Bursting and Spalling in Pretensioned U-Beams - Ferguson ...

Figure 2.45 Confining reinforcement provided at end of beamswith both details shown in Figure 2.442.5.2 Best Practices for Minimizing End-Region CrackingThe PCI Committee on Quality Control Performance Criteria put out apublication in 1985 relating precasters’ experience of all sorts of cracks that might form“during casting, stripping or shipment” (p. 4) of pretensioned beams and columns. Thedocument was based on a national survey of PCI members. Causes and effects wereoutlined for a number of crack types, along with preventative and remedial measures.Of interest to the present investigation is the description of “horizontal end cracksin [the] web or flange” (p. 10). The causes of such cracks listed in the document includeimproper design and/or construction, as summarized in Table 2.2. Other causes listed arenot categorized as “improper,” suggesting that even with best practices, some amount ofhorizontal cracking is likely to occur in pretensioned concrete beams. These other causesare listed in Table 2.3.70