Bacterial Concrete Research Articles

Study on the tensile strength of plastic fiber reinforced M20 grade self-compacting bacterial concrete using a novel microbial technique Microbial induced calcite precipitation

Aim: The objective of this study is to quantify the influence of plastic fiber on the tensile strength of self-compacting concrete using a novel microbial technique Microbial induced calcite precipitation. Materials and Methods: There are 2 groups taken for the study and a total of 18 samples were prepared per group with Gpower (80%). Group-1 refers to the conventional self-healing concrete and group-2 refers to the plastic fiber reinforced self-compacting. concrete. The number of samples was calculated using clinical software by adopting the values from previously published research papers. The independent sample T-test has been carried out using SPSS software version 21 which shows a clear increment in the tensile strength of the fiber reinforced self-compacting concrete. Result: Tensile strength of plastic fiber reinforced self-compacting concrete increased by 3.73% when compared with the normal self-compacting concrete. The standard deviation of the tensile strength of plastic reinforced bacterial concrete was 0.28965. A significant difference between the two groups was observed with a p-value of 0.010 (p<0.05) Conclusion: From this experimental study it is concluded that the plastic fiber reinforced M20 grade self-healing concrete has greater tensile strength than the normal self-compacting concrete.

Study on the Flexural Strength of Glass Fiber Reinforced M20 Grade Self-Compacting Bacterial Concrete

Aim: The goal of this research is to determine the effect of glass fibre on the flexural strength of M20 grade self-healing concrete utilising a unique approach called microbial induced calcite precipitation.. Materials and methods: For data collection, two groups of 18 samples each were produced. The first group is formed without the presence of glass fibre, whereas the second group is formed with the presence of glass fibre. Bacillus subtilis bacteria were cultured in the bioinformatics laboratory using a strain obtained from Hi media laboratories. Results: SPSS statistical software was used to analyse the data. The mean flexural strength of bacterial concrete without fibre was 7.944 N/ mm2, while Glass fibre reinforced concrete had a mean flexural strength of 8.666 N/mm2. The events had a significance of 0.00 (p<0.05). Conclusion: The flexural strength of glass fibre reinforced M20 grade self-healing concrete was higher than that of conventional M20 grade self-healing concrete prepared utilising a unique process of microbial induced calcite precipitation. The strength of Glass fibre reinforced M20 grade self-healing concrete increased by 9 percent.

A review of durability improvement in concrete due to bacterial inclusions

Since the invention of industrially produced Portland cement in the nineteenth century, concrete has been the world’s most frequently used construction material. Because of the significant CO2 emissions produced during cement manufacture and concrete maintenance and repair costs, sustainably improving concrete durability has become a topic of concern. Bacterial self-healing is a unique method that uses CaCO3 precipitation to repair cracks in concrete, thereby improving the structure’s durability. This review highlights the effect of bacterial treatment on concrete durability. The permeation properties, water absorption, and mechanical properties are assessed. Emphasis is laid on the selection of bacteria and bacteria nutrients. The paper overviews the morphological analysis of CaCO3 precipitation by bacterial concrete. Despite the benefits of bacterial technology in concrete, numerous critical concerns remain unresolved. Further investigation on nutrients is required to develop a multi-nutrient system that will improve the efficiency of bacterial precipitation since a good combination of low-cost nutrients would reduce the total cost of bacterial concrete.

Self-Healing Concrete by Microorganisms in the Altered Pozzolan of Madagascar with Calcium from Crab Wastes

Concrete is at a high risk of cracking which threats its durability. Self-healing bacterial concrete has been developed in recent years to tackle this issue and its effectiveness has been massively studied. However, bacteria need carriers and expanded clay is the most used as such, but it reduces concrete strength. Moreover, bacterial culture and immobilization processes are highly expensive; calcium salts also contribute to the high cost of this type of concrete. This work therefore aims to overcome these limitations. Calcium salts were collected from the chitosan production process from crab waste. In addition, we noticed that Betafo pozzolan contains an abundant number of microorganisms, and for the first time, we discovered that those microorganisms have polyextremophilic characters, are resistant to various sterilization methods, and allow the self-healing concrete process. We concluded that calcium salts from the crab, with those microorganisms are able to heal crack up to 350 µm wide, reducing the expenses related to nutrients, and eliminating those related to the growth and the immobilization of bacteria on carrier. Moreover, we pointed out that pozzolan significantly increases compressive strength by 90.04%. However, the behavior of those microorganisms and the pozzolanic reactions need to be further investigated.

