scholarly journals Ureolytic/Non-Ureolytic Bacteria Co-Cultured Self-Healing Agent for Cementitious Materials Crack Repair

Materials ◽  
2018 ◽  
Vol 11 (5) ◽  
pp. 782 ◽  
Author(s):  
Hyeong Son ◽  
Ha Kim ◽  
Sol Park ◽  
Haeng Lee
Keyword(s):  
Cementitious Materials ◽  
Self Healing ◽  
Healing Agent ◽  
Crack Repair ◽  
Ureolytic Bacteria

Research on PA Heat-Melt Adhesive Being Used as Self-Healing Agent in Cementitious Materials

2011 ◽  
Vol 374-377 ◽  
pp. 1899-1903
Author(s):  
Xiong Zhou Yuan ◽  
Wei Sun ◽  
Xiao Bao Zuo
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Chemical Stability ◽  
Bonding Strength ◽  
Research Team ◽  
Cementitious Materials ◽  
Experimental Results ◽  
Self Healing ◽  
Detailed Consideration ◽  
Healing Agent

Based on detailed consideration of the autonomic healing concept of microencapsulated healing agent, micro- bacteria induced calcite and shape memory alloys, our research team proposed a new self-healing technique coupled with of SMA and heat-melt adhesive. In this article, chemical stability and bonding strength with cementitious materials of PA heat-melt adhesive were tested. Experimental results show that PA heat-melt adhesive may contain the ability being used in self-healing techniques coupled with SMA.

scholarly journals Encapsulation Techniques and Test Methods of Evaluating the Bacteria-Based Self-Healing Efficiency of Concrete: A Literature Review

2020 ◽  
Vol 62 (1) ◽  
pp. 63-85
Author(s):  
Rahul Roy ◽  
Emanuele Rossi ◽  
Johan Silfwerbrand ◽  
Henk Jonkers
Keyword(s):  
Service Life ◽  
Polymeric Materials ◽  
Cementitious Materials ◽  
Test Methods ◽  
Self Healing ◽  
Load Factors ◽  
Healing Efficiency ◽  
Healing Agent ◽  
Maximum Crack ◽  
Encapsulated Bacteria

AbstractCrack formation in concrete structures due to various load and non-load factors leading to degradation of service life is very common. Repair and maintenance operations are, therefore, necessary to prevent cracks propagating and reducing the service life of the structures. Accessibility to affected areas can, however, be difficult as the reconstruction and maintenance of concrete buildings are expensive in labour and capital. Autonomous healing by encapsulated bacteria-based self-healing agents is a possible solution. During this process, the bacteria are released from a broken capsule or triggered by water and oxygen access. However, its performance and reliability depend on continuous water supply, protection against the harsh environment, and densification of the cementitious matrix for the bacteria to act. There are vast methods of encapsulating bacteria and the most common carriers used are: encapsulation in polymeric materials, lightweight aggregates, cementitious materials, special minerals, nanomaterials, and waste-derived biomass. Self-healing efficiency of these encapsulated technologies can be assessed through many experimental methodologies according to the literature. These experimental evaluations are performed in terms of quantification of crackhealing, recovery of durability and mechanical properties (macro-level test) and characterization of precipitated crystals by healing agent (micro-level test). Until now, quantification of crack-healing by light microscopy revealed maximum crack width of 1.80mm healed. All research methods available for assesing self-healing efficiency of bacteria-based healing agents are worth reviewing in order to include a coherent, if not standardized framework testing system and a comparative evaluation for a novel incorporated bacteria-based healing agent.

scholarly journals Biological Self-Healing of Cement Paste and Mortar by Non-Ureolytic Bacteria Encapsulated in Alginate Hydrogel Capsules

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3711
Author(s):  
Mohammad Fahimizadeh ◽  
Ayesha Diane Abeyratne ◽  
Lee Sui Mae ◽  
R. K. Raman Singh ◽  
Pooria Pasbakhsh
Keyword(s):  
Cement Paste ◽  
Healing Process ◽  
Cementitious Materials ◽  
The Self ◽  
Self Healing ◽  
Alkaline Conditions ◽  
Healing Agent ◽  
Encapsulated Bacteria ◽  
The Right

