Don’t we have a consensus and definition (within the AbV and RV) of how steel reinforcing for concrete relates to the concrete elements it is reinforcing? Which IfcRel is to be used? Is the reinforcing meant to aggregated first and then related to the corresponding member or does each piece of reinforcing get related directly to the member?
We need clarity on the BIM for Bridges project…
Looks like this is handled via 4.1.4.1.2 Element Composition - IFC 4.3.2 Documentation
but… is this assuming that the rebar will be aggregated first as an Element Assembly, THEN aggregated to the RC Concrete part (beam/column/slab/etc.)… or each piece of rebar is aggregated directly.
I can’t figure out if it MUST be one way or the other or BOTH are acceptable.
No consensus, but I think we were close Unclear how to relate reinforcing to the element (e.g. slab) · Issue #205 · buildingSMART/IFC4.3.x-development · GitHub
You don’t need to aggregate in an IfcElementAssembly, you can also aggregate into a more semantic type such as Beam / ReinforcingElement. So you get Beam(axis representation) <-- aggregates --> ( Beam(body repr) + Reinforcement(body repr) ) (for example).
If you care deeply about clarity you can create many levels of aggregation indirection in which you maintain proximity in the tree for closely related constructs. The semantics are still somewhat implicit because of the generic relationship usage, although the roles are pretty clear from the element type. I haven’t seen evidence on this whether this deeper nesting is desirable and/or handled well in software.