Application of soft computing techniques for the prediction of splitting tensile strength in bacterial concrete

ABSTRACT Concrete is the most common building material used in construction activities, but concrete cracks are inevitable thus is one of its major disadvantages. The major downside of the concrete is its lower Splitting Tensile Strength (STS) attributable to the micro crack. Bacteria have recently been utilized to self-heal concrete, treat cracks, and consolidate different construction materials. However, since the testing of the mechanical properties of concrete is time-consuming, involves destructive methods, poses material wastage, and is labor-intensive, an alternative precise strength evaluation technique is required to minimize effort and time. In the current investigation, various computational techniques, such as M5P, Random Forest (RF), Support vector machine (SVM), and Linear regression (LR), were used to predict the splitting strength of concrete using experimental datasets. The Pearson VII kernel function-based SVM (SVM-PUK) strategy was determined to be the most effective and accurate technique to predict the splitting strength value compared to other used models using Correlation Coefficient (CC) values based on statistical assessments, Box plot, and Taylor diagram. Results of the sensitivity analysis, among the other input variables used in this study to predict concrete splitting strength, reveal that curing time in days (T) is the most significant variable.

Study on the compressive strength of glass fibre reinforced M20 grade self-healing concrete using a novel technique microbial induced calcite precipitation

• A novel MICP (Microbial Induced Calcite Precipitation) is used to quantify the compressive strength of glass fiber reinforced self healing concrete. • Statistical analysis presents a significant impact of impact strength. • Glass fiber reinforced concrete had more strength compared to bacterial concrete, The objective of the study was to quantify the compressive strength of glass fiber reinforced self healing concrete using a novel MICP (Microbial Induced Calcite Precipitation). The total sample size was 24. It was calculated using clincalc software. In this software G power and alpha was set as 95 % and 0.05 respectively. Two groups consisting of 18 samples each were prepared for the collection of data. One is prepared with the addition of glass fibre and the other is without fiber. Bacteria Bacillus subtilis was prepared in the bioinformatics laboratory using a strain brought from the hi media laboratories. The data was analysed using a statistical software SPSS, version 21. The mean compressive strength of glass fiber reinforced concrete was 30.8074 N/mm 2 and the compressive strength of bacterial concrete without fiber was 27.6445 N/mm 2 . Independent samples t -test is performed to analyse the results. The significance (p) value obtained was 0.107 (p > 0.05) suggesting that there is no statistical significant difference. The standard deviation of glass fiber reinforced bacterial concrete was 2.51687. The glass fiber reinforced concrete had more strength compared to bacterial concrete. The percentage increase in strength of glass fiber reinforced concrete was 11.44 %.

Mechanical Properties of Bacterial Concrete by Partial Replacement of Cement by Nano Silica in Different Grades of Concrete

Concrete with nano-silica also has a higher strength compared with normal concrete. In the current study, an examination of the mechanical characteristics of bacterial concrete containing nano-silica is conducted. The impact of concrete was examined in this study employing Bacillus subtilis for self-Healing Microbial Type Culture Collection (MTCC) Strain no.121, Among the bacteria concentrations of 104 , 105 , and 106 cells/ ml, a concentration of 105 cells/ml gives more strength, so further investigation is done using 105 cells/ml cell concentration for different percentages of nano-silica is examined. Firstly, Bacterial cell concentration is optimised. Each of the 40 sets of cubes (150 mm x 150 mm x 150 mm), cylinders (150 mm diameter and 300 mm height), and prisms (100 mm x 100 mm x 500 mm) are cast and tested at 28 days and 90 days as part of further research to determine the mechanical properties of bacterial concrete with different percentage of nano silica with and without bacteria. It has been noted that adding nano-silica to concrete increases its strength from 0% to 1.5% before being decreased to 2%. concrete splintering occurs due to a number of causes, including mechanical compression and low tensile strength, shrinkage, freeze-thaw reaction, and others. External loads can cause high tensile strains. For any combined nano-silica percentage when compared to regular concrete, bacterial concrete is stronger.

