It's been a while since I did the course, so I've forgotten most of the material and can't give an exact answer, but here's what you should do.
For a.i, asphalt is a composite. The aggregates (or whatever they are) provides hardness and strength while the matrix holds it all together and provides some flexibility.
For a.ii, concrete is used where hardness and durability is required and provide strength to the footing and structural stability. Forgot what the properties of asphalt is that makes it favourable as a covering.
For b.i, take moments around support 2 and work out the force at support 1.
For b.ii, use the method of section.
