EFFECT OF MICROBIAL INDUCED CALCIUM CARBONATE PRECIPITATION ON THE PHYSICAL AND MECHANICAL PROPERTIES OF CONCRETE
In enhancing the quality of tunnel support, it usually needs a better quality of concrete. However, it requires high cost and generates a negative impact on the environment. Therefore, it is necessary to use an alternative method for enhancing the quality of the concrete. Some researchers had exa...
Saved in:
| Main Author: | |
|---|---|
| Format: | Theses |
| Language: | Indonesia |
| Online Access: | https://digilib.itb.ac.id/gdl/view/40045 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | In enhancing the quality of tunnel support, it usually needs a better quality of concrete.
However, it requires high cost and generates a negative impact on the environment.
Therefore, it is necessary to use an alternative method for enhancing the quality of the
concrete. Some researchers had examined the innovation method well-known as
biocementation which utilizes the calcium carbonate precipitation bacteria for
improving the quality of the concrete. Therefore, the main aim of this study is to
investigate the influence of MICCP bacteria on the physical and mechanical properties
of concrete that is beneficial for tunnel support.
In this study, the selection of bacteria and media in which suitable for the formation of
calcium carbonate was first conducted by evaluating the growth curve, pH, and Eh.
Three selected bacterial species, VA 1, VA 3, and VA 5 were used in examining the
physical and mechanical properties of concrete samples. The most optimum bacteria,
VA 1, was selected subsequently for physical and mechanical properties testing,
inoculum concentration, as well as the addition of calcium lactate pentahydrate. Selfhealing phenomenon on artificial crack was observed using a binocular microscopy,
while analysis using X-ray diffraction (XRD) and scanning electron microscopy-energy
dispersive x-ray spectroscopy (SEM-EDS) were carried out to justify the formation of
calcium carbonate. The results suggested that the utilization of mixture between 10%
of strain VA 1 with the addition of calcium lactate pentahydrate of 0.5% w/w cement
into the mix design provides the most optimum properties of concrete samples by an
increase in compressive strength, indirect tensile strength (Brazillian test), and flexural
strength of 45%, 36%, and 17% higher than the control sample, respectively. In
addition, the most significant value of porosity and moisture content has been
decreased by 9% and 13%, respectively, from the control sample. Consequently,
bacteria VA 1 is highly potential to be applied in field scale with further optimization. |
|---|