Experimental investigation on mechanical properties and characterization of steel fibre concrete with Bacillus subtilis

Building cracks spoil the aesthetic view of the structure along with degrading the strength of the structure. It leads to the failure of the structure as a whole. Propagation of cracks in the concrete surface increases the chance of permeability due to moisture content in the atmosphere which might corrode the internal reinforcements. To overcome this situation, a solution in the form of fibre-reinforced self-healing concrete was suggested in this research work. Steel fibre was added by varying 0%,1%,2%,3%,4% and 5% interms of volume of concrete to prolong fatigue life and decrease the crack width under fatigue loading. Bacteria (Bacillus subtilis) are used to heal the cracks by producing calcium carbonate (CaCO3) as a result. Bacterial concrete with fibre (BCF) was cast by M30 mix as per Indian Standard Code. Studied concrete's mechanical and microstructural properties like compression strength test, flexural strength test, split tensile strength test, SEM images, EDS, XRD and FTIR methods. From microstructural studies, it is clear that there is sufficient self-healing material in broken concrete, hence the efficiency of BCF's self-healing property is commendable and the ability of the generated BCF concrete to regain strength.

Osvrt na samozaceljujući beton - biološki pristup

Concrete is one of the most popular and used construction materials. It is strong, durable, and relatively inexpensive, but it has a higher tendency to form cracks. The cracks provide a low service life for the concrete and high maintenance costs. The penetration of aggressive ions through cracks results in corrosion of steel reinforcement, carbonation, sulphate attack, alkali-aggregate reaction, etc. However, prevention of cracks formation is impossible, however, they can be controlled or repaired by various methods. Self-healing concrete is well known as a suitable remedial method to improve concrete's long-term durability. It is a new, rapid, and environmentally friendly approach. In this technology, when concrete is exposed to water, the healing agent material produces calcium carbonate (CaCO3), which fills in the cracks and decreases permeability while enhancing concrete durability. The materials that are used as the healing agents are mostly bacteria, polymers, and chemical compounds. Bacteria are the most preferred material in concrete for healing. Therefore, bio concrete or bacterial concrete is another name for self-healing concrete. This article provides a comprehensive overview of self-healing concrete including, the system, process, mechanical properties, and durability of healed concrete.

Performance of Bacillus Cohnii Added Microbial Concrete

In the era of rapid urbanization, concrete has been playing a very important role in construction industry but inherently, it is very much vulnerable to formation of cracks, due to which its durability gets decreased. If immediate action is not taken, cracks developed in the section may spread further and increase the cost of repair. In concrete structures, these cracks become an easy path of entry for water, oxygen and carbon dioxide resulting into the decrease in durability of concrete. Numerous researches around the world are on to heal this defect with the help of addition of various bacteria in the form of Bacterial Concrete. This study aims to find out the change in salient properties of concrete experimentally after adding the microbes. Concrete cubes were cast with different bacteria concentrations, tested for salient properties after 7 and 28 days. Test results reveal that addition of bacteria results into increase in compressive strength and decrease in water absorption and porosity of concrete. Findings also indicate that the concrete mix with higher bacteria concentration gives higher compressive strength and lower water absorption and porosity in concrete.

