[1279] ARAGONITE PRECIPITATION AND MICROSTRUCTURAL DEVELOPMENT IN RECYCLED CONCRETE FINES (RCFs)-BASED CALCIUM CARBONATE CONCRETE (CCC)
Keywords:demolished concrete、heterogeneous precipitation、Ca extraction、wet carbonation、binder distribution
A calcium carbonate concrete (CCC) was made based on recycled concrete fines (RCFs) and CO2. Results showed that the hardening mechanism of RCFs-based CCC is due to the entangled aragonite crystals generated at the contacting areas of particles. A dual precipitation process happened in the CCCmaking process, while the hardening mechanism is ascribed to the precipitation from the Ca(HCO3)2 solution. The RCFs with a cement paste layer structure tend to have a higher affinity for combining the precipitated aragonite crystals.