Relationships between Compressive Strength and Microstructure in Mortars with Iron Ore Tailings as Fine Aggregate

In this study, the effect of Iron Ore Tailings (IOT), as fine aggregate in mortars, on microstructure and compressive strength with 14 days was observed on mortar specimens. The replacement ratios for IOT as fine aggregate were 60% and 100%. Pore structure parameters were measured with the instrument of MIP and calculated with corollary software. Situations of interface between aggregates and hard cement pastes were observed by FEI quanta 200 SEM. Consequently, it was seen that IOT can improve mortar’s compressive strength because of tighter interface between aggregate and hard cement paste and enhanced porous structure related to the finer structure of IOT comparing to reference sand.