Utilization of Soybeans as Bio-Catalyst in Calcite Precipitation Method for Repairing Cracks in Concrete

2021 ◽  
Vol 23 (2) ◽  
pp. 104-113
Author(s):  
Rama Zaky Rahmawan ◽  
Muhammad Fauzan ◽  
Heriansyah Putra
Keyword(s):  
Compressive Strength ◽  
Precipitation Method ◽  
Carbonate Precipitation ◽  
Self Healing ◽  
Soybean Flour ◽  
Injection Solution ◽  
Calcite Precipitation ◽  
Soybean Extract ◽  
Urease Enzyme ◽  
Lower Tensile Strength

Concrete is a material that has high compressive strength. However, concrete has a lower tensile strength than its compressive strength. As a result, the concrete often cracks and allows the entry of harmful substances such as  dan   causing corrosion of the reinforcement. Therefore, the repair method began to shift from the conventional way to the concept of self-healing concrete which involves the deposition of CaCO3. Precipitation can be done by the enzymatically – induced carbonate precipitation (EICP) method through a combination of urease, urea, and CaCl2 into a solution. This research used soybean extract as a substitute for pure urease enzyme. Variations in the concentration of soybean flour used as injection solution were variations in the content of soybean flour 15 g/L because it produced an optimum calcite mass of 2.62 grams. As a result, there was an increase in the compressive strength of BI against BR. In addition, there was a decreased value of permeability and porosity and the number of injections carried out. The increase in compressive strength, decrease in permeability, and decrease in porosity in concrete is due to CaCO3 deposition in the concrete which can cover the pores and cracks in the concrete.

scholarly journals Effect of Bacteria Inoculums on Compressive Strength

2021 ◽  
Vol 8 (2) ◽  
pp. 59-63
Author(s):  
Pooja Bandekar ◽  
Sandhay Basavaraj ◽  
Prakash Mallappa Munnoli ◽  
Jyoti Gupta ◽  
Geeta Shetteppanavar ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Cement Mortar ◽  
Culture Collection ◽  
Self Healing ◽  
Cement Concrete ◽  
Calcite Precipitation ◽  
Chain Reaction ◽  
Colony Forming Units ◽  
Polymerase Chain ◽  
Strength And Durability

The use of bio-concrete is increasing in the present day context and researchers are working on strength and durability characteristics of concrete using bacteria species which have shown calcite precipitation. Three different species of bacteria namely P. Fluorescence, B. Pumilis and B. Subliis that have calcite precipitation properties have been investigated in this study. The investigations were carried first on cement mortar (CM) cubes using these three bacteria species suspension of 20%; 40% and 60% having colony forming units P. Fluorescence (108 CFU/ml), B. Pumilis (106 CFU/ml) and B. Subtilis (108 CFU/ml) respectively. The 40% suspension in all the three cases has shown increased compressive strength as compared to 20% and 60%. The compressive strength measured showed increase (CS) of 18%; 12% for P. Fluorescence; B. Subtilis and decrease of 35% with B. Pumilis respectively. B. Subtilis with optimized 40% suspension having CFU 10x108/ml showed 4.32% ; 5.56%; and 3.81% increase in CS of CC cubes with 3 days; 7 days and 28 days respectively and 5.92% overall increase in CS of CC cubes as compared to the 3 days CS of control cube. ABBREVIATIONSSDW: Sterile Distilled Water; SHC: Self-Healing Concrete; PCR: Polymerase Chain Reaction; BC: Bacterial Concrete; CP: Calcite precipitation; CS: Compressive Strength; CC: Cement Concrete; CM: Cement Mortar; MTCC: Microbial Type Culture Collection; CFU: Colony Forming Unit/ml

scholarly journals Optimization of Bio-Foamed Concrete Brick Strength via Bacteria Based Self-Healing and Bio-Sequestration of CO2

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4575
Author(s):  
Abdullah Faisal Alshalif ◽  
J. M. Irwan ◽  
Husnul Azan Tajarudin ◽  
N. Othman ◽  
A. A. Al-Gheethi ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Co2 Concentration ◽  
Optimization Methods ◽  
Self Healing ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
X Ray ◽  
Sequestration Of Co2 ◽  
Urease Enzyme ◽  
Foamed Concrete

