Study of petrography and physicomechanical characteristic of Batu Angus Lava, Mount Gamalama, Ternate Island, Indonesia : Implication for its uses as construction material

One of the sources of building materials in the Ternate area is Batu Angus. In the present study, the determination of the usage quality of Batu Angus as a construction material in accordance with the standards was carried out through several tests. The analysis carried out in this research was in the form of petrographic analysis as well as physical property and mechanical property analysis. Based on the physical properties testing, the effective density of Batu Angus was 2.53-2.81 gr/cm3 and the absorption value was 1.42-2.00 %. Based on the analysis of its mechanical properties, the compressive strength of Batu Angus was 533.74-574.65 kg/cm2 and wear resistance was 28.64-52.11%. The main mineral compositions of Batu Angus include plagioclase, pyroxene and groundmass. The rock encompassed micro porphyry aphanitic, inequigranular, hyalopilitic, and vesicular textures. Based on the engineering value, texture and mineralogical characteristics, Batu Angus can be used as per the SNI 03-0394-1989 standard as light building materials foundation, curbstone, pavements, as well as decorative stone in construction activities.