Alumina, silica, lime and iron oxide are the basic raw material for the
manufacture of Portland cement. The component of Portland cement which
first hardens is
(A) 5CaO. 3 Al2O3
(B) 3CaO. Al2O3
(C) 3CaO. SiO2
(D) 2CaO. SiO2
manufacture of Portland cement. The component of Portland cement which
first hardens is
(A) 5CaO. 3 Al2O3
(B) 3CaO. Al2O3
(C) 3CaO. SiO2
(D) 2CaO. SiO2