Crack formation in concrete is one of the main reasons for concrete degradation. Calcium alginate capsules containing biological self-healing agents for cementitious materials were studied for the self-healing of cement paste and mortars through in vitro characterizations such as healing agent survivability and retention, material stability, and biomineralization, followed by in situ self-healing observation in pre-cracked cement paste and mortar specimens. Our results showed that bacterial spores fully survived the encapsulation process and would not leach out during cement mixing. Encapsulated bacteria precipitated CaCO3 when exposed to water, oxygen, and calcium under alkaline conditions by releasing CO32− ions into the cement environment. Capsule rupture is not required for the initiation of the healing process, but exposure to the right conditions are. After 56 days of wet–dry cycles, the capsules resulted in flexural strength regain as high as 39.6% for the cement mortar and 32.5% for the cement paste specimens. Full crack closure was observed at 28 days for cement mortars with the healing agents. The self-healing system acted as a biological CO32− pump that can keep the bio-agents retained, protected, and active for up to 56 days of wet-dry incubation. This promising self-healing strategy requires further research and optimization.

Self-healing efficiency of cementitious materials containing tubular capsules filled with healing agent

2011 ◽  
Vol 33 (4) ◽  
pp. 497-505 ◽  
Author(s):  
Kim Van Tittelboom ◽  
Nele De Belie ◽  
Denis Van Loo ◽  
Patric Jacobs
Keyword(s):  
Cementitious Materials ◽  
Self Healing ◽  
Healing Efficiency ◽  
Healing Agent

scholarly journals Comparison of Microbially Induced Healing Solutions for Crack Repairs of Cement-Based Infrastructure

2021 ◽  
Vol 13 (8) ◽  
pp. 4287
Author(s):  
John Milan van der Bergh ◽  
Bojan Miljević ◽  
Snežana Vučetić ◽  
Olja Šovljanski ◽  
Siniša Markov ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Service Life ◽  
Cementitious Materials ◽  
Bacterial Suspension ◽  
Self Healing ◽  
Construction Costs ◽  
Recovery Processes ◽  
Concrete Crack ◽  
Crack Repair ◽  
Water Absorption Test

Reinforced concrete crack repair and maintenance costs are around 84% to 125% higher than construction costs, which emphasises the need to increase the infrastructure service life. Prolongation of the designed service life of concrete structures can have significant economic and ecological benefits by minimising the maintenance actions and related increase of carbon and energy expenditure, making it more sustainable. Different mechanisms such as diffusion, permeation and capillary action are responsible for the transport of fluids inside the concrete, which can impact on the structure service life. This paper presents data on microbially induced repair and self-healing solutions for cementitious materials available in the contemporary literature and compares results of compressive strength test and capillary water absorption test, which are relevant to their sealing and mechanical characteristics. The results of the repair and self-healing solutions (relative to unassisted recovery processes) were “normalized.” Externally applied bacteria-based solutions can improve the compressive strength of cementitious materials from 13% to 27%. The internal solution based solely on bacterial suspension had 19% improvement efficacy. Results also show that “hybrid” solutions, based on both bio-based and non-bio-based components, whether externally or internally applied, have the potential for best repair results, synergistically combining their benefits.

Study of Feasibility of Heat Melt Adhesive Being Used in Crack Self-Healing of Cement-Based Materials

2011 ◽  
Vol 99-100 ◽  
pp. 1087-1091 ◽  
Author(s):  
Xiong Zhou Yuan ◽  
Wei Sun ◽  
Xiao Bao Zuo
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Chemical Stability ◽  
Bonding Strength ◽  
Research Team ◽  
Cementitious Materials ◽  
Self Healing ◽  
Detailed Consideration ◽  
Cement Based Materials ◽  
Healing Agent

