f$\text{'}$c$$is $25$MPa

A concrete column with a cross$-$section of $400$ mm by $400$ mm is cast together with a wall in a building in Sydney, see Fig$\mathrm{.}1.$ The formwork was removed $7$ days after setting, and all the surfaces were left untreated. Knowing that the concrete column will be uniformly loaded with a compressive stress of $0\mathrm{.}3$fc$$ at $28$ days of age, calculate:

a$)$ The total strain caused by shrinkage and creep at $56$ days of age.

b$)$ The creep strain at $84$ days of age when half of the load is applied at $28$ days and the remaining at $56$ days of age. The loading is kept constant after being applied.

c$)$ Why would the creep obtained after a given period of constant sustained loading differ from the creep obtained if the load were applied gradually over the same period?