Remediation of Concrete Using Microorganisms

Ramachandran, Santhosh K.; Ramakrishnan, V.; Bang, S.

doi:10.14359/10154

Cited by 143 publications

(53 citation statements)

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“…In addition, different metabolic pathways are employed by the bacteria for the precipitation of CaCO3 depending on the species and the environmental conditions . The biogenic self-healing agents, which are frequently encountered in the literature, follow three different metabolic routes; i.e., the enzymatic hydrolysis of urea (Ramachandran et al, 2001;De Muynck et al, 2008;Wang et al, 2014), the oxidation of organic carbon (Jonkers et al, 2010;Wiktor and Jonkers, 2011;Jonkers and Mors, 2012;Stuckrath et al, 2014;Xu and Yao, 2014;Sierra Beltran et al, 2015;Paine et al, 2016;Tziviloglou et al, 2016), and the anoxic oxidation of organic carbon (Ersan, 2016). This paper discusses the oxidation of organic carbon system.…”

Section: Introductionmentioning

confidence: 99%

Selection of Nutrient Used in Biogenic Healing Agent for Cementitious Materials

et al. 2017

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Biogenic self-healing cementitious materials target on the closure of micro-cracks with precipitated inorganic minerals originating from bacterial metabolic activity. Dormant bacterial spores and organic mineral compounds often constitute a biogenic healing agent. The current paper focuses on the investigation of the most appropriate organic carbon source to be used as component of a biogenic healing agent. It is of great importance to use an appropriate organic source, since it will first ensure an optimal bacterial performance in terms of metabolic activity, while it should, second, affect the least the properties of the cementitious matrix. The selection is made among three different organic compounds, namely calcium lactate (CaL), calcium acetate (CaA), and sodium gluconate (NaG). The methodology that was used for the research was based on continuous and non-continuous oxygen consumption measurements of washed bacterial cultures and on compressive strength tests on mortar cubes. The oxygen consumption investigation revealed a preference for CaL and CaA, but an indifferent behavior for NaG. The compressive strength on mortar cubes with different amounts of either CaL or CaA (up to 2.24% per cement weight) was not or it was positively affected when the compounds were dissolved in the mixing water. In fact, for CaL, the increase in compressive strength reached 8%, while for CaA, the maximum strength increase was 13.4%.

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Section: Introductionmentioning

confidence: 99%

Selection of Nutrient Used in Biogenic Healing Agent for Cementitious Materials

et al. 2017

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“…For this test, three samples were used: the control with 0.85% of saline solution, the bacteria grown in MH dissolved in 0.85% saline solution and the bacteria grown in ST dissolved in 0.85% saline solution. To calculate the concentration of bacteria in the medium through the absorbance, Equation 4 was applied [17]. …”

Section: Quantification Of Bacteriamentioning

confidence: 99%

“…After complete this stage, the culture medium that resulted in the highest cell growth was identified and then the procedure was repeated with this medium to obtain the required concentrations in the experiment, which are 0.3x10 and 1.2x10 8 spores/mL according to previous experiment with the bacteria B. pasteurii and Pseudomonas aeruginosa [17].…”

Section: Quantification Of Bacteriamentioning

confidence: 99%

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Crack filling in concrete by addition of Bacillus subtilis spores – Preliminary study