Based on detailed consideration of the autonomic healing concept of microencapsulated healing agent, micro- bacteria induced calcite and shape memory alloys, our research team proposed a new self-healing technique coupled with of SMA and heat-melt adhesive. In this article, chemical stability and bonding strength with cementitious materials of EVA heat-melt adhesive were tested. Experimental results show that EVA heat-melt adhesive may contain the ability being used in self-healing techniques coupled with SMA.

scholarly journals Preparation and Characterization of Microcrystalline Wax/Epoxy Resin Microcapsules for Self-Healing of Cementitious Materials

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1725
Author(s):  
Wei Du ◽  
Quantao Liu ◽  
Runsheng Lin ◽  
Xin Su
Keyword(s):  
Epoxy Resin ◽  
Size Distribution ◽  
Weight Ratio ◽  
Cementitious Materials ◽  
Self Healing ◽  
Surface Cracks ◽  
Preparation Temperature ◽  
Core Content ◽  
Healing Agent

Self-healing of cracks in cementitious materials using healing agents encapsulated in microcapsules is an intelligent and effective method. In this study, microcapsules were prepared by the melt–dispersion–condensation method using microcrystalline wax as the shell and E-51 epoxy resin as the healing agent. The effects of preparation process parameters and microcrystalline wax/E-51 epoxy resin weight ratio on the core content, particle size distribution, thermal properties, morphology, and chemical composition of microcapsules were investigated. The results indicated that the optimal parameters of the microcapsule were microcrystalline wax/E-51 epoxy resin weight ratio of 1:1.2, stirring speed of 900 rpm, and preparation temperature of 105 °C. The effects of microcapsules on pore size distribution, pore structure, mechanical properties, permeability, and ultrasonic amplitude of mortar were determined, and the self-healing ability of mortar with different contents of microcapsules was evaluated. The optimal content of microcapsules in mortars was 4% of the cement weight, and the surface cracks of mortar containing microcapsules with an initial width of 0.28 mm were self-healed within three days, indicating that microcapsules have excellent self-healing ability for cementitious materials.

Methyl methacrylate as a healing agent for self-healing cementitious materials

2011 ◽  
Vol 20 (12) ◽  
pp. 125016 ◽  
Author(s):  
K Van Tittelboom ◽  
K Adesanya ◽  
P Dubruel ◽  
P Van Puyvelde ◽  
N De Belie
Keyword(s):  
Methyl Methacrylate ◽  
Cementitious Materials ◽  
Self Healing ◽  
Healing Agent

scholarly journals Screening of native ureolytic bacteria for self-healing in cementitious materials

2020 ◽  
Vol 849 ◽  
pp. 012074
Author(s):  
Hassan Amer Algaifi ◽  
Abdul Rahman Mohd Sam ◽  
Suhaimi Abu Bakar ◽  
Ahmad Razin Zainal Abidin ◽  
Shafinaz Shahir
Keyword(s):  
Cementitious Materials ◽  
Self Healing ◽  
Ureolytic Bacteria

Microscopic Tests on Evaluation of Self-Healing Efficiency in Cementitious Materials with a Novel Self-Healing System

2020 ◽  
Vol 996 ◽  
pp. 104-109 ◽  
Author(s):  
Zhen Hong Yang ◽  
Xian Feng Wang ◽  
Ning Xu Han ◽  
Feng Xing
Keyword(s):  
Joint Action ◽  
Cementitious Materials ◽  
Cementitious Material ◽  
Self Healing ◽  
Test Results ◽  
Expansive Agent ◽  
Healing System ◽  
Healing Efficiency ◽  
Healing Agent

In this study, Na2CO3 solution as a self-healing agent was impregnated in LWA for autonomic self-healing on cracked cementitious material. The results showed that under the joint action of expansive agent, crystalline additive, phosphate and carbonate, the crack area showed a high self-healing efficiency (close to 70%) after curing in the still water 28d. SEM-EDS test results showed that in addition to ettringite and C-S-H/C-A-S-H, there was also a large amount of CaCO3 crystal in the depths of the crack.

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