Concrete is a mixture of portland cement, fine aggregate, and water with or
without additives that form a solid mass. Along with increasing age, the concrete
will harden and reach the design strength (fc’) at the age of 28 days. The faster the
development of an area, the more material needs are used. This causes more places
to take the material, such as sand. In this study, the compressive strength of
concrete was analyzed using Bunton Adipala Beach sand as fine aggregate.
The purpose of the study was to determine the value of the compressive
strength of concrete using sand from Bunton Adipala Beach with washed and
unwashed sand treatment. The test object used is a cylinder with a diameter of 15
cm and a height of 30 cm. The concrete samples in each variation. Concrete
samples were tested at the age of 7 days and then converted at the age of 28 days.
The results of this study are the average compressive strength of concrete
at 7 days of age with a variation of washed sand of 11,6216 Mpa while the variation
of unwashed sand is 11,1698 Mpa. And the average compressive strength of 28 day
old converted concrete with variations of washed beach sand is 17,879 Mpa and
17,184 Mpa of unwashed beach sand. So from the results of this study the value of
the compressive strength of concrete did not meet the planned, namely 18,68 Mpa.