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Interlocking compressed earth blocks (ICEB) are soil stabilized based blocks that allows for mortarless construction. Various studies have been conducted to improve the durability of bricks by using environmental friendly solution. This is because common method used by the construction industries generally involving the use of chemical based substances which will promote pollution to the surrounding. This paper provide the results of Ureolytic Bacteria (UB) in improving the compressive strength and water absorption properties with the percentage of 1%, 3% and 5% UB for 7th ,14th and 28th days of testing. The bacteria were added as partial replacement of limestone water in ICEB. The results of compressive strength and water absorption show that the increment of 15.25% strength and reduction of 15.66% water absorption with 5% of UB on the 28th days of testing compared to the control specimen. Therefore it is hoped that the positive results on using bacteria will continue to improve the durability of the ICEB as one of the environmental friendly solution in order to achieve sustainable construction.

The objective of this study is to isolate sulphate reduction bacteria (SRB) from acid mire water collected at Sg Pelepah Kota Tinggi, Johor Malaysia. The isolation process was conducted in high alkaline and anaerobic conditions to sustain the bacteria in concrete environment. Properties tests such as compressive strength and water penetration were conducted. The result showed that optimal growth condition of sulphate reduction bacteria is pH 9-10. It was also observed that the bacteria is a coccus shape after gram staining process. The bacteria was used after 10 days of culturing prior to growth curve measurement. The liquid culture containing sulphate reduction bacteria were used at 1%, 3% and 5% as replacement ratio of water content. Concrete specimens were cured in the air conditions for 7, 14 and 28 days. Maximum increment on compressive strength was 13.0% and decrement in water penetration was 8.5% occurred with 5% of SRB. The enhancement in compressive strength and water penetration performance was due to calcium precipitation within concrete pores. Image of scanning electronic microscopy (SEM) showed bacteria sustained and survived in concrete environment by reducing diameter of pores in concrete specimens.

Interlocking Compressed Earth Block (ICEB) are cement stabilized soil blocks that allow for dry stacked construction. Because of this characteristic, the process of building walls is faster and requires less skilled labour as the blocks are laid dry and lock into place. However there are plenty room for improving the interlocking blocks by increase its durability. Durability of bricks are affected by several factors and one of them are water absorption. High water absorption level will results in low durability. Many studies have been conducted in order to improve the durability of bricks by using environmentally method. One of the method is by inducing bacteria into bricks. Bacteria in brick induced calcite precipitation (calcite crystals) to cover the cracks continuously. Therefore, the issues of durability of bricks can be fully solved. This paper offer a review on interlocking compressed earth blocks and the use of bacteria in reducing water absorption level.

Polyethylene terephthalate (PET) bottles are plastic containers that are typically discarded, and thus, cause environmental pollution. To solve this problem, PET bottles are recycled incorporating with concrete. A ring-shaped PET (RPET) fiber are introduced in this study and designed with a special shape to mobilize fiber yielding rather than fiber pullout. Therefore, aim of this paper is to investigate the influence of RPET bottles fibre in terms of toughness strength. The width of RPET fibers is fixed at 5 and 10 mm and the loads were applied to the third points of the specimen. The experiment indicates that RPET-5 and RPET-10 FC presented an increase in the toughness index of I20 on averages of 23.1% and 39.9% respectively, compared to normal specimens. It can conclude that incorporating RPET fiber in concrete presents significant improved of concrete properties.

This paper presents the species of bacteria used in this study as well as the effect of the bacteria on compressive strength of bioconcrete. Bioconcrete is not only more environmentally friendly but it is easy to procure. The objective of this research is to identify the ureolytic bacteria and sulphate reduction bacteria that have been isolated and further use the bacteria in concrete to determine the effect of bacteria on compressive strength. Identification of bacteria is conducted through Polymerase chain reaction (PCR) method and DNA sequencing. The DNA of the bacteria was run through BLAST algorithm to determine the bacterial species.The bacteria were added into the concrete mix as a partial replacement of water. 3% of water is replaced by ureolytic bacteria and 5% of water is replaced by sulphate reduction bacteria. After running BLAST algorithm the bacteria were identified as Enterococcus faecalis (ureolytic bacteria) and Bacillus sp (sulphate reduction bacteria). The result of the compressive strength for control is 36.0 Mpa. Partial replacement of 3% water by ureolytic bacteria has strength of 38.2Mpa while partial replacement of 5% of water by sulphate reduction bacteria has strength of 42.5Mpa. The significant increase of compressive strength with the addition of bacteria shows that bacteria play a significant role in the improvement of compressive strength.