Crack sealing evaluation of self-healing mortar with Sporosarcina pasteurii: influence of bacterial concentration and air-entraining agent

2021 ◽  
Author(s):  
Bingcheng Chen ◽  
Weiwei Sun ◽  
Xichen Sun ◽  
Chong Cui ◽  
Jianzhong Lai ◽  
...  
Keyword(s):  
Self Healing ◽  
Bacterial Concentration ◽  
Sporosarcina Pasteurii ◽  
Crack Sealing

scholarly journals Mechanical Recovery of Cracked Fiber-Reinforced Mortar Incorporating Crystalline Admixture, Expansive Agent, and Geomaterial

2019 ◽  
Vol 2019 ◽  
pp. 1-14 ◽  
Author(s):  
Abdul Salam Buller ◽  
Fahad ul Rehman Abro ◽  
Kwang-Myong Lee ◽  
Seung Yup Jang
Keyword(s):  
Water Flow ◽  
Mechanical Performance ◽  
Water Flow Rate ◽  
Self Healing ◽  
Test Results ◽  
Fiber Reinforced ◽  
Dissipation Energy ◽  
Expansive Agent ◽  
Strength Recovery ◽  
Crack Sealing

This research is sought to characterize the stimulated autogenous healing of fiber-reinforced mortars that incorporate healing agents such as crystalline admixtures, expansive agents, and geomaterials. The effects of the healing materials on mechanical performance and water permeability were evaluated experimentally. Furthermore, microscopic and microstructural observations were conducted to investigate the characteristics and physical appearance of healing products within healed cracks. Test results are presented herein regarding index of strength recovery (ISR), index of damage recovery (IDR) and index of dissipation energy gain (IDEG) in relation to crack healing, and reduction of water flow rate. The self-healing capability of the mortars was greater in terms of resisting water flow rather than recovering mechanical performance likely because water flow depends on surface crack sealing, whereas mechanical performance depends on bonding capacity as well as full-depth healing of cracks; thus, mechanical performance may further be improved after longer healing duration.

scholarly journals Performance requirements to ensure the crack sealing performance of bacteria-based self-healing concrete

2015 ◽  
Author(s):  
Eirini Tziviloglou ◽  
Virginie Wiktor ◽  
Henk Jonkers ◽  
Erik Schlangen
Keyword(s):  
Self Healing ◽  
Performance Requirements ◽  
Crack Sealing ◽  
Sealing Performance

scholarly journals Time-based and latitudinal assessment of contaminated and clean water quality on concrete strength

2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Ehizemhen C Igibah ◽  
Lucia Agashua ◽  
Abubakar Sadiq
Keyword(s):  
Concrete Strength ◽  
Hierarchical Cluster ◽  
Sewage Water ◽  
Calcium Lactate ◽  
Food Type ◽  
Self Healing ◽  
Multivariate Statistical ◽  
Ogun State ◽  
Crack Sealing ◽  
And Cluster Analysis

With increasing population and demand for infrastructural development in many developing countries, the demand for concrete has been on the increase and does not show any sign of slowing down in the nearest future. Existing concrete structures are also deteriorating and require repair or replacement. In this study, multivariate methods of factor analysis (FA) and cluster analysis (CA), were applied to analyze the liquefied samples datasets for clean and contaminated (sewage) water obtained in Ado- Odo Ota, Ogun State, Nigeria. FA clearly identified two groups of liquefied samples and indicated that the bacterial parameters are higher in fermented locust beans water which can be likened to presence of bacillus subtilis food type. Hierarchical cluster grouped 40 samples into two which are high and low levels of bacteria contents respectively. Descriptive statistics showed all parameters significantly (conductivity, TDS, BOD, COD, carbondioxide, Calcium, Chlorine, pH, Temperature, salinity) in Cluster A greater than in cluster B. The main self- healing parameter for crack sealing up, because when bacteria commence feeding on calcium lactate once activated, oxygen consumed as the bacteria feeds and insoluble limestone formed by conversion of the soluble calcium lactate is greater for contaminated water against portable water values. This study demonstrates the usefulness of multivariate statistical techniques for evaluation of presence of bacteria in liquefied samples before used as self-healing. Keywords— Carbondioxide, clean, self-healing concrete, water.

