Abstract:
This experimental study carried out to investigate the quality and suitability of using locally
available coarse aggregates in Jimma Town to make a concrete mix. Aggregate samples
were collected from five different quarries according to ASTM sampling procedure. The
experiments were performed on collected samples of coarse aggregates to evaluate their
physical and mechanical properties as per ASTM and BS standards. Concrete compositions
made, using the same aggregates were tested for mechanical properties (Engineering
property and compressive strength). Concrete mixtures were prepared, tested and
compared regarding Compressive strength and Engineering property. These tests were
carried out to evaluate the strength properties at 7
th day, 14th day and 28th day. The results
of this study showed that the concrete made using Geruke quarry crushed coarse aggregate
performed satisfactorily regarding mechanical properties. Moreover, their performance
was found to be quite similar to those aggregates commonly available and used in the town
of Jimma quarry sites such as Beda Buna, Sheteradion, Kisho, and Buna Board quarry
crushed coarse aggregates. The result showed that sheteradion, kisho, and geruke crushed
coarse aggregate, were within the acceptable limit of ASTM C-33 standards. Whereas beda
buna and buna board crushed coarse aggregates showed insignificant amount (89.1% and
87.49% percent pass through sieve no 25.0mm) or below the standards. The other
aggregate quality test for Bulk density, Surface water contents, Specific Gravity,
Absorption, Aggregate Impact Value, Aggregate Crushing Value, Abrasion and Impact in
the Los Angeles and soundness by Sodium, were noted within the stipulated standard and
limits. Properties of the concrete, mostly depend on the characteristics of the aggregates.
It was observed that except SCCA and KCCA aggregates, the rest of the aggregates
revealed higher compressive strength which is satisfactorily. Therefore, it can be
concluded that the strength and durability of concrete are greatly influenced by the quality,
strength, and durability of the coarse aggregate used. The result substantiated that
variation in the compressive strength of concrete mixes with BBCCA, SCCA, KCCA,
BB'CCA, and GCCA, with the values of 33.8 Mpa, 29.6 Mpa, 28.3 Mpa,32.7 Mpa and 34.7
Mpa respectively.
