Crack Detection and Auto Healing of Reinforced Concrete Beam

Abstract

This invention relates to a novel system for crack detection and auto-healing of reinforced concrete beams, aimed at enhancing structural durability and reducing maintenance costs. The system utilizes advanced sensor technology integrated into the concrete structure to monitor and detect cracks at an early stage. Upon detection, an innovative auto-healing mechanism is activated, which incorporates self-healing materials such as bacterial concrete or microcapsules containing healing agents. These materials respond to crack formation by precipitating calcium carbonate or releasing bonding agents that restore the structural integrity of the concrete. The invention also includes the use of smart adhesives and durable tubes to house and release the healing agents precisely at the damaged locations. This approach increases the lifespan of reinforced concrete structures, minimizes repair frequency, and ensures sustainability by reducing material wastage. The invention is versatile, allowing it to be applied across various infrastructure projects, including bridges, buildings, and marine structures.

Specification

Description:FIELD OF INVENTION
[001] The present invention relates to the field of civil engineering, specifically to the construction and maintenance of reinforced concrete structures. More particularly, it pertains to systems and methods for detecting cracks in reinforced concrete beams and automatically initiating self-healing processes to restore structural integrity and extend the lifespan of such structures.
BACKGROUND AND PRIOR ART
[002] Reinforced concrete is widely used in modern construction due to its high strength and durability. However, over time, concrete structures develop cracks due to various factors such as environmental exposure, load stress, and material fatigue. If not detected and repaired in a timely manner, these cracks can compromise the structural integrity of the concrete, leading to costly maintenance and potential failure of the structure. Traditional methods for crack detection rely on manual inspection or basic sensor technologies, both of which can be inefficient, slow, and prone to human error.
[003] Furthermore, current repair techniques often require costly interventions, including the application of external reinforcements or the use of sealants, which only provide temporary fixes. Recent advancements have explored the potential of self-healing concrete, particularly using biological agents like bacteria, but these solutions lack integration with automated detection systems and are limited by their ability to address only specific types or sizes of cracks.
[004] Therefore, there remains a need for a more efficient, accurate, and automated method to detect cracks early in reinforced concrete structures and trigger a self-healing response to restore integrity without external intervention. This invention aims to overcome these limitations, providing a more robust and sustainable solution to prolong the life of concrete structures.
SUMMARY OF THE INVENTION
[005] The present invention provides a novel approach for enhancing the compressive strength and durability of reinforced concrete beams through automated crack detection and self-healing mechanisms. This invention leverages bacterial concrete as well as glass and acrylic tubes embedded with cyanoacrylate adhesive to address the shortcomings of conventional concrete repair methods.
[006] The bacterial concrete component employs microbiologically induced calcite precipitation (MICP) to enhance the healing process. Results have demonstrated that after cracks have healed, bacterial concrete exhibits significant improvements in compressive strength, increasing by up to 12% and 11% at 7 and 28 days, respectively, when compared to conventional concrete. Additionally, the load-carrying capacity of bacterial concrete shows substantial improvement, making it a superior material for structural applications.
[007] The invention also includes the use of embedded glass and acrylic tubes filled with cyanoacrylate adhesive as an alternative self-healing mechanism. In this system, the cyanoacrylate adhesive is released upon crack formation, aiding in the restoration of structural integrity. Glass tube-embedded concrete filled with cyanoacrylate adhesive showed compressive strength increases of 5% and 1% at 7 and 28 days, respectively, compared to control concrete, while acrylic tube-embedded concrete filled with cyanoacrylate adhesive showed an increase of 3% and 1% over the same time periods.
[008] While cyanoacrylate adhesive provides some improvement in crack healing, the results indicate that bacterial concrete outperforms both glass and acrylic tube systems in terms of compressive strength and overall performance. The glass tube system showed better results compared to the acrylic tube system, but neither was as effective as bacterial concrete in enhancing the structural properties of reinforced concrete beams.
[009] This invention offers an advanced solution for improving the durability and longevity of concrete structures, with bacterial concrete emerging as the most promising method for self-healing, while glass tube systems provide an effective alternative for specific applications. The combination of early crack detection and self-healing mechanisms significantly reduces maintenance costs, extends the service life of concrete structures, and promotes sustainable construction practices.
BRIEF DESCRIPTIONS OF DRAWINGS
[010] Flowchart illustrates the systematic approach for selecting and testing materials in construction, focusing on reinforced concrete (RC) structures. It begins with Material Selection, branching into two main processes: Basic Material Testing and Selection of Auto-Healing Agents and Adhesives. Basic Material Testing includes tests for Cement (fineness and strength), Aggregate (crushing and impact), and Steel (tensile, compression, and bending). Simultaneously, the selection of auto-healing agents covers NDT Method (UPV Test), Auto-Healing Agent (E. Coli bacteria), and Adhesives Embedded in Tubes (cyanoacrylate-based copolymer). Following these tests and selections, the process converges to Mix Design, progressing to Casting and Curing of the RC Beam, testing on the RC Beam, and culminating in Analysis of Results Obtained. This flowchart provides a clear, step-by-step visualization of material evaluation and preparation for constructing durable, self-healing RC structures. , C , Claims:[011] 1. A method for enhancing the compressive strength of reinforced concrete beams after crack healing, comprising:
(a) Integrating bacterial agents into the concrete mix that promote self-healing of cracks, wherein the bacterial agents are effective in increasing the compressive strength of the concrete by at least 12% at 7 days and 11% at 28 days compared to conventional concrete;
(b) Embedding glass tubes filled with cyanoacrylate adhesive within the concrete to facilitate crack healing, wherein the glass tubes contribute to a compressive strength increase of up to 5% at 7 days and 1% at 28 days compared to control concrete;
(c) Embedding acrylic tubes filled with cyanoacrylate adhesive within the concrete to facilitate crack healing, wherein the acrylic tubes contribute to a compressive strength increase of up to 3% at 7 days and 1% at 21 days compared to control concrete.
[012] 2. A reinforced concrete beam with enhanced crack healing properties, comprising:
(a) A concrete matrix incorporating bacterial agents capable of increasing the compressive strength by 12% at 7 days and 11% at 28 days after healing cracks;
(b) Glass tubes embedded within the concrete matrix, filled with cyanoacrylate adhesive, providing up to 5% increase in compressive strength at 7 days and 1% at 28 days compared to conventional concrete;
(c) Acrylic tubes embedded within the concrete matrix, filled with cyanoacrylate adhesive, providing up to 3% increase in compressive strength at 7 days and 1% at 21 days compared to conventional concrete.
[013] 3. The method of claim 1, wherein the bacterial agents are selected from the group consisting of Bacillus species and Serratia species.
[014] 4. The reinforced concrete beam of claim 2, wherein the glass tubes are configured to be spaced evenly throughout the concrete matrix to maximize healing efficiency.
[015] 5. The method of claim 1, wherein the cyanoacrylate adhesive is applied to the tubes in an amount sufficient to enhance crack healing without significantly increasing the overall weight of the concrete beam.
[016] 6. The reinforced concrete beam of claim 2, wherein the acrylic tubes are arranged in a pattern that optimizes the distribution of the cyanoacrylate adhesive for crack repair.
[017] 7. The method of claim 1, wherein the compressive strength increase is measured using standard concrete testing protocols and compared to a control concrete sample with no bacterial agents or embedded tubes.

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