Spring Field Review Site 11 2006MecklenburgBridges over Long Creek and several grade separations at interchange.
~ One of the bents was designed for a post-tensioned integral bent cap. The design required 4 ksi. concrete strength prior to tensioning and 5 ksi. for the final strength. At 21 days the strength was 3.96 ksi. The contractor was waiting to see if 4 ksi would be achieved.
 ~ If design strength is not achieved, additional measures could include:
 ~~ Hiring a consultant to perform a cap rating for standard vehicles and super loads. This would be very helpful to the Bridge Maintenance Unit.
 ~~ Utilizing a lightweight concrete deck.
 ~ The Department should avoid utilizing post-tensioned integral bents, unless absolutely necessary. When necessary, ensure the following:
 ~~ Adherence to all restrictions before the allowing their use.
 ~~ Better consultant coordination during the design phase.
 ~~ The girders control the design and not the bent cap.
 ~ Hammerhead bents on the same project did not look uniform, due to designs by different consultants.
 ~~ Several planned large loop projects planned for the future will raise similar issues.
 ~~ Need more uniformity -- ensure better consultant coordination during the design phase.
 ~ The Construction Unit gave a detailed explanation of the complexities of screeding operations for the following conditions:
 ~~ Heavy skews.
 ~~ Transitioning superelevation on the bridge.
 ~~ Two bridges merging into one bridge.
 ~ The Roadway Unit stated that they try to avoid the conditions stated above whenever possible. However, it is not always possible, especially on big urban interchanges.
Span arrangement and bridge skew issues. Also, constructability issues with the deck and shoulder superelevations as designed.
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