Optimum concentration of Bacillus megaterium for strengthening structural concrete

Andalib, Ramin; Majid, Muhd Zaimi Abd; Hussin, Mohd Warid; Ponraj, Mohanadoss; Keyvanfar, Ali; Mirza, Jahangir; Lee, Han Seung

doi:10.1016/j.conbuildmat.2016.04.142

Cited by 175 publications

(86 citation statements)

References 16 publications

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“…Concerning bacterial mortar specimens without calcium lactate (BB specimen), the declined mortar strength might be caused by the deficient precipitation of calcium carbonate inside the mortar matrix under bacterial metabolisms at 20% v/v of bacterial inoculum in spite of the most precipitation for self-healing on the artificial www.nature.com/scientificreports/ crack for 28 days. This phenomenon might occur due to the different optimum bacterial concentrations, as reported by the previous studies 34,35 . In comparison, the bacterial mortar specimens with calcium lactate (BL specimen) exhibited the highest increase in mortar strength (Fig.…”

Section: Discussionmentioning

confidence: 68%

Bacteria incorporated with calcium lactate pentahydrate to improve the mortar properties and self-healing occurrence

Chaerun

Syarif

Wattimena

2020

Sci Rep

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Concrete can be harmful to the environment due to its high energy consumption and CO2 emission and also has a potential crack formation, which can promote a drop in its strength. Therefore, concrete is considered as a non-sustainable material. The mechanisms by which bacterial oxidation of organic carbon can precipitate calcite that may fill the voids and cracks on cement-based materials have been extensively investigated to prevent and heal the micro-cracks formation. Hence, this study focused on utilizing a new alkaliphilic bacterial strain indigenous to an Indonesian site, Lysinibacillus sphaericus strain SKC/VA-1, incorporated with calcium lactate pentahydrate, as a low-cost calcium source, with various bacterial inoculum concentrations. The bacterium was employed in this study due to its ability to adapt to basic pH, thus improving the physical properties and rejuvenating the micro-cracks. Experimentally, the addition of calcium lactate pentahydrate slightly affected the mortar properties. Likewise, bacteria-incorporated mortar exhibited an enhancement in the physical properties of mortar. The highest improvement of mechanical properties (an increase of 45% and 36% for compressive and indirect tensile strength, respectively) was achieved by the addition of calcium lactate pentahydrate incorporated with 10% v/v bacterial inoculum [about 7 × 107 CFU/ml (colony-forming unit/ml)]. The self-healing took place more rapidly on bacterial mortar supplemented with calcium lactate pentahydrate than on the control specimen. XRD analysis demonstrated that the mineralogical composition of self-healing precipitates was primarily dominated by calcite (CaCO3), indicating the capacity of L. sphaericus strain SKC/VA-1 to precipitate calcite through organic carbon oxidation for self-healing the artificial crack on the mortar. To our knowledge, this is the first report on the potential utilization of the bacterium L. sphaericus incorporated with calcium lactate pentahydrate to increase the mortar properties, including its self-healing ability. However, further study with the water-cement ratio variation is required to investigate the possibility of using L. sphaericus and calcium lactate pentahydrate as an alternative method rather than reducing the water-cement ratio to enhance the mortar properties.

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Section: Discussionmentioning

confidence: 68%

Bacteria incorporated with calcium lactate pentahydrate to improve the mortar properties and self-healing occurrence

Chaerun

Syarif

Wattimena

2020

Sci Rep

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“…The optimum compressive strength was reported 10 5 cells/ml, whereas the matrix integrity disrupts due to excessive bacterial activity at 10 7 cells/ml 18,28 . In another research 29 , the compressive strength of bacterial concrete was reported to be increased in 10 3 -10 5 (cfu/ml), whereas the strength was found to be decreased in/ after 10 7 (cfu/ml), compared to the concrete sample without bacteria. In the present study, 10-10 3 (cfu/ml) of bacteria are survived after mixing with cement, which produced the urease enzyme.…”

Section: Resultsmentioning

confidence: 92%

Efficient option of industrial wastewater resources in cement mortar application with river-sand by microbial induced calcium carbonate precipitation