Study on bacteria based self-healing properties of bio-concrete - An overview

The use of bacteria-based self-healing concrete has gained attention in recent years due to its potential to improve the durability and sustainability of concrete structures. This paper provides an overview of the research conducted on the self-healing properties of bacteria-based bio-concrete. The paper discusses the mechanism of bacterial self-healing in concrete, the types of bacteria used in self-healing concrete, and the methods used to introduce bacteria into the concrete. The paper also reviews comparative studies that evaluate the mechanical properties and durability of selfhealing bacterial concrete compared to traditional concrete. The results of these studies demonstrate that the use of bacteria in concrete can improve the self-healing capacity of the material, leading to better mechanical properties and a higher resistance to cracking and freeze-thaw damage. Furthermore, the paper discusses the potential environmental and economic benefits of using self-healing bacterial concrete. The self-healing capacity of the concrete can reduce the need for costly repairs and maintenance of concrete structures, resulting in lower costs and a reduced environmental impact associated with concrete production. Additionally, the use of waste materials as nutrient sources for bacteria can promote the circular economy and contribute to sustainable development. Overall, this paper highlights the promising potential of self-healing bacterial concrete to improve the durability, sustainability, and economic viability of concrete structures.

Smart self-healing bacterial concrete for sustainable goal

Smart self-healing bacterial concrete for sustainable goal

Effect of basalt fibers on the mechanical and self-healing properties of expanded perlite solid-loaded microbial mortars

Microbial-induced calcium carbonate precipitation (MICP) is an environmentally friendly technology to repair cracks. In this study, expanded perlite was used to adsorb bacteria as a self-healing agent, and basalt fibers were used for the first time to enhance the healing effect of microbial mortar. The mechanical properties and impermeability of fiber-reinforced bacterial concrete were investigated, the macroscopic crack healing effect and the precipitation path of generates were observed by optical microscopy, and the coupling effect of fibers and bacteria was studied and revealed by microscopic experiments. It was shown that the addition of a self-healing agent made the self-healing performance of mortar significantly enhanced, and the incorporation of fibers enhanced the mechanical properties and impermeability of the mortar. The basalt fibers provided the location for calcium carbonate precipitation, and its bridging action provided the pathway for precipitation. The fibers offered the possibility of healing cracks larger than 300 μm in width.

Optimization of the Self-Healing Efficiency of Bacterial Concrete Using Impregnation of Three Different Precursors into Lightweight Aggregate

Implementation of self-healing concrete technologies is a promising approach to enhance the durability of the transportation infrastructure. Among these technologies, bacterial concrete has the potential to seal microcracks through microbial-induced calcite precipitation (MICP). To ensure the viability of this technology, bacterial protection is essential given concrete’s harsh environment. Additionally, the success of this technology depends on the presence of an adequate mineral precursor compound and nutrient for the bacteria. As such, the main objective of this study was to optimize the healing efficiency of bacterial concrete in subtropical climates through the vacuum impregnation of bacteria into a lightweight aggregate (LWA). To achieve this objective, mortar samples were prepared while incorporating different combinations of precursors (magnesium acetate, calcium lactate, and sodium lactate) and alkali-resistant healing agent Bacillus pseudofirmus bacteria (with and without). In addition, a control sample was prepared without bacteria or precursors for comparative purposes. For each sample, three mortar cubes and three mortar beams were cast and used to evaluate the compressive strength, crack healing efficiency, and flexural strength recovery. Additionally, the morphology of healing products was observed in bacteria-containing samples under scanning electron microscopy with energy x-ray dispersive spectroscopy using a scanning electron microscope (SEM) with EDAX Pegasus energy dispersive spectroscopy (EDS). Results showed that self-healing bacterial concrete could be optimized (without significant reduction in mechanical properties) if Bacillus pseudofirmus bacteria at a concentration of 108 cells/ml and sodium lactate precursor at a concentration of 75 mM/l were impregnated into lightweight aggregate.

Performance Evaluation of Bio Concrete by Cluster and Regression Analysis for Environment Protection.

