Influence of PT Vale’s Granulated Gradation Nickel Slag Aggregate on Compressive Strength of Concrete

Abstract

Influence of granulated gradation nickel slag aggregate on compressive strength of concrete has been investigated. In this study, the influence of granulated gradation nickel slag aggregate with aggregate size LS 9.50 mm, LS 5.60 mm, LS 2.36 mm, LS 2.00 mm and the combination of those fourth aggregate size on compressive strength and microstructure of concrete has reported. The concrete was prepared according to SNI 03-1972-1990. Samples then characterized using universal testing machine controller respect to ASTM C39M-01 method to obtain the compressive strength value and scanning electron microscope to obtain morphology of all samples. Results show that sample with nickel slag aggregate size at 5.60 mm has highest compressive strength value at (44.05 ± 1.93) MPa. Characterization of microstructure shows a good interface between aggregate and cement paste. The morphology after compressive testing shows that cracks were occurred in the cement paste, not between aggregate and paste interface. It can be concluded that the aggregate size of nickel slag was directly proportional to the compressive strength of the concrete depending on the bond between cement paste and the size of nickel slag aggregate.