http://goo.gl/v1nncg for more FREE video tutorials covering Concrete Structural Design
Continuing straight from previous video 2.9, this video at first shows the calculation of compression force working on concrete section in terms of the product of stress and area. Next, the video shows the formula of total actual loads which equals the summation of compression force acting on steel layer 1 plus compression force acting on concrete minus tensile force acting on steel layer 2 minus tensile force acting on steel layer 3. Moving on, the video determines the value of total actual load & draws the point of interactions of different compression and tension forces over the force diagram.
Next, the video takes summation of moment at plastic centroid point of the given section using the obtained values of different compression and tension forces and their respective distance. Thus, the video shows how to find out bending moment at balanced actual point. On hand practice is highly recommended to do with this video to have good grasp on the content of this lesson.