Detecting Solidification Using Moisture Transport from Saturated Lightweight Aggregate

This paper describes how the propensity for early-age shrinkage cracking in low water cement (w/c) concretes has spawned the development of new technologies that can reduce the risk of cracking. One such technology is internal curing. Internal curing uses saturated lightweight aggregate to supply ‘curing water’ to low w/c paste as it hydrates. Significant research has been performed to determine the effects of internal curing on shrinkage and stress development in sealed samples. However, relatively little detailed information exist about how water is released from the lightweight aggregate to the surrounding cement paste. This study examines the timing of moisture release from saturated lightweight aggregate (LWA). Specifically this paper focuses on fluid transport around the time of set. X-ray absorption is used to trace the time at which water moves from the lightweight aggregate to the paste. X-ray observations are compared with results from the Vicat needle, autogenous shrinkage, and acoustic emission tests. These results are contextualized in terms of structure formation and vapor space cavitation in the cement paste.

Language

  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; Photos; References;
  • Pagination: 12p
  • Monograph Title: Transition from Fluid to Solid: Re-Examining the Behavior of Concrete at Early Ages

Subject/Index Terms

Filing Info

  • Accession Number: 01142154
  • Record Type: Publication
  • Report/Paper Numbers: SP-259-6
  • Files: TRIS
  • Created Date: Oct 5 2009 10:26AM