Sustainability and performance assessment of binary blended low-carbon concrete using supplementary cementitious materials

This study was carried out to apply low-carbon concrete at actual construction site. For this purpose, there was a necessity for the study that could be tested to adjust the water unit quantity to ensure the constructability as well as the sustainability and performance assessment of concrete according to the quality characteristics of local raw materials. For a designed compressive strength (f_ck) of 24 MPa, which is commonly applied to 29-story apartment structures, the compressive strength properties of binary blended low-carbon concrete were investigated for replacement with ground granulated blast-furnace slag (GGBS) and fly ash (FA). The results of the study were as follows: The compressive strength at 28 days for 5 and 20 °C was linearly reduced by approximately 1.7 and 0.9 MPa when the replacement ratio of GGBS increased by 10% and by 2.5 and 3.8 MPa when the FA replacement ratio increased by 10%, respectively. For a mixing strength of 32.5 MPa at 28 days under 20 °C, the GGBS and FA replacement ratios were below 39.7% and 16.6%, respectively. In terms of environmental effect, when the GGBS and FA replacement ratio increased by 10% each, the life cycle environmental impact of GGBS decreased by 0.6 US$, while FA decreased by 1.1 US$. Through this study, the compressive strength properties of binary blended low-carbon concrete were investigated according to the replacement ratios, and the applicable range of mixing proportions was derived. The results of this study are expected to be utilized as data for the commercialization of low-carbon concretes.