The focus of this research is to isolating and identifying bacteria that produce calcite precipitate, as well as determining whether or not these bacteria are suitable for incorporation into concrete in order to enhance the material's strength and make the environment protection better. In order to survive the high “potential of hydrogen” of concrete, microbes that are going to be added to concrete need to be able to withstand alkali, and they also need to be able to develop endospores so that they can survive the mechanical forces that are going to be put on the concrete while it is being mixed. In order to precipitate CaCO3 in the form of calcite, they need to have a strong urease activity. Both Bacillus sphaericus and the Streptococcus aureus bacterial strains were evaluated for their ability to precipitate calcium carbonate (CaCO3). These strains were obtained from the Department of Biotechnology at GLA University in Mathura. This research aims to solve the issue of augmenting the tension and compression strengths of concrete by investigating possible solutions for environmentally friendly concrete. The sterile cultures of the microorganisms were mixed with water, which was one of the components of the concrete mixture, along with the nutrients in the appropriate proportions. After that, the blocks were molded, and then pond-cured for 7, 28, 56, 90, 120, 180, 270, and 365 days, respectively, before being evaluated for compressibility and tensile strength. An investigation into the effect that bacteria have on compression strength was carried out, and the outcomes of the tests showed that bacterial concrete specimens exhibited an increase in mechanical strength. When compared to regular concrete, the results showed a maximum increase of 16 percent in compressive strength and a maximum increase of 12 percent in split tensile strength. This study also found that both bacterial concrete containing 106, 107, and 108 cfu/ml concentrations made from Bacillus sphaericus and Streptococcus aureus bacteria gave better results than normal concrete. Both cluster analysis (CA) and regression analysis (RA) were utilized in this research project in order to measure and analyze mechanical strength.

Study of microstructural analysis (MSA) on properties related to strength and its characteristics on bacterial concrete

Cement Concrete broadly used in building material for all civil engineering applications due to its well-known In India Conventional Cement Concrete (CCC) are used in growth of construction. Concrete is liable to create a micro crack while substituting by building materials and consumes pores which are highly unwanted because of were they afford an open pathway for water and other poisonous substances. In way to improve more durable for the structure it is better to take HPC. It is also a cement concrete which has far bigger strength and durability features compared to CCC. HPC does not mean only achieving the detailed compressive strength but also other parameters such as im-permeability, resistance to environmental factors, shrinkage, corrosion resistance, electrical resistivity etc. In this study the mineral admixtures are to add. such they are silica fume, ground granulated blast furnace slag, rice husk ash, fly ash and highly reactive metakaolin in and also have a look on improvement in the micro-structure of concrete in various complexes. The bacterial degradation technique is eco-friendly and durable. Bacteria need to resist withstand high pH of concrete and mechanical stresses during mixing. Based on the data collection of literature that, information available that different bacterial samples namely Bacillus Megaterium (BM), Bacillus Subtilis (BS) and Pseudomonas Aeruginosa (PA) are considered in concentrations of 104, 105 and 106 cells/ml of mixing of water. M30 grade concrete is designed and used for embedding different types of bacteria. In this dissertation, investigations are carried out on strength-related possessions such as compressive strength, splitting tensile strength, flexural strength, modulus of elasticity and bond strength.

Efficacy of Bacterial Concrete with Conventional Concrete

Abstract: Concrete is one of the maximum used building substances. But, it is one of the predominant manufacturers of carbon dioxide (CO2) that's immediately contributing to destroying our surroundings. Not to say that significant costs are being spent each year to keep concrete structures. Cracks of numerous sizes shape in all concrete structures which need to be sealed manually shortening the life of a particular construction. However, Self-healing concrete (SHC) is a innovative constructing material that has the answer to these kind of troubles and is the constructing fabric of the near destiny. Therefore, we want to apprehend its homes and mechanism and foresee how it impacts the architectural designs of the time to come back, and which standers are had to create useful and aesthetic homes and buildings. It's been proven that a number of the present day concrete remedy strategies together with the software of chemical substances and polymers are a supply of fitness and environmental dangers, and greater importantly, they are powerful best within the quick term. As a result, treatment techniques which are environmentally pleasant and lengthy-lasting are in high call for. A microbial self-restoration method is distinguished by way of its capacity for long-lasting, fast, and lively crack restore, even as also being environmentally pleasant.

