The microstructure of self-compacting concrete compared with high performance concrete and traditional concrete

In recent years, self-compacting concrete (SCC) has gained wide application in the construction and infrastructure industry. As for High Performance Concrete (HPC) and traditional concrete (TC), the microstructural properties of SCC are the main factors, which determine the material properties, i.e. the mechanical properties, transport properties and the behaviour when SCC is exposed to the fire. In order to investigate the development of the microstructure of SCC, the microstructural parameters including porosity, pore size distribution and phase distribution are determined by means of mercury intrusion porosimetry and scanning electron microscopy. The thermogravimetric analysis (TGA) and the derivative thermogravimetric analysis (DTG) are used to identify the phase constituents. These parameters are compared with high performance concrete and traditional concrete. The specimens of self-compacting cement paste are made with water/binder ratio 0.41 and 0.48, while the high performance cement paste with w/c 0.33 and traditional cement paste with w/c 0.48. The measurements are performed at different hydration stages, i.e. at 1, 3, 7, 14, 28 and 56 days.