Water permeability and carbonation on foamed concrete
Foamed concrete is a controlled density low strength material with density ranging from 300 kg/m3 to 1800 kg/m3 suitable for construction of walls. The acceptance of foamed concrete blocks and panels by the Construction Industry Development Board of Malaysia as components of industrialized buil...
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| Format: | Thesis |
| Language: | English English English |
| Published: |
2011
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| Subjects: | |
| Online Access: | http://eprints.uthm.edu.my/2865/1/24p%20SULAIMAN%20SUHAIZAD.pdf http://eprints.uthm.edu.my/2865/2/SULAIMAN%20SUHAIZAD%20COPYRIGHT%20DECLARATION.pdf http://eprints.uthm.edu.my/2865/3/SULAIMAN%20SUHAIZAD%20WATERMARK.pdf |
| Summary: | Foamed concrete is a controlled density low strength material with density
ranging from 300 kg/m3 to 1800 kg/m3 suitable for construction of walls. The
acceptance of foamed concrete blocks and panels by the Construction Industry
Development Board of Malaysia as components of industrialized building system
has promoted its commercial applications. It is made of cement, fine sand, water and
preformed foam. Its self-compacting properties have enhanced productivity for mass
production. Previous studies revealed findings on the use of large volume partial
cement replacement materials without adverse effect on its physical and mechanical
properties. This study focused mainly on the effect of the density of foamed concrete
on carbonation and water permeability. The ability to vary the density of foamed
concrete is considered a unique characteristic compared with normal concrete.
Carbonation is usually considered as a negative impact on reinforced concrete. It is
the process of pH reduction of concrete from 12.6 to 9.0 in the presence of carbon
dioxide and moisture. The reduction of alkalinity means the loss of protection
against corrosion to steel bars embedded within concrete. However, for non�structural applications of foamed concrete in wall construction without steel bars or
with the use of corrosion inhibitor, carbonation is turned into an advantage for
sustainable construction. The ability of foamed concrete to speed up the absorption
of carbon dioxide is an important aspect to be explored for its potential use in
reducing carbon footprint from the construction industry. The objective of this study
is to explore a relationship between carbonation depth, water permeability and the
density of foamed concrete. The laboratory tests were conducted on concrete cubes
and prisms for up to one and a half years. The water permeability method was
developed based on ISO/DIS 7031. The test results indicate that increasing density
of foamed concrete tends to reduce its water permeability and carbonation depth.
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The plot of carbonation depth against permeability coefficient produces a linear
relationship. The rate of carbonation was found to be inversely proportional to the
square root of density. An empirical formula incorporating density as a variable
based Currie’s formula is produced. This finding is expected to excite researchers
who are concerned with the use of concrete for sustainable construction. Its tendency
to absorb carbon dioxide faster than normal concrete from the atmosphere in the
carbonation process is expected to lead to widespread use of foamed concrete for
environmental and economical advantages |
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