Effects of Concrete Added with High Strength Additive on Reduction of Environmental Burden

摘要

It is discussed the effects of a high strength additive on reduction of environmental burden from the viewpoint of LCA in this paper. The high strength additive is mainly consisted of anhydrite and silica powder, the CO_2 primary unit of one is calculated from the power consumption at its production, which amounts to be one order smaller figure compared to that of the cement. This implies to be an effective re-utilizing of industrial wastes and the material itself is considered to be of low environmental burden. It is found that placing of high strength concrete is more effective in reducing environmental burden than repetitive placing of ordinary strength concrete, when highly durable concrete is required. It is revealed that production of high strength concrete by using high strength additive which produce ettringite, can reduce the unit weight of cement for the required design strength, and can reduce environmental burden. It is also found that the compressive strength can be achieved approximately equivalent to that with autoclave curing by using blastfurnace slag cement and ettringite4ormed high strength additive and with only steam curing, and thus that high strength concrete products are possibly produced in this manner. In addition, the method is revealed to be able to reduce the CO_2 primary unit significantly compared to the production with autoclaving, and effective in reducing environmental burden by calculating the CO_2 primary unit required for the production of concrete products.