EN15037-1:2008 Beam-and-block floor system: Active Deflection

[Rickyy]

Hi Engineers,

I'm designing a beam-and-block composite floor system as per EN15037-1:2008. I have some questions about calculation of the active deflection.

In the clause E.4.2.3.1, there is a term "m" defined as "the static moment of the total section Sp of the beam relative to the neutral axis of the finished floor system, in mm3: m=Sp(Vi-vi), where Vi and vi are the distances to the lower chord from the neutral axis of the floor section and the neutral axis of the beam section respectively".

I can't really understand this formula and hope for your help:

1. What is the "Sp" used in the formula for calculating "m"? I guess it is the total area of beam section according to the unit (mm3) of "m", but we usually use symbol "A" to represent area of beam. Is there any approach to calculate Sp?

2. Can I assume the neutral axis of the floor section and neutral axis of the beam section as the centroid of the floor system and centroid of the beam?

Thanks.