Special-Uses-Alkali - Expanded Shale & Clay

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