A comparative study on dynamic mechanical property and carbonation-hydration kinetics of CO2-cured high performance cementitious composites

Abstract

High performance cementitious composites with limited carbon emission and enhanced dynamic mechanical property is prospective in developing eco-efficient concrete structures that can both sequestrate carbon and suffer impact loads especially for protection facilities. For the aim, static and dynamic mechanical properties of 2% steel fiber (wt.%), 15% silica fume (SF) and 20% fly ash microsphere (FAM) added cementitious composites with CO2 curing treatment were explored. Spilt Hopkinson Pressure Bar testing system (SHPB) coupled with high-speed camera were adopted, carbonation-hydration kinetics in the process of CO2 curing treatment was also focused using a modified isothermal calorimetry method. It was found that carbonated high performance cementitious composites of C-8 showed the highest 1-d and 56-d static compressive strengths, correspondingly with 63.4 MPa and 114.7 MPa, its dynamic compressive strength increased with strain rates, almost reached to 120 MPa at 111 s−1. Drastic carbonation heat flow with peak value of 0.044 W/g and a normally subsequent hydration process were innovatively revealed in the high performance cementitious composites.