Ferreira Construction needed to meet mass placement temperature specifications and used COMMAND Center to easily monitor concrete temperatures on the Pulaski Skyway Bridge project.

The Goal: Prevent concrete thermal cracking

For large concrete structures that require mass concrete placement, there is great concern that temperature differentials within the structure will lead to thermal cracking ultimately affecting the structure’s durability and safety. 

As concrete sets and gains strength, it gives off heat.  In structures with mass placement, a large amount of heat can be generated.  This heat is greater at the core of the structure and decreases over the distance from the core to its surfaces.  This difference in temperature will lead to internal stresses in the concrete.  If the stresses caused by this temperature difference between the core and the surfaces are greater than the strength of the concrete at any moment in time, the risk for thermal cracking increases.  To minimize an increased risk for thermal cracking, owners, such as state department of transportation agencies, require the contractor to develop a thermal control plan or will specify how to monitor mass placement operations. 

Thermal control plans evaluate risk based on climatic conditions, mix design, curing techniques, and geometry of the structure.  They also provide recommendations of critical locations for monitoring temperatures to ensure the risk for thermal cracking is minimized.  Thermal control plans are developed in-house with the right expertise or subcontracted out to engineers that specialize in the development of thermal control plans.

The Pulaski Skyway Bridge in Kearny, New Jersey required multiple mass placements, so a robust temperature monitoring system was needed to meet the specifications required in the thermal control plan to avoid thermal cracking.

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