Abstract
Reduction of CO2 emission is one of the most important tasks for the construction industries in many countries, since they cover high ratio in the total emission. On the other hand, reduction of waste emission is another important task for the construction industries in highly populated countries, such as Japan, because of the depletion of landfill sites. Among the whole construction industries, concrete is the most widely and long-term used material. Some of the researchers has qualitatively pointed out that the amount of demolished concrete, especially those used in 1970s, is expected to cause a severe damage on the depletion of landfill sites. To solve the problem, there have been many technical and social proposals. In this paper, to find an optimal material balance and social circumstances for the proposal, we have firstly developed a resource-flow simulation system using the concept of Multi-Agent-System. Secondly, using the system, comparative case studies have been made to examine two typical and prospective proposals; high quality recycled aggregate, and enlargement of building lifetime. The studies have shown that even in the idealistic situation where recycled aggregate is aggressively used despite of its high price, the predicted amount of demolished concrete is overwhelming. The studies have also shown that in the idealistic situation where building lifetime is unrealistically long, the amount of demolished concrete can be reduce on some level.