scholarly journals Self-healing bacterial cementitious concrete composites: development and performance evaluation

2021 ◽  
Author(s):  
Sini Bhaskar
Keyword(s):  
Compressive Strength ◽  
Bacillus Subtilis ◽  
Statistical Modelling ◽  
Energy Dispersive Spectrum ◽  
Ultrasonic Pulse Velocity ◽  
Pulse Velocity ◽  
Self Healing ◽  
Chloride Permeability ◽  
Sporosarcina Pasteurii ◽  
Subtilis Subsp

The principal objective of the research is to contribute towards attaining the goal of developing self-healing cementitious concrete composites by incorporating bacteria as healing agent. Since the root cause of the majority of structural failure is attributed to concrete cracking, there is a compelling economic incentive to develop a concrete that can treat and repair the damage all by itself. Even though some research has been carried out in this area, a major breakthrough in identifying the types of bacteria, modes to protect this bacteria from high pH concrete environment and nutrients for effective healing are yet to materialise. For the present study, three different bacteria namely, Sporosarcina ureae, Sporosarcina pasteurii and Bacillus subtilis subsp. spizizenii and two protective vehicles such as zeolite and pumice were selected to determine the best combination among them for self-healing. Normal and fibre reinforced mortar and engineered cementitious composite (ECC) specimens were employed for the study. In order to develop self-healing bacterial concrete based materials, it is crucial to understand whether the introduction of mineral producing bacteria and nutrients adversely affect the properties. Thus, various concentrations of bacteria and nutrients were tested to determine the best possible combinations without sacrificing concrete properies. Evaluation of healing effect was determined by comparing compressive strength, sorptivity and rapid chloride permeability (RCPT), four point bending and ultrasonic pulse velocity (UPV) properties of sound and damaged specimens at different ages. Healing associated with crack closure was visualised and analysed using scanning electronmicroscopy (SEM), Energy Dispersive Spectrum Energy (EDS) and X-ray diffraction (XRD) studies. Finally, an attempt was made to employ statistical models for parameter optimization of self-healing characteristics in terms of compressive strength, sorptivity, RCPT and UPV by design and analysis of experiments. Evaluation of results to determine self-healing efficiency indicated that a significant amount of self-healing was achieved by all three selected bacteria, out of which Sporosarcina pasteurii and Bacillus subtilis subsp. spizizenii found to be promising choices. Both zeolite and pumice turned out to be effective protective vehicles. Statistical modelling of the experiment proved to be the ideal choice for modelling self-healing characteristics.

Influence of bacterial concentration on crack self-healing of cement-based materials

2020 ◽  
Vol 244 ◽  
pp. 118372 ◽  
Author(s):  
Hui Rong ◽  
Guanqi Wei ◽  
Guowei Ma ◽  
Ying Zhang ◽  
Xinguo Zheng ◽  
...  
Keyword(s):  
Self Healing ◽  
Bacterial Concentration ◽  
Cement Based Materials

scholarly journals Ureolytic MICP-Based Self-Healing Mortar under Artificial Seawater Incubation

2021 ◽  
Vol 13 (9) ◽  
pp. 4834
Author(s):  
Xichen Sun ◽  
Jie Chen ◽  
Siyi Lu ◽  
Miaomiao Liu ◽  
Siyu Chen ◽  
...  
Keyword(s):  
Compositional Analysis ◽  
Fiber Surface ◽  
Healing Time ◽  
Artificial Seawater ◽  
Self Healing ◽  
Calcium Carbonate Precipitation ◽  
Sustainable Building ◽  
Sealing Capacity ◽  
Crack Sealing ◽  
Morphology Characterization

