Prestessed Box Girders: -…

Prestessed Box Girders:

- On the standard grid arrangement on SS107-13, strands have been removed from the bottom corners of the cross-section and placed at the top of the cross-section, why have these been omitted from the corners?
- Note to designer #4 specifies that the concrete strength at transfer shall not be higher than 38 MPA for prestressed box girders, while the NU girder specifies a concrete strength at transfer of 40 MPa, why are they different (noting that the previous drawings for the prestressed box girders did not specify a minimum concrete transfer strength)?

Prestressed NU Girders:

- For all NU girder sizes, detail B shows the “Top Flange Transverse Rebar Detail with Partial Depth Deck Panels” and indicated hooked rebar at both ends. At the of the girders where the stirrup spacing is close this could lead to rebar congestion. Would it be possible to space hooked bars at every 2nd or 3rd transverse bar rather than at every bar at these locations?
- On SS107-24, the exterior girder cross-section on Section 2 shows the coupler and dowel insert referred to in Note 3 (which indicates that the dowel inserts should be capable of developing a force in tension of 20 kN at SLS). If a higher capacity coupler is available to develop this bar, it would be preferred. This tends to be most important during future jacking for bearing replacement.
- On Section 2 of SS107-24, should the cross-section labelled “INTEGRAL GIRDER” be “INTERIOR GIRDER”?
- On Drawing SS107-22 Girder A, Section 1 the 2-25M [ bars have not been drawn.