The rise in the prices of raw material leads to the search for cheaper and lighter a raw material
which reflects on the total cost of the construction project .The aim of this study was to reduce the
bulk weight of concrete through partial replacement of the coarse aggregates with variable
percentages of light weight aggregates (Pumice). In addition to that further investigation on
reducing the bulk weight through development of hollow core in concrete cubes with variable
diameters. Silica fume was added to concrete mix in order to enhance the performance of the
concrete mix. Use of silica fume with 450Kg/m3
cement achieved positive results in this study
even with the existence of a Hollow core in concrete.