Health monitoring of bacterial concrete structure under dynamic loading using electro-mechanical impedance technique: a numerical approach.

Health monitoring of structures using techniques based on the smart material is an innovative concept that is exploding technological revolutions in the field of civil engineering. The electro-mechanical impedance (EMI) technique is used for structural health monitoring (SHM) and to investigate the damages in the structures. The bacterial incorporation in concrete produces calcite material through metabolism process in presence of moisture and carbon dioxide, which improves the mechanical properties of concrete. Hence, its application in construction of the buildings will improve the health of structures. In this research paper, dynamic behaviour of the bacterial concrete was investigated numerically. The beams of size 700 × 150 × 150mm of bacterial concrete and control concrete were modelled using finite element-based package ANSYS19. The beam of bacterial concrete was simulated as per the characteristics of the materials produced after the bacterial metabolism reactions. The EMI technique was applied to investigate the health of these beams. Admittance (conductance and susceptance) signatures were determined using piezo-ceramic lead zirconate titanate (PZT) sensors installed at mid-point on the top surface of concrete beams. The beams were exposed to dynamic loading and the intensity of dynamic loading was increased in four sub-steps. For the quantification of strength development in the concrete beam, the root mean square deviation (RMSD) statistical index had been applied. It was observed that the bacterial concrete beam has more resistance to the dynamic loading.

Effects of Various Pseudomonas Bacteria Concentrations on the Strength and Durability Characteristics of Concrete

The goal of this study is to improve concrete’s efficiency by using a microbiologically produced specific growth/filler. One such way of thinking has resulted in the invention of a highly unusual concrete known as microbial concrete, which uses bacteria to cure flaws in the concrete. Investigators working with various microorganisms suggested several microbial concretes. The bacterium “Pseudomonas” was used in this experiment. Pseudomonas bacteria, which can make calcite precipitates on a proper medium supplied with a calcium supply, is a typical science lab bacterium for calcite generation. Two different concentrations (106 cfu/mL and 107 cfu/mL) of bacteria were added to cement concrete and it was observed that the bacterial concrete with two different concentrations gives results as compared with normal concrete. According to the findings of this investigation, the inclusion of bacteria resulted in a considerable increase in compressive strength when the dilution factor was 106 cells per ml of mixed water. With the incorporation of the microorganisms, it was discovered that holes were partly filled up by material growth, as shown by scanning electron micrography inspection of the sample. Concrete cubes without and with the inclusion of bacteria were molded, and it was discovered that the compressive strength of the cubes with the injection of microorganisms increased significantly. In this study, concrete cylinders without and with the inclusion of microorganisms were molded, and it was discovered that the split tensile strength of the cylinders with the injection of microorganisms increased significantly above the control. When compared with regular concrete, the results showed a maximum increase of 16 percent in compressive strength and a maximum increase of 12 percent in split tensile strength. It was discovered via durability testing that bacterial concrete had less weight loss and stronger tensile strength than conventional concrete when treated with 5 percent H2SO4 or 5 percent MgSO4 compared with control concrete.

Bacterial Performance in Crack Healing and its Role in Creating Sustainable Construction.

Building practices began with human civilization. Cement is the most commonly used building construction material throughout the world. These traditional building materials have their own environmental impact during production, transportation, and construction, but also have limitations on building quality and cost. Biological construction materials are currently emerging technology to combat emissions from the construction sector. Different civil and biotechnology researchers have turned to microorganisms for the production of bio construction materials that are environmentally friendly, socially acceptable, and economically feasible but can also produce high strength. Scanning electron microscope (SEM) and X-Ray diffraction (XRD) are the most characterization methods used to observe and ensure the production of calcite precipitate as bacterial concrete. As compared to conventional concrete, bacterial concrete was greater by 35.15% in compressive strength, 24.32% in average tensile strength, and 17.24% in average flexural strength, and it was 4 times lower in water absorption and 8 times lower in acid resistivity than conventional concrete. Genetic engineering has great potential to further enhance the mechanical strength of bacterial concrete for use in crack repairs in existing buildings.