Pilot Project for Maximum Heat of Mass Concrete

A 3-D finite element model was developed for prediction of early age behavior of mass concrete footing placed on a soil layer. Three bridge pier footings and one bridge pier cap in Florida were monitored for temperature development. The measured temperatures were compared with the results obtained from the model. Isothermal calorimetry testing was done on the cementitious materials of concrete mixtures to determine the energy released during hydration, which was then converted to temperature rise as inputs for the finite element model. Analysis of behavior of mass concrete placed directly on various types of soil was conducted. A user-friendly software called "DIANA Input File Generator" was developed to provide the needed input files to TNO DIANA software for modeling of typical mass concrete structures such as rectangular footings and columns. The developed 3-D finite element model was found to be effective in predicting the thermal behavior of mass concrete structures at early ages, as the temperature predictions from the finite element modeling showed close agreement with those measured in the field. The in situ condition of the soil was found to have a great effect on the thermal behavior of the concrete footing and determines whether or not an insulation layer would be needed to reduce the temperature difference in the mass concrete and the likelihood for cracking. Dry soil with an R-value of 0.41 or greater (or thermal conductivity of 0.35 J/sec-m-degree C or lower) would provide adequate insulation at the bottom of mass concrete footing in terms of preventing thermal cracking. However, for wet soil where its R-value is less than 0.41, an insulation layer between the soil and the concrete footing would be needed. The development of the user-friendly software "DIANA Input File Generator" provides a convenient and effective tool for generating the needed input files to the TNO DIANA software for analysis of typical mass concrete structures of rectangular footings and columns. It allows engineers and contractors who are not familiar with the detailed inputs to the TNO DIANA software to use this software conveniently and efficiently.

Language

  • English

Media Info

  • Media Type: Web
  • Edition: Final Report
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 168p

Subject/Index Terms

Filing Info

  • Accession Number: 01482122
  • Record Type: Publication
  • Report/Paper Numbers: 00093793
  • Contract Numbers: BDK75 977-47
  • Files: TRIS, ATRI, USDOT, STATEDOT
  • Created Date: May 17 2013 2:52PM