T125: The first three courses in this design series equip the student with fundamental information to begin direct design. This course provides methods to determine prestress levels necessary to satisfy all conditions at the service limit states. All load stages are considered that may be critical during the life of the flexural member. The service limit states control the design of most prestressed concrete members. Except for rare exceptions discussed in the next course on strength limit states, the flexural resistance of prestressed concrete bridges may be significantly larger than required for strength. This results in what is recognized as a large reserve strength compared to other methods of bridge construction. This course explores beam flexural stresses in detail.

After completing this course, the student will be able to:

• Apply Service Limit State principles to calculate stresses in a member and determine prestress level
• Calculate non-transformed and transformed section properties for a non-composite and composite girder
• Include the effect of construction stages on service stress calculations
• Identify allowable stress limits for concrete and prestressing steel materials
• Explain methods for controlling tensile stresses or meeting stress limits in a girder’s end regions