Early-Stage Microstructures of Cemented Paste Backfill with Different Binders

Abstract

The early-stage (within 7 days of hydration) microstructures of cemented paste backfill (CPB) with different binders were compared using SEM and EDXS. The two types of CPB, denoted CPB1 (mixed with 5% Portland cement, PC) and CPB2 (mixed with 5% complex binder, CB), were prepared. In CPB, white particle accumulations (WPA) smaller than 10 μm filled the spaces surrounding the big tailings, small amounts of the WPA also adhering to the surfaces of the big tailings. The PC products self-aggregated within the CPB1 paste, and the CB hydration products were relatively evenly dispersed throughout the CPB2 paste. The initial microstructure of the CPB2 was more compact than that of the CPB1.