Prestressing & Debonding

Prestressing

Specify that the girder will contain pretensioned strands only (conventional design) or post-tensioning tendons with pretensioned strands added for handling and construction loads.

For girders that are designated to contain only pretensioned prestressing (i.e., no post-tensioning), the strand pattern can consist of any combination of straight or draped (harped) strands. Strands can be fully or partially stressed. Both straight and draped strands can also be debonded, which can consist of end or midspan debonding.

Post-tensioned girders can consist of one to four segments of varying lengths with corresponding closure pours used to connect the segments. Segment geometry is defined in the Geometry Dialog Box. Note, however, that since the ducts are normally contained in the web(s) of the girder, any pretensioned strands are typically straight. Hence, pretensioned strands included in post-tensioned girders must be straight in Eriksson Girder. Additionally, the same pattern is assumed for each girder segment.

Debonding

As an alternative to draping strands to control the stresses in the ends of the beam at release, debonding can be used. A debonding pattern can be determined using Eriksson Girder’s fast and efficient design algorithm, or the pattern can be manually designed.