Are they doing it with the intent of getting something out of the country in the mid to long term after the investments are made and the infrastructure is built?
Yes. Who wouldn't? They are not providing financial support! They are investing in the countries and they are building trade patterns that are available there since the west is not taking advantage of them and both the African countries and China are benefiting from these deals so, If they are done in mutual agreement, I see no issue with them.