Design and evaluation of high-volume fly ash (HVFA) concrete mixes, report A : evaluation of HVFA cementitious paste and concrete mixtures.

Details

• Corporate Creators:
  Missouri University of Science and Technology
• Subject/TRT Terms:
  • Concrete construction
  • Portland cement
  • Fly ash
  • Mix design
  • Reinforced concrete
  • Recycled materials
  • Economic impacts
  • Cement additives
  • Performance tests
  • Concrete construction
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• Publication/ Report Number:
  TRyy1110
• Resource Type:
  Tech Report
• Geographical Coverage:
  Missouri
• Corporate Publisher:
  Missouri. Department of Transportation
• Abstract:
  In the Paste Screening Study, 25 combinations of five Type I/II portland cements ; and five Class C fly ashes commonly used in Missouri were tested in paste form with no ; chemical or powder additives. Testing procedures included semi-adiabatic calorimetry, ; Vicat setting time, miniature slump, and compressive strength at one and 28 days. The ; two most reactive and two least reactive combinations (defined by one day strengths) ; were further evaluated in the Paste Main Effects Study. Eighty mixtures were examined. ; In the Paste Main Effects Study, the effects of two levels each of WR/HRWR, ; gypsum, calcium hydroxide (lime), rapid set cement (RSC), and gypsum-lime, and ; gypsum-RSC were determined. Except for the WR/HRWR dosage level experiment, all ; other mixtures contained a low WR/HRWR dosage. Except for the gypsum level ; experiment, all other mixtures contained 4% gypsum. The lime levels were 5 and 10% ; and the RSC levels were 10 and 20%. All percentages are by mass of fly ash. Sixty-four ; mixtures were examined. ; The objective of the Concrete Properties Study was to scale up from paste to ; concrete the most promising powder additive combinations and then evaluate the ; mixtures in terms of plastic and hardened properties. Thus the mixture matrix included ; ordinary portland cement (OPC)-fly ash blends at two levels (same as in the Paste Main ; Effects Study) and fly ash at three levels (zero, 50 and 70%). WR dosage (nominal ; dosage), gypsum content (4%), lime content (10%), and RSC content (20%) were held ; constant. Ten concrete mixtures were evaluated. ; At the 50% fly ash level, one day strengths were low no matter which powder ; additives was used, but good strengths were achieved by day 3. At the 70% fly ash level, the concrete was weaker than at zero and 50% fly ash, but reasonable strengths were ; reached at 28 days. At 50% fly ash, abrasion resistance was somewhat lower. At 70% the ; effect was much worse. In regard to drying shrinkage, it appears that HVFA mixtures ; shrink less than their OPC counterparts. In a comparison to OPC mixtures, rapid chloride ; permeability (RCP) was lower for 50% fly ash mixtures, but 70% fly ash mixtures are ; more permeable. All HVFA mixtures had greater freeze-thaw Durability Factors than the ; OPC mixtures, and were at 93 or above. However, all fly ash mixtures did poorly in ; regard to salt scaling. Reaction time (calorimeter curve time, setting time, stiffening time) ; varied as a function of characteristics of the OPC and fly ash in conjunction with each ; other, type and level of powder additives used, dosage of WR/HRWR, and the type of ; test method used for evaluation.
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• Format:
  PDF
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/25526/dot_25526_DS1.pdf
• File Type:
  [PDF - 5.53 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:d6b999e103c824a1e66311e25e404dd7fec54c9bd46881eb8ba883e20195e2bde21a7f85a224627d6ad2a1c63f2bad5bab60b443c52ff287b8483439714b2b1f