The reduction of CO2 emissions is an important issue concerning global climate change. In Japan, CO2 emission owing to cement production comprises approximately 3% of the total CO2 emissions. This study reports a technology system that can substantially reduce the emitted energy and CO2 from cement production using energy CO2 minimum (ECM) cement. Herein, ECM cement with a slag content of over 60% was developed and its applications for concrete structures and ground improvement were studied. The CO2 produced when producing the newly developed cement was 70% and 40% less than the CO2 produced when producing ordinary Portland cement and conventional blast-furnace cement type B, respectively. This study also presents laboratory test results of ground improvement using ECM cement. In the laboratory test, the hydration heat characteristics, compressive strength, and dissolution of hexavalent chromium Cr(VI) of improved soils were investigated. Thereafter, the ECM cement was applied for the ground improvement of a construction project in the Osaka Bay area, Japan. The strength and deviation of strength of the improved soil on site were also studied, and based on the laboratory and in situ results, the ECM cement was considered to be suitable for ground improvement.
Subjects: ground improvement, CO2 emission, blast furnace slag
Author: Takao Kono and Masamichi Aoki, Executive Manager
Publisher: DFI, EFFC