The effects of modifying additives and chemical admixtures on the properties of porous fresh and hardened cement paste

The effects of additives and admixtures on the macro- and microstructure of porous hardened cement pastes have been identified using X-ray diffraction (XRD), scanning electron microscopy (SEM) and optical microscopy methods. It was fixed, that MBW additive significantly reduces the amount of portlandite due to the active SiO2 in it. Active SiO2 is involved in reactions with the product of hydration of OPC minerals - portlandite and forms germs of calcium hydrosilicates. It leads to increased compressive strength of porous hardened cement paste. The influence of additives and admixtures on the aeration processes and formation of macro- and microstructure of porous hardened cement paste has been explained.