Ureolytic microbial-induced calcium carbonate precipitation (MICP) is a promising green technique for addressing sustainable building concerns by promoting self-healing mortar development. This paper deals with bacteria-based self-healing mortar under artificial seawater incubation for the sake of fast crack sealing with sufficient calcium resource supply. The ureolytic MICP mechanism was explored by morphology characterization and compositional analysis. With polyvinyl alcohol fiber reinforcement, self-healing mortar beams were produced and bent to generate 0.4 mm width cracks at the bottom. The crack-sealing capacity was evaluated at an age of 7 days, 14 days, and 28 days, suggesting a 1-week and 2-week healing time for 7-day- and 14-day-old samples. However, the 28-day-old ones failed to heal the cracks completely. The precipitation crystals filling the crack gap were identified as mainly vaterite with cell imprints. Moreover, fiber surface was found to be adhered by bacterial precipitates indicating fiber–matrix interfacial bond repair.

Evaluating the Self-Healing Efficiency of Hydrogel-Encapsulated Bacteria in Concrete

2020 ◽  
Vol 2674 (6) ◽  
pp. 113-123 ◽  
Author(s):  
Ahsennur Soysal ◽  
Jose Milla ◽  
Gary M King ◽  
Marwa Hassan ◽  
Tyson Rupnow
Keyword(s):  
Alginate Beads ◽  
The Self ◽  
Self Healing ◽  
Bacterial Strains ◽  
Crack Sealing ◽  
Healing Efficiency ◽  
Maximum Crack ◽  
Encapsulated Bacteria ◽  
Curing Regime ◽  
Bacterial Concrete

Bacterial concrete has become one of the most promising self-healing alternatives owing to its capability to seal crack widths through microbial-induced calcite precipitation (MICP). In this study, two bacterial strains were embedded at varying dosages (by weight of cement) in concrete. Beam specimens were used to quantify the maximum crack-sealing efficiency, whereas cylinder samples were used to determine their effects on the intrinsic mechanical properties of concrete, as well as its stiffness recovery over time after inducing damage. The concrete specimens were cured in wet–dry cycles to enable healing. Results showed that the specimen groups with the highest calcium alginate concentrations (including the control specimens with embedded alginate beads but no bacteria) resulted in the greatest increase in stiffness recovery. Similarly, the beam samples containing alginate beads (also including the Control 3%C specimen group) had superior crack-healing efficiencies to the control samples without alginate beads (Control NC). This was attributed to the alginate beads acting as a reservoir that can further enhance the autogenous healing capability of concrete. Based on the results of this study, further research is recommended to explore factors that can maximize the self-healing mechanism of bacterial concrete through MICP and determine whether an alternative encapsulation mechanism, nutrient selection, curing regime, or bacterial strain is needed.

scholarly journals Self-healing bacterial cementitious concrete composites: development and performance evaluation

2021 ◽  
Author(s):  
Sini Bhaskar
Keyword(s):  
Compressive Strength ◽  
Bacillus Subtilis ◽  
Statistical Modelling ◽  
Energy Dispersive Spectrum ◽  
Ultrasonic Pulse Velocity ◽  
Pulse Velocity ◽  
Self Healing ◽  
Chloride Permeability ◽  
Sporosarcina Pasteurii ◽  
Subtilis Subsp

