil and sand generated at construction sites as much as possible and reducing the amount for disposal spread rapidly in the construction field in Japan. This was due to a shortage of land for the disposal of construction soil, soaring industrial waste disposal costs, and the enactment of the Basic Law for Establishing a Recycling-Oriented Society, which called for the reduction of environmental impact. In the past, clayey soil with high water content and sandy soil with unbalanced grain size were considered unsuitable soil and transported to disposal sites for disposal.

At this turning point, a sediment improvement technology called the DICON System was introduced. By automatically measuring and mixing cementitious solidifiers such as lime blast furnace slag powder with excavated soil on site, the system adjusts the strength, permeability, and deformation characteristics of the soil and converts it into a soil material that can be reused as a foundation material for embankments and roadbeds. The mixer and in-line mixing equipment enable continuous and homogeneous improvement, which is revolutionary in that it replaces soil that was previously a waste product with on-site resources.

In the 2000s, environmentally friendly civil engineering became the mainstream, and development of solidification materials with reduced environmental impact, such as hexavalent chromium elution control and pH control, progressed. In addition, risk management methods were introduced to limit the reuse of improved soil, and both quality and safety were improved. In addition, on-site processing of generated soil has reduced the amount of transport, contributing to reductions in CO2 emissions and disposal costs. The system was also applied to the reuse of sedimentary soil from rivers, ports, and dams, and was positioned as an environmentally friendly technology in the era of infrastructure maintenance and management.

The DICON system played an important role at the time as a technology for realizing a resource-recycling society by changing the old concept of treating generated soil as waste.