Mandatory Construction Temperature as a Specification for Integral Abutment Bridges

Integral abutment bridges (IABs) experience significant cyclic thermal movements induced by fluctuating temperatures. The pattern and maximum value of these movements depend on bridge properties, specific locality of bridge, and the initial temperature when the bridge starts behaving integrally, called the installation temperature or construction temperature (CT). Current practices mostly focus on design temperatures and lack standardized requirements for initial CT. Potential discrepancies may arise because specifications for design temperatures have a tacit assumption that CT is grossly near the middle of the extreme bridge temperatures. However, actual CT can significantly deviate from this tacit assumption during the construction phase because it is mostly not mandated. Consequently, bridge movements may become significantly asymmetrical and unwanted. This study addresses this gap by proposing a practical and easily applicable methodology for setting and mandating CT as a specification to be jointly implemented during in both design and construction of IABs. The output of the proposed method is a tight range for CT, applicable to most days without significant adverse effects in construction scheduling. Attaching the CT as a criterion into design protocols may result in enhanced predictions of thermal displacements and internal forces within IABs. Ultimately, theoretical assumptions can be connected to their practical implementation. As a result, valuable insights and actionable recommendations may be achieved to enhance the reliability, longevity, and efficiency of IABs through overall performance improvements. The methodology presented can also be used for other structures where thermal displacements are of concern.