Below are the books that provided good background for the Skyscraper and Bridges science fair projects.These may be available at your local library. Otherwise the links to Amazon are included.
This is an excellent book for young architects. It contains a brief history of skyscapers as well as a good overview of the technical aspects of building a skyscaper.
A very good "hands-on" science book that shows how to build large structures as well as bridges. Also contains a section on water projects - using locks and dams it explains water flow.
This is another awesome book by Carol Johmann! The book contains some of the history of bridges, how they're built and lots of great pictures and interesting facts.
This is a good science fair book as it shows the forces on a bridge and has practical experiments to do at home to demonstrate the theories explained in the book.