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12             SECTION 1                                                  ADMINISTRATIVE ISSUES



                        1.3.10 Post-design Tasks
                        1. Responses to contractor’s queries prior to selection.
                        2. Bid approval.
                        3. Construction coordination, fi eld meetings.
                        4. Answering request for information (RFI).
                        5. Design change notices (DCN).
                        6. As-built drawings preparation.

                        1.4  MAINTENANCE OF A SUPERSTRUCTURE
                        1.4.1  Maintenance versus Replacement

                        1. The superstructure is subjected to greater wear and tear from traffic while the substructure is
                            less affected. As a result, substructures are not replaced as often as superstructures. Hence, the
                            life cycle costs and rehabilitation efforts are greater for the superstructure components.
                        2. Replacement of superstructure components is more frequent than for the substructure. This
                            is discussed in detail in a later chapter. Replacement can apply to a component or to the
                            entire superstructure:
                            •  Parapet replacement
                            •   Deck overlay replacement
                            •   Deck joint replacement
                            •   Deck and parapet replacement
                            •   Deck, parapet, and girder replacement
                            •   Deck drainage replacement
                            •  Bearing replacement
                            •   Entire superstructure replacement.
                        3. Maintenance applies to:
                            •   Existing concrete deck repairs
                            •   Deck protective systems
                            •  Deck drainage
                            •  Bearings retrofi t
                            •   Concrete structure repairs
                            •   Steel girders rehabilitation.


                        1.4.2  Parapets and Railing Designs for Crashworthiness
                            A wide variety of railing styles can be seen on bridges throughout the U.S. Railing not
                        meeting current standards requires upgrading, and upgrading of non-crash tested railing is
                        necessary. Parapet repair or replacement using New Jersey Barrier (Figure 1.3) is also required.
                        The following details are required:
                        1. Details showing removal of existing concrete.
                        2. Dimensions for placement of new concrete.
                        3. Treatment of the parapet at expansion joints.
                        4. Parapet transition details.
                        5. Typical sections with reinforcing steel.
                        6. Joint spacing.
                        7. Limits for purpose of measurement and payment.
                        8. Pay item of the work to be included with each item.
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