KAJIAN SIFAT MEKANIK BETON RINGAN DENGAN PENGGUNAAN POLYSTYRENE SEBAGAI BAHAN SUBSTITUSI AGREGAT HALUS

Abstract

ABSTRACT
Lightweight concrete offers some advantages in reinforced concrete
construction. It can be produced by replacing the normal aggregate (sand and
gravel) with lightweight aggregate, either partially or fully, depending upon the
requirements of density and strength. The present study covers the use of
expanded polystyrene as fine lightweight aggregate in order to produce structural
lightweight aggregate.
These mixes were designed by using several variances of polystyrene
volume percentage by total fine aggregate. The substitution was done with 0%,
25%, 500/0, 750/0 and 1000/0 by total volume of fine aggregate, with 0,50 water
cement ratio. The Properties of hardened concrete namely compressive strength,
splitting tensile strength and flexural strength were tested in 28 days of curing
period.
It is observed that polystyrene lightweight concrete has sufficient strength
to be accepted as structural lightweight concrete in 25~'O substitution by total
volume of fine aggregate, with 17,35 MPa of compressive strength, but the
compressive strength will always decrease depending on the increasing of
polystyrene percentage. The splitting tensile strength of polystyrene lightweight
aggregate approximately 14%--18% of its compressive strength,for the normal
concrete it is nearly 10% of 28 days compressive strength. The flexural strength
was ranging between 20%-30% of its compressive strength, higher than normal
concrete that nearly 15% of its compressive strength.
Keywords: lightweight concrete, mechanical properties, polystyrene