The principal objective of the research is to contribute towards attaining the goal of developing self-healing cementitious concrete composites by incorporating bacteria as healing agent. Since the root cause of the majority of structural failure is attributed to concrete cracking, there is a compelling economic incentive to develop a concrete that can treat and repair the damage all by itself. Even though some research has been carried out in this area, a major breakthrough in identifying the types of bacteria, modes to protect this bacteria from high pH concrete environment and nutrients for effective healing are yet to materialise. For the present study, three different bacteria namely, Sporosarcina ureae, Sporosarcina pasteurii and Bacillus subtilis subsp. spizizenii and two protective vehicles such as zeolite and pumice were selected to determine the best combination among them for self-healing. Normal and fibre reinforced mortar and engineered cementitious composite (ECC) specimens were employed for the study. In order to develop self-healing bacterial concrete based materials, it is crucial to understand whether the introduction of mineral producing bacteria and nutrients adversely affect the properties. Thus, various concentrations of bacteria and nutrients were tested to determine the best possible combinations without sacrificing concrete properies. Evaluation of healing effect was determined by comparing compressive strength, sorptivity and rapid chloride permeability (RCPT), four point bending and ultrasonic pulse velocity (UPV) properties of sound and damaged specimens at different ages. Healing associated with crack closure was visualised and analysed using scanning electronmicroscopy (SEM), Energy Dispersive Spectrum Energy (EDS) and X-ray diffraction (XRD) studies. Finally, an attempt was made to employ statistical models for parameter optimization of self-healing characteristics in terms of compressive strength, sorptivity, RCPT and UPV by design and analysis of experiments. Evaluation of results to determine self-healing efficiency indicated that a significant amount of self-healing was achieved by all three selected bacteria, out of which Sporosarcina pasteurii and Bacillus subtilis subsp. spizizenii found to be promising choices. Both zeolite and pumice turned out to be effective protective vehicles. Statistical modelling of the experiment proved to be the ideal choice for modelling self-healing characteristics.

scholarly journals On the Applicability of a Precursor Derived from Organic Waste Streams for Bacteria-Based Self-Healing Concrete

2021 ◽  
Vol 7 ◽  
Author(s):  
Emanuele Rossi ◽  
Chris M. Vermeer ◽  
Renee Mors ◽  
Robbert Kleerebezem ◽  
Oguzhan Copuroglu ◽  
...  
Keyword(s):  
Calcium Carbonate ◽  
Service Life ◽  
Circular Economy ◽  
Organic Waste ◽  
Bacterial Activity ◽  
Self Healing ◽  
Waste Streams ◽  
Sealing Capacity ◽  
Crack Sealing ◽  
Healing Agent

Bacteria-based self-healing concrete has the ability to heal cracks due to the bacterial conversion of incorporated organic compounds into calcium carbonate. Precipitates seal the cracks, theoretically increasing the service life of constructions. The aim of this paper is to propose a precursor for bacteria-based self-healing concrete derived from organic waste streams, produced is in line with the circular economy principle and ideally more affordable than other substrates. To verify the applicability of the proposed healing agent, some fundamental requirements of the proposed system are studied, such as its influence on functional properties, crack sealing capacity and evidence of bacterial activity in concrete.

scholarly journals A Comparative Study On Self-Healing Methods of Concretes By Sporosarcina Pasteurii Bacteria

2021 ◽  
Author(s):  
Mohammad Mirshahmohammad ◽  
Hamid Rahmani ◽  
Mahdi Maleki-Kakelar ◽  
Abbas Bahari
Keyword(s):  
Culture Medium ◽  
Healing Process ◽  
Calcium Nitrate ◽  
Healing Time ◽  
Concrete Mixture ◽  
Bacterial Cells ◽  
Self Healing ◽  
Calcium Carbonate Precipitation ◽  
Sporosarcina Pasteurii ◽  
Biological Methods

Abstract Biological methods (adding bacteria to the concrete mixtures) among the most recently investigated procedures increase the durability of concrete and repair concrete cracks. In the present study, different biological methods were used to heal the cracks of concrete and the most suitable method was subsequently introduced. For this purpose, the culture medium and bacterial nutrient inside the concrete mixes and curing solution were separately studied. The effect of air-entrained agent and various sources of calcium salts as the bacterial nutrient on the healing process was also studied. The results showed that the use of bacterial nutrient inside the concrete mixes has an affirmative impact on the mechanical properties and self-healing characteristics of concretes. With the simultaneous use of Sporosarcina pasteurii bacteria and calcium nitrate-urea or calcium chloride-urea as a bacterial nutrient in the concrete mixture, the 28 days compressive strength of concrete increases by 23.4% and 7.5%, respectively, which is due to calcium carbonate precipitation. The use of bacterial cells, nutrients, and culture in the concrete mixture provided the ability to heal wide cracks where the healing time is significantly reduced. On the other hand, separation of the bacterial culture medium slightly reduced the self-healing performance of concrete.

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