summary BOOK Understanding the rheology of concrete -- 3

I ask you to give me a page (A4) picking a good topic from a chapter (chapter 3 ,7,or 13) in the book Understanding the rheology of concrete. . I would like you to summarize something from the book that you find interesting and relevant, and describe with your own words what you learnt from reading this chapter,. You can add a hand-made schematic.