Experimental study on the reactivity of aggregate in concrete

The specimens mixed with cement and various crushed minerals (149–74 μm) were cured at 80°C in saturated steam for 28–180 days as the basic study for cement-aggregate reactions. Quartz and feldspars (microcline, albite and anorthite) reacted with the cement paste, whereas hornblende, augite and olivine did not react. Anorthite was the most reactive and the reactivity of quartz, microcline and albite were almost the same as each other. Jennite was formed by cement-quartz reaction and 11 Å tobermorite, CSH (II) and hydrogarnet were formed by cement-anorthite reaction. The compressive strength of the specimens in which aggregates reacted to cement paste increased as the curing time was prolonged.