Schwantes-Cezario¹,

Peres²,

Fruet³

et al. 2018

DYNA

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This study aimed to analyze the performance of two concrete mixtures with the addition of B. subtilis spores regarding their capacity of filling cracks during the curing time, evaluating whether the addition can influence the compressive strength of the concrete. For so, six concrete mixtures were studied divided in two mix compositions: 1:1:2 and 1:2:3 (cement: sand: gravel) with w/c of 0.33 and 0.45, respectively. For each composition were added concentrations of 0, 0.3x10 8 or 1.2x10 8 of B. subtilis spores/mL. The results showed that all the samples with spores addition presented crystals precipitation, possibly calcium carbonate, that visually filled the cracks. However, more studies of microstructural analysis should be conducted to prove that the cracks were closed. The compressive strength presented satisfactory results, because the addition of 1.2x10 8 spores/mL did not present significant differences in compressive strength at probability level of 5%, when compared to the reference concrete.Keywords: bioconcrete; concrete with addition of spores; Bacillus subtilis; crack filling; cracks.Relleno de fisuras en concreto por la adición de esporas de Bacilos subtilis -Estudio preliminar ResumenEste estudio tiene como objetivo analizar el desempeño de dos composiciones de hormigón con adición de esporas de B. sutilis con relación a su capacidad de relleno de fisuras durante el periodo de cura, evaluando la influencia de la adición en la resistencia a compresión. Para ello han sido estudiadas seis composiciones de hormigón, divididas en dos dosificaciones: 1:1:2 y 1:2:3 (cemento: árido fino: grava) en peso, con relación a/c de 0,33 y 0,45. Para cada una de las mezclas se utilizaran concentraciones de 0, 0.3x10 8 or 1.2x10 8 de esporas de B. sutilis/mL. Los resultados obtenidos han demostrado que todas las muestras con adición de esporas presentaron precipitación de cristales, posiblemente carbonato de calcio, que fue visualizado en las fisuras. Más estudios microestructurales deberán ser realizados para comprobar que de hecho ocurrió el relleno de las fisuras. La resistencia a compresión presentó resultados satisfactorios, pues no hubo diferencias significativas en relación al hormigón de referencia, a nivel de 5% de probabilidad.Palabras clave: biohormigón; hormigón con adición de esporas; Bacilos subtilis; relleno de fisuras; fisuras.

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“…They have been exploited in many fields of engineering [10, 21,55], with a non-exhaustive list including: restoration of rock monuments [28,46,50], bioremediation and immobilisation of heavy metals [16-19, 22, 30, 54], shallow carbon sequestration [31,45], wastewater treatment [24], repair of fissures in concrete [4,43,57] and recovery of heavy oil from oil fields [15,20,38].…”

Section: Introductionmentioning

confidence: 99%

Feasibility of a soft biological improvement of natural soils used in compacted linear earth construction

et al. 2014

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Increasing demand for infrastructures requires innovative, cheap and environmental sustainable practices in construction. The soils which are available on site for linear embankments often need to be improved to satisfy the necessary performance and strength requirements. A bio-improvement is evaluated here, for use in compacted earth construction. To the aim of sustainability and cost reduction, a soft technique was chosen by the industrial party, which consisted in adding bacteria to a superficial soil retrieved in situ, and letting them precipitate calcium carbonate with the aid of the nutrients available in the organic matter of the soil and in the compaction water. The effects of the soft biological treatment on silty clayey sand were studied systematically in a comprehensive laboratory investigation, focused on the properties mostly affecting the performance of earth constructions: compaction energy, water retention, hydraulic conductivity, small-strain shear stiffness, collapse potential and shear strength. Mercury intrusion porosimetry tests and scanning electron microscopy were performed to help in providing a comprehensive picture of the consequences of the soft biological treatment on the natural soil. Lack in artificial nutrients reduces the efficiency of the biological treatment with respect to other cases reported in the literature. Nonetheless, organogenic aggregates and bonds are created during mixing and ageing, as detected from small-stiffness measurement during the curing time lapse. The bio-cemented bonds are mostly broken during compaction, while the aggregated structure remains, and the fine fraction generated by broken bonds ends in acting as filler of some inter-grain and interaggregate porosity. Eventually, the effects of the adopted technique on the hydro-mechanical behaviour of the compacted soil can be described in a coherent picture as the result of bio-filling of an aggregated compacted soil fabric.Peer ReviewedPostprint (published version

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Remediation of Concrete Using Microorganisms

Cited by 143 publications

References 0 publications

Selection of Nutrient Used in Biogenic Healing Agent for Cementitious Materials

Selection of Nutrient Used in Biogenic Healing Agent for Cementitious Materials

Crack filling in concrete by addition of Bacillus subtilis spores – Preliminary study

Feasibility of a soft biological improvement of natural soils used in compacted linear earth construction

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