Enhancing Freeze-Thaw Resistance of Tennessee Concrete Mixes through Improved Air Void Testing

The quality of the air void system in concrete is critical for the freeze-thaw durability and service life of concrete structures. In Tennessee, the current Tennessee Department of Transportation (TDOT) specification only specifies the air content for fresh concrete mixes. Currently, the most widely used methods to evaluate the freeze-thaw durability and the air void system of concrete include ASTM C666 test, ASTM C457 test, and Air Void Analyzer (AVA) test. However, these test methods are unsuitable for fresh concrete mixes in the field for QC/QA purposes. This study investigates the applicability of Super Air Meter (SAM) to TDOT concrete mixes and the suitability of SAM number as a QC/QA tool for freeze-thaw resistance and determines the acceptance criterion for the SAM number if it can be adopted for QC/QA purposes. The results show that for TDOT concrete mixes, only the fresh air content requirement (e.g., 4%~8% for Class A, 4.5%~7.5% for Class D) does not necessarily guarantee high quality of air void system and enough freeze-thaw resistance. SAM number shows a decreasing trend with the increase of air content of fresh concrete. There is a good correlation between SAM number and freeze-thaw durability factor/spacing factor for TDOT concrete mixes. Therefore, using air content and SAM number as a QC/QA tool for TDOT concrete mixes is feasible. From a conservative perspective, 0.2 can be used as the threshold of SAM number to ensure TDOT concrete mixes have satisfactory freeze-thaw resistance. In addition, it is also feasible to use 0.3 as the upper limit of SAM number for TDOT concrete mixes.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Photos; References; Tables;
  • Pagination: 68p

Subject/Index Terms

Filing Info

  • Accession Number: 01846733
  • Record Type: Publication
  • Contract Numbers: RES2020-09
  • Created Date: May 24 2022 10:22AM