| Summary: | Oil palm shell (OPS) is the hard endocarp which surrounds the palm kernel
and received as crushed pieces during the extraction of palm oil. It is an agricultural
waste and can be found in abundance in Malaysia. Economic and environmental
benefits as well as decreasing the use of natural resources can be achieved if OPS can
be utilised as a building material. Promising results showed that OPS has good
potential to be used as coarse aggregate replacement in making structural lightweight
concrete. It has also been previously established that polyvinyl alcohol (PVA) can be
used to improve the properties of OPS concrete. Chloride induced reinforcement
corrosion is an important area of study which needs to be investigated, especially for
concrete structures exposed to marine environments. Therefore, this paper presents an
experimental study on the chloride penetrability of PVA treated OPS concrete in
comparison to that of raw OPS concrete using the 90-day salt ponding test. The
effects of different curing conditions (full water curing, air-dry curing and site curing)
on the chloride penetration resistance of PVA treated OPS concrete and raw OPS
concrete were also studied. Both PVA treated OPS and raw OPS concrete surface
were ponded with 3% sodium chloride solution up to 90 days, and the chloride
profiles were measured by analysing concrete dust samples extracted from different
depth intervals from the chloride exposed concrete surface. Subsequently, chloride
diffusion coefficients were determined by fitting the experimental data to Fick’s
second law of diffusion. From the test results, it was found that PVA treated OPS
concrete had high surface chloride concentration as compared to raw OPS concrete.
However, PVA treated OPS concrete showed higher resistance to chloride penetration
as compared to raw OPS concrete as indicated from the chloride diffusion coefficient.
The results indicated that curing conditions also have a significant influence on the
chloride resistance of PVA treated OPS concrete and raw OPS concrete.
|
|---|