Study of bottom ash from Malaysia municipal solid waste incineration as binder material In cement
Abstract
The garbage problem in Malaysia is a serious concern. The vacant land area to
be used as a landfill is also limited. This has led the government to apply the incinerator
system as a method to reduce the quantity of solid waste dramatically. This system
produces two types of waste which is fly ash and bottom ash. In essence, fly ash has
been used as an additive substance in cement since it has a few pozzolonic and
cementatious properties. While bottom ash, has been used as a replacement material for
aggregates in road construction. Some important laboratory testing such as XRF
Analysis, Sieve Analysis and AAS (Atomic Absorption Spectrophotometry) has been
implemented. At the beginning stage, the sample being oven-dried for about 24 hours
and then sieve to get the particle size of less than 100μm. It can be classified as sand to
silt-clay with high percentage of coarse to medium sand. More than 5% out of every 500
gram are going through the sieve tray with the particle size of less than 100μm. The
particles sizes are comply with the required size for cement material. Sieve sample then
will be forwarded to the XRF test to determine the chemical composition in the samples.
The chemical compositions in the bottom ash are most likely similar to the cement itself
and it also has the cementatious and pozzolonic properties. Research sample of bottom
ash has been classified as Class C according to the requirement needed in ASTM
C618:2013 (edited version). It is determined by the sum of SiO2 + Al2O3 + Fe2O3.
Therefore, as a conclusion, bottom ash could be a binder material in cement but
somehow need an extra testing to ensure the advantages and the suitability of the sample
as binder material.