construction materials

1- what is necessary to reinforce concrete?
2- what are the ingredients of Portland cement concrete?
3- what is the primary factor that controls the strength of a concrete mix?
4- How is the ultimate strength of a concrete mix determined?
5- A concrete mix designed for an ultimum strength of 4,000 psi in 28 days. what will be its strength in 7 days?
6- generally, what is the cause of shrinkage in concrete?
7- what is the diameter of a no.7 bar?
8- what is the nominal weigh of regular reinforced concrete?
9- what it the yield strength of grade 40 steel? grade 60 steel?
i need the answer for your wone word please