Role of cement phases (C3S, C2S, C3A, C4AF) on properties of cement | Cement chemistry by Dr K Mohan скачать в хорошем качестве

Role of cement phases (C3S, C2S, C3A, C4AF) on properties of cement | Cement chemistry by Dr K Mohan

Lecture-12: Role of cement phases (C3S, C2S, C3A, C4AF) on properties of cement | Cement chemistry by Dr K Mohan Dr K Mohan is an internationally renowned and an acclaimed cement scientist. He is a former Director General of National Council for Cement and Building Materials (NCCBM). He holds a Ph.D. degree in Cement Chemistry from University of Aberdeen, Scotland, U.K C3A is responsible for rapid setting, C3S is responsible for quick setting, C2S is responsible for slow setting and C4AF has no role to play in setting of cement. • C3A is responsible for rapid rate of hydration, C3S is responsible for fast rate of hydration, C2S is responsible for slow rate of hydration and C4AF has no role to play in the rate of hydration of cement. • C3A has the highest heat of hydration, followed byC3S and C4AF and C2S has the lowest heat of hydration. • C3Adoes not contribute much to the compressive strength beyond 1 day, C3S is responsible for high early strength. It contributes to high strength up to 14 days,C2Sgives low strength up to 14 days and C4AF has no role to play in early strength development. • C2S is responsible for high later strength. It contributes to high strength beyond 14 days. C3S contributes less to later strength, while both C3A andC4AF have no role to play in later strength development. • C3Ahas poor resistance to chemical attack, C3S has moderate resistance to chemical attack, while both C2S and C4AF have high resistance to chemical attack. • C2S has low drying shrinkage. C3S, C3A and C4AF have no role to play as far as drying shrinkage is concerned. • In addition to four main phases of cement I would like to discuss the role of other constituents of cement. MgO and free lime are responsible for soundness of cement. K2O and Na2O are responsible for alkali - silica reaction. Cl is responsible for corrosion in concrete, Cr2O3, Mn2O3, P2O5, TiO2 may affect strength and colour. Gypsum is used to regulate setting, to control the rate of development of strength at early age and to control drying shrinkage. #Cementchemistry #Clinkerchemistry #Cemenyphase