今回の現場適用では、流動化処理土1mShimizu Construction Co., Ltd.
The fluidized processed soil used for backfilling work is a resource-circulating ground material produced by mixing water and cement-based solidifying agents with construction waste, ETC. On the other hand, the cement used as a solidifying agent emits a large amount of CO2 during manufacturing, making the practical application of technologies that contribute to reducing environmental impact an urgent issue.
The biochar used for SUSMICS-S is a powdered form of carbonized wood biomass, which fixes the CO2 absorbed from the atmosphere by trees during their growth as a non-decomposable carbon. By utilizing SUSMICS-S for backfilling work, carbon fixed in the biochar can be stored in the ground, achieving a reduction effect in CO2 emissions associated with construction. Particularly, if the mixing amount of biochar is adjusted so that the amount of fixed CO2 exceeds the emissions from other constituent materials, carbon negativity can be achieved.
In this field application, a carbon-negative specification mixture was adopted that mixes 40 kg of biochar per cubic meter of fluidized processed soil. This biochar fixes an equivalent of 2.3 kg of CO2 per kg, and the storage amount associated with the application of 88 m3 of SUSMICS-S is about 8 tons. The CO2 emissions associated with the construction amount to 4.4 tons from cement-based solidifying materials, while the incidental emissions related to the use of biochar, such as transport and unloading to the plant, are 0.18 tons, resulting in a CO2 emission reduction rate of 178% relative to actual levels.
The manufacturing of SUSMICS-S is completed simply by using existing fluidized processed soil manufacturing equipment and adding powdered biochar and cement-based solidifying agents to construction waste and water. In terms of construction, fluidity equivalent to conventional fluidized processed soil is secured, and quality checks confirmed that the performance meets the requirements for backfilled ground after construction performance tests.
In the future, the application of SUSMICS-S will be expanded to soil-cement walls for temporary earth retention and ground improvement for building foundations, contributing to the realization of a decarbonized society.
