The Importance of Standardization of Aggregate in Ethiopian Construction Industry
No Thumbnail Available
Date
2014-02
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Concrete is one of the versatile and widely used building materials in the world
Construction industry. Fine and coarse aggregates make about 70% by volume of
concrete production. It goes without saying that the quality of concrete is thus strongly
influenced by aggregate’s physical and mechanical properties as well as chemical
composition of the parent aggregate making material. Since most of these materials are
from natural sources in Ethiopian case like from rivers and from natural quarry site, their
quality and composition vary from time to time. Each truck of sand from the same place
at different time may not be the same and it is difficult to design mix proportion for each
truck of sand and this call for a standardization of materials in Ethiopia.
In my research I made concrete C-25, C-30 and C-40 as control mix by standardizing the
aggregate to the Ethiopian standard and other recommendation. By using the property of
this standardized aggregate mix design was made for control mixes, keeping the mix
proportion constant, aggregates from different sources were used to make concrete of the
same classes as control mix.
Compressive strength test were made at 3rd, 7th and 28th days for control mixes and for
mixes with nonstandard aggregates. Target mean strengths were achieved for control
mix by using Derba Cement 260kg/m3, 280kg/m3 and 380kg/m3 for C-25, C-30 and C-40
respectively. On the other hand concrete with non standard aggregate didn’t achieve
target mean strength rather up to 48% reduction in strength was observed.
Description
Keywords
Construction industry