Few Questions regarding PSC I-Girder Bridges using Wizard and Construction Stage

1) My first set of questions is about the autogenerated Construction Stages by the Wizard application. I have included below a screen shot of the Construction Stages (please see Figure 1 below). Here are my questions:

A) What is the philosophy behind the assumption of 10-days duration for Stages 1, 2-1 and 3? Does it make any difference if I change them?

The input data of the wizard generates construction stages with the 10-days duration in the model as shown below. 

If you look at Stage 1, prestressed beams and cross-beams are activated. 10 days of duration in Stage 1 means that 10 days have passed before Stage 2-1 starts. The duration of the stage will make concrete beams gain ages. Thus, the change of the values will affect the time-dependent behavior of concrete, i.e. creep, shrinkage, compressive strength of concrete. The value of 10  is just the default value. It should be updated depending on your actual project.

B) I have highlighted Stage 4 in Figure 1 below. In this stage, long-term effects are to be considered (note that I have defined Time Dependent Materials considering Creep and Shrinkage as mentioned in the tutorial video). The issue is that I believe that Stage 4 should be defined before Stage 3. This is my reasoning for this statement: in Stage 3, after composite-actions loads are defined. With the sequence shown in figure below, the bridge will be analyzed based on the bridge stiffness computed in Stage 2 where there is not long-term consideration. I believe that with the sequence shown in figure below, only post construction stage loads such as live loads will be analyzed considering the long-term effects which is not correct. Please note that, according to the AASHOT LRFD 2017 provisions, dead loads after composite actions must be analyzed considering long-term effects and live loads should be analyzed without considering these effects. However, the sequence that the Wizard application generates is in contradiction with this requirement.

2) Figure 2 below shows the definition of the composite section based on the Wizard application and the tutorial video. I have the following questions in this regard:

A) In the video, it is mentioned that we need to input “28” and “7” days for the ages of Part I (i.e., the girder) and Part 2 (i.e., the concrete slab), respectively. What is the philosophy behind these numbers?

This concrete age represents the period of concrete curing before the concrete member starts to resist the loads. During the period of the concrete curing, no stresses are assumed to be introduced in the member by the loads. But the concrete age is necessary to calculate the creep, shrinkage, and compressive strength of concrete. 28 and 7 days are just an example. The user needs to update the values depending on the actual construction.

One of our tutorials is recommended for you to understand the duration and concrete ages. I have attached the tutorial here.

B) Why the parameter “v/s” is always zero even after I “Update Long Term” as shown in Figure 3 below?

This needs to be defined by user. the 'Update Long Term' option is just applied to calculate 'h' value of the section.