Self Healing Concrete: The Future of Dureble Structure

Abstract

Concrete is the most common building material in the world, but it has one big weakness: it cracks easily. These cracks may look small at first, but over time they allow water, chemicals, and air to enter, which reduces strength and durability. Normally, repairing cracks takes time, money, and effort, and repeated maintenance is not sustainable. To solve this problem, researchers have developed self-healing concrete—a type of concrete that can repair its own cracks without human help. This paper reviews the different methods, benefits, challenges, and future possibilities of self-healing concrete. There are two main ways self-healing works. The first is natural (autogenous) healing, where tiny cracks close by themselves due to leftover cement reacting with water or due to natural chemical processes. However, this only works for very small cracks. The second method is engineered (autonomic) healing, where scientists add special agents into the concrete. These may include bacteria that produce calcium carbonate, tiny capsules filled with glue-like or mineral materials, or tiny hollow tubes (vascular systems) that release healing agents when cracks appear. Among these, the bacterial method is very promising because it is eco-friendly and can heal wider cracks, though capsules and vascular systems also show good results in controlled conditions. How well self-healing concrete works depends on factors such as the width of cracks, the surrounding environment (humidity, temperature, and exposure to chemicals), and the type and amount of healing agents used. Modern testing methods, such as advanced imaging and permeability checks, help scientists measure the healing ability more accurately. New approaches, like nanotechnology and engineered bacteria, are making healing more reliable and effective. The biggest advantage of self-healing concrete is that it makes structures last longer, need fewer repairs, and reduce maintenance costs. This also supports sustainability because it reduces waste, energy use, and carbon emissions linked to repairing or rebuilding structures. In short, it is a step toward greener and longer-lasting infrastructure. At the same time, there are challenges. Self-healing concrete is still more expensive than normal concrete. There are doubts about how it will perform over many decades in real-life conditions, and large cracks remain difficult to heal completely. Also, there is no global standard yet for testing or measuring its healing power. More research, field trials, and collaboration between engineers, scientists, and industry are needed to make this material practical for everyday construction.

Introduction

Concrete is widely used in construction due to its strength and affordability, but it has a major flaw—it cracks. These cracks can let in water and harmful chemicals, weakening the material and reducing the structure’s lifespan. Traditional repair methods are costly, repetitive, and environmentally taxing.

Self-healing concrete offers a smart and sustainable solution by repairing its own cracks without human intervention. Inspired by biological healing, this technology aims to reduce maintenance costs, extend structure lifespans, and minimize environmental impact.

There are two main types of self-healing:

1. Natural (autogenous) healing – uses leftover cement or mineral deposits to seal small cracks (under 0.3 mm), especially in wet environments.

2. Engineered (autonomic) healing – uses added materials like:

   • Bacteria that produce limestone when exposed to water.

   • Capsules that release sealants when cracks occur.

   • Vascular systems that channel healing agents through small tubes.

   • Smart additives like expanding materials or minerals (e.g., fly ash) that enhance healing.

Literature Review Highlights:

• Bacterial concrete can heal cracks up to 0.8 mm and restore 80–90% strength, but cost and bacteria lifespan are concerns.

• Encapsulation methods restore up to 75% strength, though capsules may break during mixing.

• Natural healing is low-cost but limited to tiny cracks in moist environments.

• Mineral additives like fly ash improve healing and chemical resistance.

• Real-life testing in a reservoir showed 90% leakage reduction in 6 months.

• Hybrid methods combining multiple techniques showed better performance, even in wet-dry conditions.

Testing Methods Include:

• Monitoring water leakage

• Measuring strength recovery

• Microscopic crack inspection

• Durability testing under harsh conditions

Challenges:

• High initial cost

• Limited data on long-term real-world performance

• Lack of standardized testing methods

Conclusion

Concrete is the most widely used material for construction, but its biggest problem is that it cracks. These cracks allow water and chemicals to enter, which slowly damage the concrete and the steel inside. Normally, fixing these cracks requires repairs that are expensive, time-consuming, and harmful to the environment because they use a lot of materials and energy. This is where self-healing concrete comes in. It offers a new and smarter way to make structures stronger and longer lasting by letting concrete repair itself. Self-healing concrete works in two main ways. The first is natural healing, where tiny cracks close on their own because of chemical reactions that already exist in concrete. This happens only for very small cracks and under the right conditions. The second way is engineered healing, where scientists add special materials to help concrete repair larger cracks. This includes using bacteria that produce limestone, capsules filled with glue-like liquids, or tiny tubes that release healing agents when cracks form. These methods make concrete much more durable than ordinary concrete. The benefits are clear. Self-healing concrete reduces the need for frequent repairs, saves money over the life of a structure, and is better for the environment because it cuts down on waste and carbon emissions. It can also make important structures like bridges, tunnels, and dams safer and longer lasting, which is essential as infrastructure around the world continues to age. At the same time, there are challenges. Right now, self-healing concrete is more expensive than normal concrete. There are also questions about how well it will work in real-world conditions over decades, not just in laboratory tests. Another problem is that there are no standard tests to measure how well it heals, which makes it harder for industries to adopt it. Also, there have been only a few large-scale projects so far, so more real-world applications are needed. Looking to the future, researchers are working to make self-healing concrete cheaper and more reliable. New technologies, like nanomaterials and smart additives, may improve its performance. At the same time, cooperation between scientists, engineers, and industries is needed to create testing standards and bring this material into mainstream construction. In simple terms, self-healing concrete has the potential to change how we build. Instead of relying on constant repairs, we could have structures that take care of themselves, just like living organisms do. While there are still hurdles to overcome, this technology could make construction more sustainable, cost-effective, and resilient, helping us build stronger and smarter infrastructure for the future.

References

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Copyright

Copyright © 2025 Prof. Shahrukh Kureshi, Kiran Kumbhare, Ayush Guntiwar, Rohit Duble, Aditya Mahakalkar. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.