Special-Uses-Alkali - Expanded Shale & Clay

CP-L 4202 1 . Once the effectiveness of Class N and other products evaluated was determined,further testing on a Class D mix design was performed for potential effects on fresh andhardened concrete. The dosage levels of materials to mitigate the expansion less than 0.10% wasdefined from a graph, with an additional one percent added to ensure the mix design wouldindeed have that acceptable expansion property. Testing included entrained air on plasticconcrete, rapid chloride permeability (ASTM C1202-05), and compressive strength at 7, 28, and56 days. In addition to the above testing, CDOT will perform a shrinkage tendency test(American Association of State Highway and Transportation Officials, AASHTO PP 34Restrained Shrinkage Cracking of Concrete (Ring Method)) on selected mix designs in thefuture.The testing will determine the usefulness of Class N fly ash and other materials in mitigatingASR as well as the compressive strength and permeability of the concrete produced with thevarious mitigation materials.1 CP-L 4201 is the CDOT’s ASR expansion test with cement as aggregate baselines. The CP-L 4202 testis the expansion test with the mitigation materials at varying levels of replacement. These CDOT testscorrespond closely to the ASTM C1260 and C1567 tests respectively.2