THE EFFECT OF CLAYEY IMPURITIES IN SAND ON THE CRUSHING
STRENGTH OF CONCRETE (A CASE STUDY OF SAND IN AKURE
METROPOLIS, ONDO STATE, NIGERIA)
30th Our World in Concrete and Structures (OWICs) - 2005
L M Olanitori, Federal University of Technology, Akure, Nigeria
A O Olotuah*, Federal University of Technology, Akure, Nigeria.
Clay, Concrete, Impurities, Sand
This paper assesses the effect of clayey impurities in the sand available in Akure metropolis
of Ondo State, Nigeria. Ten samples of sand were collected from ten different locations in
the city. The field settling method was used to determine the percentage content of clay in
each sand samples.
From each san sample, 15 concrete cubes were casted. Steel cubes of 150 x 150 x 150cm3
and 1:2:4 mix ratio were used in the casting. Curing of the concrete cubes was done by
immersion in water. Portland cement was used. The cubes were crushed out 28 days. It
was discovered that the higher the percentage content of clay in the sand samples, the
higher the reduction effect on the cube strength. Depending on the percentage content of
clay the reduction in strength could be as high as 70% based on 20N/mm2 cube strength at
28 days. This paper proffers recommendations on means of achieving required cube
strength when using sand from the study area (Akure, Nigeria).