Characteristics of Soybean Urease Mineralized Calcium Carbonate and Repair of Concrete Surface Damage

Fan, Ya-Nan; Du, Hong; Wei, Hong

doi:10.1007/s11595-021-2379-9

Cited by 6 publications

(5 citation statements)

References 19 publications

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“…At 300 °C, 400 °C, 500 °C, and 600 °C, the average infrared temperature increase in specimens repaired by the immersion method decreased by 77%, 80.93%, 78.39%, and 79.27%, respectively. This is consistent with the result obtained by Fan et al [ 34 ]. However, the corresponding decline by negative pressure method is 80.49%, 85.56%, 81.41%, and 80.99%, respectively.…”

Section: Resultssupporting

confidence: 94%

“…The repair solution is runny, and gravity plays an important role in the deposition of sediments; more sediments are deposited on the upper surface than on the sides, so the film thickness of the upper surface is thicker than that of the sides. Fan et al [ 34 ] also mentioned the significant stratification phenomenon in her paper, but she has not explained the reason. This may be due to the different crystals of the sediments from two layers; the weight of different crystals is also different, as they will be stratified under the action of gravity, with the heavy crystals on the bottom while the light crystals are on the surface.…”

Section: Resultsmentioning

confidence: 94%

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Experimental Study on High-Temperature Damage Repair of Concrete by Soybean Urease Induced Carbonate Precipitation

et al. 2022

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In this study, the effects of soybean-urease-induced carbonate precipitation on a high-temperature damage repair of concrete were explored. C50 concrete specimens were exposed to high temperatures from 300 to 600 °C, then cooled to an ambient temperature and repaired by two different methods. The influences of the damage temperature and repair methods on surface film thickness, average infrared temperature increase, water absorption, and compressive strength were investigated. Scanning electron microscopy (SEM) images were carried out to further study the mechanism involved. The results revealed that the white sediments on the surface of the repaired specimens were calcium carbonate (CaCO3) and calcium oxalate (CaC2O4). The surface film thickness reached up to 1.94 mm after repair. The average infrared temperature increase in the repaired specimens at different damage temperatures was averagely reduced by about 80% compared with that before the repair. It showed more obvious repair effects at higher temperatures in water absorption and compressive strength tests; the compressive strength of repaired specimens was 194% higher than that before repairs at 600 °C. A negative pressure method was found to be more effective than an immersion method. This study revealed the utilization of SICP on repairing high-temperature damage of concrete is feasible theoretically.

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Section: Resultssupporting

confidence: 94%

Section: Resultsmentioning

confidence: 94%

Experimental Study on High-Temperature Damage Repair of Concrete by Soybean Urease Induced Carbonate Precipitation

et al. 2022

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“…The load P in Equation ( 3) is taken at the maximum displacement. The relationship between the approximate modulus of elasticity Er and the modulus of elasticity E of the material is given in Equation (11):…”

Section: Mechanical Properties Of Nanoindentation Of Mineralisation P...mentioning

confidence: 99%

“…The ability of Sporosarcina pasteurii to induce calcium carbonate precipitation is mainly attributed to two main features. The most important feature is the ability of Sporosarcina pasteurii to secrete highly active urease, which catalyses the decomposition of urea within the bacterium by virtue of its highly efficient urease activity [11][12][13][14][15], rapidly increasing the carbonate concentration and pH of the microenvironment around the bacterium; second, it has been shown that the surface of Sporosarcina pasteurii, including the cell wall and extracellular polymers, has a greater number of negative surface charges and thus can more strongly adsorb cations than the surface of nonmineralised bacteria [16], so positively charged Ca 2+ in the environment can be adsorbed in large quantities. Under high concentrations of carbonate and alkaline conditions, Ca 2+ then settles to form CaCO 3 crystals using cells as nuclei.…”

Section: Introductionmentioning

confidence: 99%

The Effect of Bacteria-to-Calcium Ratio on Microbial-Induced Carbonate Precipitation (MICP) under Different Sequences of Calcium-Source Introduction

Zhao,

Du,

Shang

2024

Materials

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To explore the effects of the introduction order of calcium sources and the bacteria-to-calcium ratio on the microbially induced calcium carbonate precipitation (MICP) product CaCO3 and to achieve the regulation of CaCO3 crystal morphology, the mineralisation products of MICP were compared after combining bacteria and calcium at ratios of 1/9, 2/9, 3/9, 4/9, 5/9, and 6/9. A bacterial solution was combined with a urea solution in two calcium addition modes: calcium-first and calcium-later modes. Finally, under the calcium-first addition method, the output of high-purity vaterite-type CaCO3 was achieved at bacteria-to-calcium ratios of 2/9 and 3/9; under the calcium-later addition method, the output of calcite-type CaCO3 could be stabilised, and the change in the bacteria-to-calcium ratio did not have much effect on its crystalline shape.

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“…The results of the conducted research show that exposing concrete to high temperatures reduces the mechanical properties and durability and triggers surface cracks, which could be developed in different directions [35][36][37][38]. As a result, repairing thermal cracks in concrete is essential, especially for fire exposed concrete structures.…”

Section: Introductionmentioning

confidence: 99%

Use of Bacteria Externally for Repairing Cracks and Improving Properties of Concrete Exposed to High Temperatures

Nimafar¹,

Samali

Hosseini

et al. 2021

Crystals

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The current paper presents the results of an experimental study on the application of calcium carbonate precipitation bacteria as a new approach to repairing damaged concrete when exposed to high temperatures. To do so, cylindrical and cubic concrete specimens were initially exposed to heat in a furnace for 1 h, after reaching two different temperatures of 600 and 800 °C. A heat rate of 5.5 °C per minute was used to achieve the target temperatures. Then, two types of bacteria, namely Sporosarcina pasteurii and Bacillus sphaericus, with cell concentration of 107 cells/mL, were utilized externally, to repair the thermal cracks, enhancing the mechanical properties and durability of the damaged concrete. The efficiency of the bacterial remediation technique was then evaluated through compressive strength, ultrasonic pulse velocity (UPV), and electrical conductivity tests on the control specimens (unexposed to heat), and those exposed to high temperature with or without bacterial healing. The experimental results demonstrate that the compressive strength of the test specimens exposed to temperatures of 600 and 800 °C decreased by about 31–44% compared with the control ones. However, compared to those damaged at 600 and 800 °C, the compressive strength of specimens repaired by the S. pasteurii and the B. sphaericus showed increases of 31–93%. This increase is associated with the precipitation of calcium carbonate in the deep and superficial cracks and pores of the damaged specimens. Furthermore, the ultrasonic pulse velocity of the specimens subjected to bacterial remediation had a significant increase of about 1.65–3.47 times compared with the damaged ones. In addition, the electrical conductivity of repaired specimens decreased by 22–36% compared with the damaged specimens.

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Characteristics of Soybean Urease Mineralized Calcium Carbonate and Repair of Concrete Surface Damage

Cited by 6 publications

References 19 publications

Experimental Study on High-Temperature Damage Repair of Concrete by Soybean Urease Induced Carbonate Precipitation

Experimental Study on High-Temperature Damage Repair of Concrete by Soybean Urease Induced Carbonate Precipitation

The Effect of Bacteria-to-Calcium Ratio on Microbial-Induced Carbonate Precipitation (MICP) under Different Sequences of Calcium-Source Introduction

Use of Bacteria Externally for Repairing Cracks and Improving Properties of Concrete Exposed to High Temperatures

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