Special-Uses-Alkali - Expanded Shale & Clay

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4.3. Metakaolin ProductsThere were various other products that were evaluated for their resistance to ASR expansion byASTM C 1567. The baseline metakaolin chosen by the Colorado Department of Transportationwas from the Burgess Pigment Company. GCC of America, Holcim, Thiele Kaolin, and WesternPozzolan also submitted materials to be evaluated. Of the group, Western Pozzolan’s product is anatural pozzolan with minor processing. FMC Euclid Chemical and TXI also submittedmaterials, but because of these required modifications to the test procedures, they are discussedin the appendix.4.3.1. Burgess Pigment CompanyThe Burgess Pigment Company provided its metakaolin product called Optipozz as the CDOTchosen baseline metakaolin. This material is white in color and is somewhat less dense thantraditional Class F fly ash or cement with its specific gravity of 2.20. This material was tested atcement replacement levels of 5, 10, and 15%. The Optipozz had expansions of 0.23%, 0.06%and 0.03% respectively after 14 days. This data then gave a successful mitigation level of 9% toutilize in the concrete mix verifications.4.3.2. GCC of AmericaGCC submitted their product called Microsilex. This material is off-white to slightly brown incolor, and claimed to be a material based on natural silica with pozzolanic properties which canimprove the performance and durability of concrete. This material is normally recommended tobe used in replacement levels of 5% to 15%. GCC requested testing this material at 15%, 20%and 25% replacement levels due to the highly reactive aggregate. With these replacement levels,expansions experienced at 14 days are found to be 0.28%, 0.19% and 0.12% respectively.Because the highest replacement level did not reduce the expansion to the required 0.10%, theexpansion graph was extrapolated to give a cement replacement level of 28% to be utilized in themix designs.GCC also requested the Microsilex be combined with Boral’s Monticello fly ash as a ternaryconcrete blend. This test was performed with 10% Microsilex and 10% Boral fly ash, as well as13% Microsilex and 7% Boral fly ash. These blends mitigated the expansions down to 0.05%19
and 0.03% respectively at 14 days. The 10% Microsilex and 10% fly ash blend was utilized forthe mix design in the following phase of testing.4.3.3. HolcimHolcim submitted a product from White Mud Resources. This metakaolin was tested with thereplacement levels of 10, 15 and 20% of cement content. These levels chosen by Holcim weresomewhat conservative in order to ensure the expansions below 0.10% were achieved. Theexpansions at these replacement levels were 0.09%, 0.01% and 0.00% respectively at 14 days.Because the expansions of the bars were at 0.09% at 10% replacement of cement, that value ofcement replacement was used in the mix design.4.3.4. Thiele KaolinThiele Kaolin submitted their Kaorock product. This material is a white in color and issignificantly less dense than cement, with a specific gravity of 2.30. This material was tested at10%, 15% and 20% levels of cement replacement. These replacement levels were far in excessof what was actually needed to get the expansion down below 0.10% at 14 days. The expansionswere 0.02%, 0.02% and 0.01% respectively, indicating that at even 10% replacement, theexpansion was significantly reduced. A replacement level of 10% was used in the mix designs,with possibly 5% being more realistic for future mixes.4.3.5. Western PozzolanWestern Pozzolan submitted a product called Lassenite SR. This is a true natural pozzolan that issomewhat gray and white in color. Lassenite SR is claimed to react with the free lime releasedduring cement hydration forming another compound that is cementious and will reduce thepermeability of the concrete. This product was tested at 5%, 10% and 15% replacement levels ofcement. The expansions at 14 days were 0.35%, 0.24% and 0.11% respectively. To achieve thedesired amount of expansion below 0.10% at 14 days for the mix designs, the graph of percentreplacement level versus expansion was extrapolated to determine the required replacement levelwhich was 16% for the concrete mix designs.20
Page 1 and 2: Report No. CDOT-2008-10Final Report
Page 3 and 4: 1. Report No.CDOT-2008-10Technical
Page 5 and 6: ACKNOWLEDGEMENTSThe staff at J.A. C
Page 7 and 8: Materials other than either Class N
Page 9 and 10: APPENDICESAPPENDIX A - STATE METAKA
Page 11 and 12: CP-L 4202 1 . Once the effectivenes
Page 13 and 14: 1. Lowering the pH of the concrete
Page 15 and 16: Recently, different cement manufact
Page 17 and 18: metakaolin, an 8% replacement of ce
Page 19 and 20: Table 3. KAOROCK ion penetrability.
Page 21 and 22: educe its amount in the cement past
Page 23 and 24: 3.2. IllinoisThe Illinois Departmen
Page 25 and 26: eplacement of portland cement shoul
Page 27: Bridger and Coal Creek power plants
Page 31 and 32: 5. CONCRETE PHYSICAL PROPERTIESAll
Page 33 and 34: 5.3. Metakaolin ProductsAll of the
Page 35 and 36: 5.4.1. HolcimThe GranCem product fr
Page 37 and 38: 6. CONCLUSIONS AND RECOMMENDATIONST
Page 39 and 40: 13. Nasvik, Joe. “Using Metakaoli
Page 41 and 42: note 4 Silicon dioxide (SiO2) plus
Page 43 and 44: APPENDIX C: MORTAR BAR EXPANSION TE
Page 45 and 46: APPENDIX D: TXI LIGHTWEIGHT SAND AD
Page 47 and 48: APPENDIX E: MIX DESIGN INFORMATIONJ
Page 49 and 50: J.A. Cesare & Associates, Inc. / Co

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