Special-Uses-Alkali - Expanded Shale & Clay

4. PRODUCT MATERIAL EXPANSION TESTSAll material tests were measured out to 14-days. The expansion measurements for the 28-dayresults can be found in Appendix C.4.1. Baseline Aggregate TestsThe aggregate sources used for the testing were obtained from Grand Junction Pipe, a concretesupplier located in Grand Junction which is in CDOT’s Engineering Region 3. These aggregateswere chosen for their known high reactivity and because their use is approved for CDOT’s classD mix designs. These aggregates have been processed as a 3/4” rock and a -3/8” gravel blendedto respectively achieve a #67 gradation. The concrete sand is from a different Grand Junction pitalso owned by Grand Junction Pipe where the sand is also known to be very reactive.4.1.1. Coarse Aggregate BaselineThe coarse aggregates were proportioned 70% of 3/4” rock and 30% of -3/8” gravel by weightprior to crushing the gravel. Once this was accomplished, the aggregate was prepared forbaseline testing in accordance with ASTM C 1260. Mortar bars of these materials were cast andplaced in a solution of sodium hydroxide (NaOH), where expansions were measured periodicallyup to the final readings at 14 days and 28 days. The 14-day and 28-day expansions on the coarseaggregate were found to be 0.36% and 0.44% respectively (all expansion results can be found inAppendix C). The CDOT research scope of work dictated 14-day testing. The 28-day testing onall materials was privately funded by FMC-Euclid Chemical (lithium admixture).4.1.2. Concrete Sand BaselineThe concrete sand was also prepared for baseline expansions in accordance with ASTM C 1260.The 14- and 28-day expansions were found to be 0.41% and 0.45% respectively (all expansionresults can be found in Appendix C).4.2. Class F Fly Ash Material TestsSeveral Class F fly ash products were tested in accordance with ASTM C 1567 and evaluatedbased on their ability to resist expansion. The baseline Class F fly ash is produced by the SaltRiver Materials Group. Other Class F fly ash products include Headwaters Incorporated’s Jim17