Question 1a) What raw material of Portland cement provides the source of aluminum for the formation of C3A?

b) The production of portland cement is responsible for 6% of the world’s CO2

generation. Describe the two sources for the production of CO2 during the firing

of the clinker in the kiln.

c) One of the major phases of cement is written as C2S in cement chemistry notation.

Write the chemical composition of C2S as a chemist would.

Question 2

(1) Describe the hydration reaction of the compound in Portland cement that generates

ettringite.

(2) What are the two basic raw materials used for the manufacture of portland cement?

Question 3

(a) List the four major compounds of portland cement.

(b) Which of these compounds is present in an ordinary portland cement in the largest

amount?

(c) Which of these compounds is considered to be the most undesirable one? Why?

(d) Which of these compounds contributes most to the strength development during

the first few weeks of hydration?

(e) What is the main difference in compound composition of an ordinary Type I and a

high early strength Type III portland cement?

(f) Why is gypsum added to the cement? When is it added?