1) How does aggregate size influence the coefficient of permeability of concrete? List other factors that determine the permeability of concrete in a structure.
2) With respect to frost damage, what do you understand by the term critical aggregate size? What factors govern it?
3) Discuss the factors that influence the compressive strength of concrete exposed to a fire of medium intensity 650 C, short-duration exposure). Compared to the compressive strength, how would the elastic modulus be affected, and why?