This research aimed to optimize the compressive strength of bio-foamed concrete brick (B-FCB) via a combination of the natural sequestration of CO2 and the bio-reaction of B. tequilensis enzymes. The experiments were guided by two optimization methods, namely, 2k factorial and response surface methodology (RSM). The 2k factorial analysis was carried out to screen the important factors; then, RSM analysis was performed to optimize the compressive strength of B-FCB. Four factors, namely, density (D), B. tequilensis concentration (B), temperature (T), and CO2 concentration, were selectively varied during the study. The optimum compressive strength of B-FCB was 8.22 MPa, as deduced from the following conditions: 10% CO2, 3 × 107 cell/mL of B, 27 °C of T and 1800 kg/m3 of D after 28 days. The use of B. tequilensis in B-FCB improved the compressive strength by 35.5% compared to the foamed concrete brick (FCB) after 28 days. A microstructure analysis by scanning electronic microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction analysis (XRD) reflected the changes in chemical element levels and calcium carbonate (CaCO3) precipitation in the B-FCB pores. This was due to the B. tequilensis surface reactions of carbonic anhydrase (CA) and urease enzyme with calcium in cement and sequestered CO2 during the curing time.

scholarly journals Influencing Factors on the Healing Performance of Microcapsule Self-Healing Concrete

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4139
Author(s):  
Yanju Wang ◽  
Zhiyang Lin ◽  
Can Tang ◽  
Wenfeng Hao
Keyword(s):  
Compressive Strength ◽  
Sodium Silicate ◽  
Recovery Rate ◽  
Sound Speed ◽  
Orthogonal Experimental Design ◽  
Self Healing ◽  
Damage Degree ◽  
Strength Recovery ◽  
Healing System ◽  
Recovery Performance

The amounts of the components in a microcapsule self-healing system significantly impact the basic performance and self-healing performance of concrete. In this paper, an orthogonal experimental design is used to investigate the healing performance of microcapsule self-healing concrete under different pre-damage loads. The strength recovery performance and sound speed recovery performance under extensive damage are analyzed. The optimum factor combination of the microcapsule self-healing concrete is obtained. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) are carried out on the concrete samples before and after healing to determine the healing mechanism. The results show that the healing effect of self-healing concrete decreases with an increase in the pre-damage load, and the sound speed recovery rate increases with an increase in the damage degree. The influence of the sodium silicate content on the compressive strength and compressive strength recovery rate of the self-healing concrete increases, followed by a decrease. The optimum combination of factors of the microcapsule self-healing system is 3% microcapsules, 30% sodium silicate, and 15% sodium fluosilicate. The results can be used for the design and preparation of self-healing concrete.

scholarly journals The Impact of Traffic-Induced Bridge Vibration on Rapid Repairing High-Performance Concrete for Bridge Deck Pavement Repairs

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Wei Wang ◽  
Shuo Liu ◽  
Qizhi Wang ◽  
Wei Yuan ◽  
Mingzhang Chen ◽  
...  
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Bridge Deck ◽  
High Performance Concrete ◽  
Reduction Rate ◽  
Harmonic Vibration ◽  
Hydration Reaction ◽  
Self Healing ◽  
The Impact ◽  
Bridge Deck Pavement

Based on forced vibration tests for high-performance concrete (HPC), the influence of bridge vibration induced by traveling vehicle on compressive strength and durability of HPC has been studied. It is concluded that 1 d and 2 d compressive strength of HPC decreased significantly, and the maximum reduction rate is 9.1%, while 28 d compressive strength of HPC had a slight lower with a 3% maximal drop under the action of two simple harmonic vibrations with 2 Hz, 3 mm amplitude, and 4 Hz, 3 mm amplitude. Moreover, the vibration had a slight effect on the compressive strength of HPC when the simple harmonic vibration had 4 Hz and 1 mm amplitude; it is indicated that the amplitude exerts a more prominent influence on the earlier compressive strength with the comparison of the frequency. In addition, the impact of simple harmonic vibration on durability of HPC can be ignored; this shows the self-healing function of concrete resulting from later hydration reaction. Thus, the research achievements mentioned above can contribute to learning the laws by which bridge vibration affects the properties of concrete and provide technical support for the design and construction of the bridge deck pavement maintenance.

Mechanical responses of microencapsulated self-healing cementitious composites under compressive loading based on a micromechanical damage-healing model

2021 ◽  
pp. 105678952110112
Author(s):  
Kaihang Han ◽  
Jiann-Wen Woody Ju ◽  
Yinghui Zhu ◽  
Hao Zhang ◽  
Tien-Shu Chang ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Compressive Strength ◽  
Micromechanical Model ◽  
Cementitious Composites ◽  
Self Healing ◽  
Damage Degree ◽  
Healing Efficiency ◽  
The Matrix ◽  
Healing Agent ◽  
Damage Healing

