Optimum rice husk ash content and bacterial concentration in self-compacting concrete

Ameri, Farshad; Shoaei, Parham; Bahrami, Nasrollah; Vaezi, Mohammadsadegh; Ozbakkaloglu, Togay

doi:10.1016/j.conbuildmat.2019.06.190

Cited by 99 publications

(42 citation statements)

References 62 publications

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“…14(a)]. The shape of these CaCO 3 crystals, formed inside the cracks, was similar to the finding of the study using Sporosarcina pasteurrii bacteria (Ameri et al 2019). Rod-shaped crystals [ Fig.…”

Section: Self-healing Repeatability and Strength Improvement Using Basupporting

confidence: 79%

A Study on Biomineralization using <i>Bacillus Subtilis</i> Natto for Repeatability of Self-Healing Concrete and Strength Improvement

Huynh

Imamoto

Kiyohara

2019

ACT

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Recent studies in the field of concrete materials show that the early cracking criteria in micro-size can occur as soon as the cement matrix becomes hardened. In many ways, these cracks can become macro-size and opened cracks resulting in significant issues for the durability and appearance of concrete structures as water leakage and corrosion. The technique of self-healing using bacteria has recently received attention for its potential applications. However, the effectiveness and the repeatability of this method over a long period have not been clarified. The information on both the survival and the number of bacteria after healing is limited. This paper aims to improve the self-healing ability and repeatability of concrete when using Bacillus subtilis natto. The experimental studies evaluate the effect of biomineralization with lightweight aggregate as the protecting-carrying vehicle, which can control the release of healing fluid through four cracking-healing cycles. The urease activity and the biomineralization of the bacteria with urea as the main carbon source were assessed and the effect of cracking age on the self-healing capacity, associated with the compressive strength improvement was studied. The results obtained from the optical microscope and SEM/EDS analysis indicated the existence of bacteria CaCO 3 forming in concrete after four healing cycles. During long duration, bacterial concentration in concrete was determined by microscopic counting method. Based on experimental results, the restoration of the compressive strength confirmed the high self-healing ability of concrete when using bacteria in lightweight aggregate.

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Section: Self-healing Repeatability and Strength Improvement Using Basupporting

confidence: 79%

A Study on Biomineralization using <i>Bacillus Subtilis</i> Natto for Repeatability of Self-Healing Concrete and Strength Improvement

Huynh

Imamoto

Kiyohara

2019

ACT

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“…As expected, Figure 3(b) shows a massive amount of CaCO3 formed inside the cracks by the biomineralization of Bacillus subtilis natto after 28 days. According to SEM observation, the shape of CaCO3 crystals was similar to the finding of the study using Sporosarcina pasteurrii bacteria (Ameri et al, 2019). These rod-shaped crystals could be a reinforced component in cracks, similar to the strength improvement mechanism of cementitious composite through whisker CaCO3 (Cao et al, 2019).…”

Section: Compressive Strength Improvement Using Bacterial Lightweightsupporting

confidence: 82%

Compressive Strength Improvement and Water Permeability of Self-Healing Concrete Using Bacillus Subtilis Natto

Nguyen¹,

Imamoto²,

Kiyohara³

2020

XV International Conference on Durability of Building Materials and Components. eBook of Proceedings

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In recent years, many projects have been carried out to enhance the durability of concrete structure from the influence of cracks. Generally, managing cracks should be a rather preventative method for sustainable development. Based on that, Bacillus subtilis natto-a local bacterium in Japan was found to have the ability to form CaCO 3 , which can be used as healing materials for cracks in the concrete structure. The bacterial biomineralization immobilized in lightweight aggregate was studied to improve the compressive strength by healing the cracks and densifying the structure. Moreover, as an essential parameter for durability enhancement, the water permeability of self-healing concrete through a water-flow system was carried out. Experimental results on the behavior of the materials indicate that Bacillus subtilis natto could lead the compressive strength to 40 % higher than the controls. Promising result in preventing the water through the cracks confirmed the self-healing effect with more potential in larger-scale.

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“…Calcium carbonate produced based on the aforementioned reactions could fill the pore and compact the cement-based materials, resulting in strength enhancement 31 , 34 , 39 . This product could be a useful filling material that can bind tiny aggregates within the mortar matrix.…”

Section: Discussionmentioning

confidence: 99%

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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Optimum rice husk ash content and bacterial concentration in self-compacting concrete

Cited by 99 publications

References 62 publications

A Study on Biomineralization using <i>Bacillus Subtilis</i> Natto for Repeatability of Self-Healing Concrete and Strength Improvement

A Study on Biomineralization using <i>Bacillus Subtilis</i> Natto for Repeatability of Self-Healing Concrete and Strength Improvement

Compressive Strength Improvement and Water Permeability of Self-Healing Concrete Using Bacillus Subtilis Natto

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

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