Mechanical properties, pore structure, and carbon emission of concrete by using coal-fired slag powder to partially replace cement

This study offers a cleaner option for the utilization of coal-fired slag powder (CFP), which can partially (10 %, 20 %, 30 %) replace cement as cementitious material. An analysis carried out on the influence of CFP on the mechanical properties and pore structure of concrete. Meanwhile, the carbon emissions of CFP concrete were evaluated using life cycle assessment (LCA). The results showed that the mechanical properties decline with the CFP admixture increases, the reduction was not significant. The addition of CFP results in an increase in the porosity of concrete, reduces the more harmful pores and increases the harmful pores. The fractal dimension (D_r＞50 nm) is negatively correlated with harmful pores. A porosity-harmful pores strength model and a porosity-D_r＞50 nm strength model were established, with regression coefficients of 0.9862 and 0.9903, respectively. Utilization of CFP to partially replace cement can reduce carbon emissions, when the replacement rate is 30 %, the unit MPa CFP concrete can reduce 0.13 kg carbon emissions.