The cement industry is facing a huge challenge to cut its CO2 emissions as it contributes up to 7% of anthropogenic carbon emissions.Accordingly, the development of novel low carbon manufacturing techniques or alternative cement formulations is of increasing interest and significance.In recent years, concentrated CO2 has been used for curing conventional cement materials instead of traditional moist curing, which led to rapid strength development as well as CO2 sequestration.In particular, novel Ca-or Mg-bearing carbonate-based binders were produced via the accelerated carbonation of reactive MgO cements, which were considered as low-carbon binders.However, limited work has been performed on analyzing the CO2 footprints of these carbonate-bearing binders from a cradle-to-grave point of view.In this study, the CO2 emissions of the carbonate-bearing binders used in concrete blocks, which were produced by carbonating a series of cement blends consisting of Portland cement, MgO, fly ash, and cement kiln dust, were estimated based on the life cycle assessment.For comparison, the CO2 emissions of the hydrated traditional cement materials were also analyzed.Results showed that, for the similar range of mechanical strength, the concrete blocks made with the carbonate-bearing binders via the accelerated CO2 curing emitted less CO2 than those made with traditional Portland cement and with steam curing.This is attributed to the decreased use of Portland cement as well as the CO2 sequestration during the carbonation process.The magnitude of the CO2 reduction of the carbonate binder is dependent on several factors, such as the accelerated curing conditions, mix proportions of raw materials, and so on.The life cycle assessment performed in this study not only provides a basis for better understanding of the design of low-carbon construction materials, but also facilitates to spread the application of the accelerated carbonation technology.