Over 100 Iowa DOT PPCBs with varying lengths and depths were monitored for instantaneous camber measurements. It was observed that instantaneous camber measurements were affected by bed deflection, inconsistent top flange surfaces, and friction between the beam and the bed. Additionally, intermittent long-term camber measurements were conducted for 88 Iowa DOT PPCBs with varying depths and lengths during storage and at the time of erection before/after deck pour up to a period of 460 days. The collected data indicated large scatter in long-term camber measurements due to support conditions and thermal effect. Therefore, identifying the factors influencing instantaneous and long-term camber measurements, additional field measurements and instrumentation were undertaken to quantify these factors as demonstrated below.

Bed Deflection:

String potentiometer attached to the precasting bed at the end of a PPCB

Two PPCB ends in relation to the supports on a precasting bed

Inconsistent top Flange Surfaces:

Inconsistent top flange surfaces on PPCBs- view 1

Inconsistent top flange surfaces on PPCBs- view 2

Friction:

Roller support under a PPCB to eliminate friction- view 1

Roller support under a PPCB to eliminate friction- view 2

Support Conditions:

End of a PPCB on a temporary support
- view 1

End of a PPCB on a temporary support
- view 2

Thermal Effect:

PPCBs instrumentation for thermal effects at different seasons- view 1

PPCBs instrumentation for thermal effects at different seasons- view 2

PPCBs instrumentation for thermal effects at different seasons- view 3