Special-Uses-Alkali - Expanded Shale & Clay

3.2. IllinoisThe Illinois Department of Transportation uses AASHTO M321-04 (High-Reactivity Pozzolansfor Use in Hydraulic-Cement Concrete, Mortar, and Grout) for metakaolin after its introductionin 2004, replacing AASHTO M 295. Illinois has no modifications to the standard and can beused as an admixture in concrete mix design.3.3. MontanaMetakaolin must meet the requirements of AASHTO M 295-07 2 . As an admixture, the use ofmetakaolin is limited to 20% replacement of the total cementitious material by weight. Thesource of metakaolin must be on the state’s approved supplier list.3.4. NebraskaNebraska Department of Transportation uses ASTM C 618, for a Class N natural pozzolan. Thepozzolanic content in concrete is limited to 15-25% of the total cementitious material. If Type IPcement is used, the maximum pozzolanic content should not exceed 27%. No modifications tothe standard have been implemented.3.5. NevadaPozzolanic admixtures must conform to ASTM C 618, Class N fly ash or otherwise. The onlymodification being the loss on ignition is limited to 5%. If pozzolans are to be used, thereplacement level may not be more than 20% of the total cementitious material.Type IP cement must have an alkali content of no more than 0.60% by weight. If the alkalicontent of Type IP cement is above the limit, it may still be used if ASTM C 277 testing isperformed and the expansion of the mortar bars is less than 0.05% at 6 months using a selectedreactive aggregate.3.6. New YorkMetakaolin in New York is treated as silica fume (microsilica). The metakaolin must meet therequirements in AASHTO T 307 including the optional chemical and physical requirements;2 AASHTO M295 has been revised for 2007 and currently references ASTM C618.14