Huang

Chen

Maity

et al. 2020

Sci Rep

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The industrial wastewater disposal has been growing attention for environmental protection and resource substitution, current decades. Similarly, the durability enhancement of concrete has increased attention by microbial induced CaCO 3 precipitation (MICP) process (biocalcification). However, ecofriendly utilization of industrial wastewater in concrete formation is unstudied so far. The present study was carried out to evaluate the effect of industrial wastewater on the formation of cement mortar, compressive strength and water absorption. The biocement mortar strength (y) increased (y = 0.5295× 2 + 1.6019×+251.05; R 2 = 0.9825) with increasing percentage of organic wastewater (x) (BM 0 -BM 100 ) by MICP, where highest strength (280.75 kgf/cm 2 ) was observed on BM 100 (100% wastewater), compared to control (252.05 kgf/cm 2 ). The water absorption (y) of biocement mortar decreases (y = −0.0251× 2 -0.103× + 15.965; R 2 = 0.9594) with increment of wastewater (x) (%) (BM 0 -BM 100 ), where a minimum-water-absorption (14.42%) observed on BM 100 , compared to control (15.89%). SEM micrograph and XRD shows the formation of most-distinctive CaCO 3 crystallization (aragonite/calcite) (acicular, brick shape, massive and stacked structure) inside biocement mortar (BM 100 ), which fills the pores within cement mortar to form a denser structure, by microbial organic wastewater. Thus, present findings implied a cost-effective of MICP technology to improve the concrete properties along with the mitigation of industrial wastewater pollution, which goes some way towards solving the problem of industrial wastewater pollution.Since the industrial revolution in 18 th century, the quality of life of human has improved drastically and the population grows exponentially, worldwide. As a result, the demand for sturdy and comfortable houses has been on the rise. The cement, a most common building material that use for constriction, worldwide. However, manufacturing cement produces a large amount of carbon dioxide that harms the environment 1,2 . Therefore, the researchers in civil engineering sector have been investigating to extend the service life of cement in building constriction 3-6 . On the other hand, the researcher reported that the bioremediation process is able to strengthen the structural integrity of buildings and reduces water absorption. Furthermore, the researchers have been trying to report, how organisms repair themselves, and they have been trying to develop ecofriendly bioremediation systems 7-9 . However, the bioremediation along with repair system has not been reported clearly, so far.The percentage of water adsorption was calculated as follow as. Water absorption (%) = (C-A)/(C-D) × 100; where A is the weight (g) of the oven dried sample in air; C is the weight (g) of sample after immersion and boiling; and D is the apparent weight (g) of sample in water after immersion and boiling.Characterization of synthesized material. The crystallinity of MICP synthesized powders and biocement mortar cube was analyzed by XRD ...

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“…Andalib, et al, [11] examined Bacillus megaterium of five different cell concentrations (1×10 6 to 5×10 6 cfu/ml) were directly added into the fresh concrete mixture to achieve optimal bacterial concentration. The substantial increase in strength was observed at different ages for 3×10 6 cfu/ml.…”

Section: Ca (C4h6o4) + 4o2mentioning

confidence: 99%

Experimental characterisation of non-encapsulated bio-based concrete with self-healing capacity

Mohammed

Ortoneda-Pedrola

Nakouti

et al. 2020

Construction and Building Materials

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The main reason for early corrosion in Reinforced Concrete (RC) structures is crack formation within the concrete cover. Cracks can lead to leakage problems, allowing chloride, oxygen, water and other aggressive chemicals to enter into concrete and eventually causes corrosion of steel reinforcement. The paper shows some results of a novel bio concrete with biological self-healing agent, which added into the concrete mixture, autonomously and actively, inhibits the concrete cracks and potential premature reinforcement corrosion. Two compositions of concrete samples were prepared and casted -CEMI and CEMIII with 60% of Ground Granulated Blast Furnace Slag (GGBS) with and without non-encapsulated bio-product utilising iron respiring bacteria. The developed bio-mineral is capable of sealing cracks and blocking pores resulting in a delay of waterborn ions in RC structures, acting as a diffusion barrier of oxygen to protect steel reinforcement's passivity towards corrosion. The fresh test results show that these concretes have the potential to be used in RC heavily reinforced and manually compacted sections with vibrations. The water absorption velocity has been significantly reduced with the inclusion of bio-agent in CEMI and CEMIII concretes samples, which was associated with pores sealing. Maximum water absorption via capillary tends to reduce at least 25% when bio-agent was introduced to concrete type CEMIII. Other results emphases the efficiency of the bio-product in CEMIII medium. The bio-agent does not decrease the compressive strength of tested concretes either for CEMI and CEM III. SEM observation shows that the crystals were well developed near the surface of the crack.

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Optimum concentration of Bacillus megaterium for strengthening structural concrete

Cited by 175 publications

References 16 publications

Bacteria incorporated with calcium lactate pentahydrate to improve the mortar properties and self-healing occurrence

Bacteria incorporated with calcium lactate pentahydrate to improve the mortar properties and self-healing occurrence

Efficient option of industrial wastewater resources in cement mortar application with river-sand by microbial induced calcium carbonate precipitation

Experimental characterisation of non-encapsulated bio-based concrete with self-healing capacity

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