Simulation of prepackaged grout bleed under field conditions.

Details

• Creators:
  Hamilton, H.R. ; Piper, Alexander ; Randell, Alexander ; Brunner, Brett
• Corporate Creators:
  University of Florida. Dept. of Civil and Coastal Engineering
• Corporate Contributors:
  Florida. Dept. of Transportation
• Subject/TRT Terms:
  • Grout
  • Posttensioning
  • Bleeding (Pavements)
  • Portland cement
  • Fillers (Materials)
  • Admixtures
  • Calcium carbonate
  • Tubing
  • Field tests
  • Simulation
• Publication/ Report Number:
  BDK75 977-59
• Resource Type:
  Tech Report
• Geographical Coverage:
  Florida
• Corporate Publisher:
  University of Florida
• Abstract:
  This report contains a summary of the research performed in the area of reproducing and determining the cause of soft ; grout, which has been found in several PT (Post-Tensioned) tubes around the state of Florida. A modified version of the ; Euronorm inclined tube test named modified inclined tube test (MITT) was developed and used to conduct the majority of ; the testing. ; This research was divided into three primary phases. The first was to develop the Modified Inclined Tube Test and ; determine the tendency of prepackaged grout for producing soft grout under laboratory and field test conditions. None of the ; commercially available prepackaged PT grout tested with MITT produced bleed or soft grout when the grout was mixed and ; injected in accordance with manufacturer’s recommendations and tested well before the expiration date printed on the bag. ; A number of variations on MITT were introduced that would simulate more closely the variations that occur in field ; conditions. Additional mix water and residual water in the tube produced soft grout consistently in one of the PT grouts. ; Supplemental tests of fresh grout properties, such as flow cone, unit weight, wet density, pressure bleed, sedimentation, and ; bleed readings on inclined tubes, did not provide indications that soft grout would be formed during MITT. ; The second phase of testing focused on the effect of low-reactivity fillers on the production of soft grout in plain grout ; formulations of portland cement, ground calcium carbonate, and high-range water-reducing admixture (HRWR). Mixtures ; with 45% and 35% additional filler material consistently generated more soft grout than mixtures with 0% additional filler ; for any given water-to-solids ratio (w/s). ; The third and final phase of testing focused on the shelf life of bagged PT grout. Potential modes of degradation included ; pre-hydration of the portland cement and deterioration of the admixtures over time. Three exposure conditions were ; developed that provided a broad spectrum conditioning; these conditions were named Laboratory, Field, and Extreme. PT ; grouts were exposed to these conditions and then tested with MITT for soft grout. Companion particle size analysis (PSA) ; tests were conducted to determine correlation between the production of soft grout and changes in particle size due to pre-hydration. Prolonged storage times increased the susceptibility of prepackaged PT grouts to the formation of soft grout, ; even in favorable environments.
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/27335/dot_27335_DS1.pdf
• File Type:
  [PDF - 9.49 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha256:d584ed52d3a5a4d231552b983fa50874052e3cbf39117f8aa660a8191f2ac0e3