The cementitious composites with microencapsulated healing agents have become a class of hotspots in the field of construction materials, and they have very broad application prospects and research values. The in-depth study on multi-scale mechanical behaviors of microencapsulated self-healing cementitious composites is critical to quantitatively account for the mechanical response during the damage-healing process. This paper proposes a three-dimensional evolutionary micromechanical model to quantitatively explain the self-healing effects of microencapsulated healing agents on the damage induced by microcracks. By virtue of the proposed 3 D micromechanical model, the evolutionary domains of microcrack growth (DMG) and corresponding compliances of the initial, extended and repaired phases are obtained. Moreover, the elaborate studies are conducted to inspect the effects of various system parameters involving the healing efficiency, fracture toughness and preloading-induced damage degrees on the compliances and stress-strain relations. The results indicate that relatively significant healing efficiency, preloading-induced damage degree and the fracture toughness of polymerized healing agent with the matrix will lead to a higher compressive strength and stiffness. However, the specimen will break owing to the nucleated microcracks rather than the repaired kinked microcracks. Further, excessive higher values of healing efficiency, preloading-induced damage degree and the fracture toughness of polymerized healing agent with the matrix will not affect the compressive strength of the cementitious composites. Therefore, a stronger matrix is required. To achieve the desired healing effects, the specific parameters of both the matrix and microcapsules should be selected prudently.

Development of Ca2+-based, ion-responsive superabsorbent hydrogel for cement applications: Self-healing and compressive strength

2019 ◽  
Vol 538 ◽  
pp. 397-403 ◽  
Author(s):  
Miaomiao Hu ◽  
Jintang Guo ◽  
Jiangbo Du ◽  
Zhenxing Liu ◽  
Pengpeng Li ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Self Healing ◽  
Superabsorbent Hydrogel

scholarly journals Preliminary research for identification of bacteria useful in microbially induced calcium carbonate precipitation

2018 ◽  
Vol 44 ◽  
pp. 00115
Author(s):  
Katarzyna Misiołek ◽  
Paweł Popielski ◽  
Katarzyna Affek
Keyword(s):  
Calcium Carbonate ◽  
Soil Stabilization ◽  
Carbonate Precipitation ◽  
Calcium Carbonate Precipitation ◽  
Construction Sites ◽  
Calcite Precipitation ◽  
Strength Parameters ◽  
Gram Staining ◽  
Identification Of Bacteria

MICP (Microbially Induced Calcite Precipitation) is a new biological method in soil stabilization. This cheap and eco-friendly technique improves strength parameters of the ground such as shear strength and decreases the permeability of gravelly and sandy soil. There are variety of microorganisms that can be used in calcite precipitation. The most popular method is precipitation of calcium carbonate by bacteria. The main purpose of the article is to present the results from Gram staining of bacteria isolated from construction sites, which is the first step of their identification. Gram’s method allows to find out which morphological groups of bacteria are adapted to conditions present in soil from construction sites and therefore are potentially able to produce calcite. The article describes the methodology of isolation, staining and determination of morphological types of bacteria.

scholarly journals Effect of ultrafine natural steatite powder, super plasticizer and VMA on the fresh and hardened properties of self-compacting cement paste and mortar

2021 ◽  
Author(s):  
S. Christopher Gnanaraj ◽  
Ramesh Babu Chokkalingam ◽  
G. Lizia Thankam ◽  
S.K.M. Pothinathan
Keyword(s):  
Compressive Strength ◽  
Cement Paste ◽  
Water Demand ◽  
Construction Material ◽  
Setting Time ◽  
Mineral Admixture ◽  
Self Healing ◽  
Chemical Admixtures ◽  
Hardened Properties ◽  
Viscosity Modifying Admixture

AbstractFor the past few decades innovation in construction material has grown a lot. This leads to special concrete such as self-compacting concrete, geopolymer concrete, self-healing concrete, etc. To prepare a special concrete apart from regular concreting material some sort of special materials was also needed, like mineral and chemical admixtures. Hence it is necessary to study the effect of these admixtures in cement paste and mortar before studying the same in concrete. Hence an attempt is made to study the effect of mineral and chemical admixtures in the fresh and hardened properties of cement paste and mortar. For this study ultrafine natural steatite powder is taken as mineral admixture and polycarboxylic based superplasticizer and glenium stream 2 were taken as chemical admixtures. Ultrafine natural steatite powder was used as additive to cement in various percentages like 0%, 5%, 10%, 15%, 20% and 25%. Superplasticizer and viscosity modifying admixture were taken as 1.5% and 0.5%, respectively. Then various combinations were worked out. To study the fresh property of cement paste consistency, initial setting time and miniature slump cone test were done based on the results yield stress of cement paste also calculated empirically. To study the hardened property compression test on cement mortar was done. Based on the test results it is clear that the addition of ultrafine natural steatite powder increases the water demand hence reduces the workability. On the other hand, it increases the compressive strength up to a certain limit. Adding superplasticizer increases the workability and reduces the water demand and viscosity modifying admixture reduces the bleeding and segregation effects hence increases the compressive strength.

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