Development and popularization of CO2 Utilizing concrete

KAJIMA CORPORATION

The concept of CO2-SUICOM

Outline

We have been working on the technical development and popularization of ecological concrete that provides efficient use of CO2 (product name: CO2-SUICOM). This concrete is produced by using special materials/methods that can absorb CO2 from various emission sources (such as thermal power stations). Additionally, materials with low CO2 emissions (such as coal ash and blast furnace slag) are used as much as possible so that, together with the CO2 absorption amount, CO2 emissions can be substantially reduced to zero or less. As one type of carbon recycling technology contributing to the realization of a carbon-free society, we are working on reducing the cost of this environmentally friendly concrete and to expand the applicable products in order to further popularize and expand its usage.

Description

We have been working on the technical development and popularization of ecological concrete that provides efficient use of CO2 (product name: CO2-SUICOM (CO2-Storage and Utilization to Infrastructure by Concrete Materials)).
This concrete includes a special admixture that absorbs CO2 as it hardens. During the production process, the concrete is placed in a curing chamber before it has hardened, and CO2 is drawn into the chamber to be absorbed by the concrete. This allows CO2 from various emission sources, such as that emitted by thermal power stations, to be efficiently used.
Due to the special admixture of CO2-SUICOM that absorbs CO2 as the concrete hardens, the amount of cement used is reduced in addition to CO2 absorption. Ordinary concrete block is emitted approximately 300 kg of CO2 from the materials used. Byproducts with low CO2 emissions (such as coal ash and blast furnace slag) are used in CO2-SUICOM as much as possible. CO2 emissions can be reduced to zero or less.
Strength of CO2-SUICOM can be made as strong as ordinary concrete. In addition, SUICOM has features that are not found in general products, such as excellent wear resistance, low efflorescence, and easy plant growth.
This ecological concrete is mainly used for pre-cast concrete such as road and pavement blocks. Various products are already actually being used. Although some of the products are used for long periods, the durability of the concrete is equal to ordinary concrete products.
However, the special materials and methods included in the production process results in a higher cost in comparison with regular concrete products. Moreover, it is difficult to apply to products containing reinforced steel and cast-in-place concrete.
As one type of carbon recycling technology contributing to the realization of a carbon-free society, we will continue technical development to reduce the cost and expand the range of applicable products in order to further increase its use.

Partner(s)

Kajima Corp.: Product development and design
Denka Co., Ltd.: Special admixture development
Landes Co., Ltd.: Production and sales of pre-cast products
The Chugoku Electric Power Co., Inc.: Production verification testing (Thermal power stations)
Mitsubishi Corp.: Business development and marketing