Optimizing High-Volume Cement Replacement with Binary and Ternary Blended Binders Incorporating Ground Glass Pozzolan

This study explores high-volume cement replacement using binary and ternary blended binders incorporating ground-glass pozzolan (GP). Binary blends of GP and portland cement (PC) or portland limestone cement (PLC) were studied at cement replacement levels up to 70%. Ternary blended binders incorporating fly ash, slag cement (SC), calcined clay (CC), ground bottom ash, fluidized bed combustion ash, or volcanic ash were also studied. The performance of the blended binders was measured by the modified R3 test, ambient-temperature heat release, and the strength activity index test. Binary blends performed well up to 50% cement replacement, above which the deficit of calcium hydroxide (CH) limited the pozzolanic reaction with GP. Similarly, ternary blends with other pozzolans created competition for a limited supply of CH, resulting in poor performance. However, ternary blends with SC performed well due to synergy between the pozzolanic activity of GP and the hydraulic activity of slag. An optimal balance of performance and GP utilization was achieved using a ternary blend of 30% PC or PLC, 30% GP, and 40% SC. The strength activity index of blended binders was well correlated with ambient-temperature heat release of the blended binder and bound water of the blended supplementary cementitious materials.