.

In this study, effect of coarse aggregate type on the modulus of eladticity of concrete was investigated.Three different
coarse aggregate samples were used namely: granite, sandstone and unwashed gravel. Amongst other tests carried
out, the two principal tests performed include compressive strength test and modulus of elasticity test.The different
coarse aggregates were used to make 18 concrete specimens each. Granite based concrete specimens gave a mean
modulus of elasticity of 57.3 N/mm2, 84.9 N/mm2, and 86.6 N/mm2 on the 7th, 14th and 28th day of testing. Sandstone
based concrete specimens gave a mean modulus of elasticity of 44.0 N/mm2, 68.3 N/mm2and 77.3 N/mm2on the 7th,
14th and 28th day of testing. Gravel based concrete specimens gave a mean modulus of elasticity of 38.5 N/mm2,
48.2N/mm2and 70.1 N/mm2on the 7th, 14th and 28th day of testing. From the results, granite based concrete gave the
highest mean modulus of elasticity followed by that of sandstone, then that of gravel was the least. And this indicates
that the granite based concrete gave the highest compressive strength than the others thus making it the most
preferred coarse material amongst them.