So, what is the curing? Simply put, it is the process of keeping concrete moist while maintaining the correct temperature. Or

Curing is the process of maintaining the correct moisture content in concrete after placement, allowing proper hydration of the cement. This chemical reaction between cement and water turns concrete into a strong and durable material. So, proper curing isn’t just a step – it’s the secret sauce to strength, durability, and crack resistance in your concrete projects.

Why is it important? Well, especially when the water-to-cement ratio is low or when our mix contains materials like slag or ash, it is important to prevent moisture loss.

Now, let’s break it down. If the water-cement ratio is low or we have additives like slag, the curing process becomes extra important. Why? Because it helps prevent the concrete from drying out too quickly. And believe me, this is not what we want!

For those using super sulphated cement, which is great for some projects, there is a problem. The rate of strengthening of concrete slows down at low temperatures. To ensure that it is in the best shape, proper treatment is necessary. Keep those surfaces moist for at least seven days,

Let’s explore some essential or common abbreviations used in the text above. Together, let’s try to understand them

Definition 1. Water cement -Ratio (W/C-ratio)

The water-cement ratio, represented as the W/C ratio, is the ratio of the weight of water to the weight of cement in the concrete mix. This important factor has a significant impact on the strength and durability of concrete. A lower w/c ratio contributes to stronger and more durable concrete, making it an important consideration in mix design.

You will Like The Topics

What is Cement and Its Types|Decoding Cement And Its Varieties|
What is Concrete? Concrete History | Advanced technology | OCT – 023
Concrete manufacturing process
Workability of concrete : Basic understanding and importance
Factor affecting on the workability of concrete
Workability tests; Slump test; workability of concrete
Tests; Compaction factor test.

Definition 2. Hydration of cement.

Hydration of cement involves the chemical reaction between cement and water, which is necessary for the cement to harden. This reaction generates heat and forms various hydration products, of which calcium silicate hydrate (C–S–H) is the primary strength-contributing phase in concrete. Hydration is an important process to develop the strength and other desirable properties of concrete.

Definition 3. Slag and fly ash.

“Slag” and “Fly ash” refer to supplementary cementitious materials (SCM) added to the concrete mix. “Slag” may indicate ground granulated blast-furnace slag (GGBFS), and “ash” may refer to fly ash or other pozzolanic material. These additives enhance concrete properties and stability.

Definition 4. Ground Granulated Blast Furnace Slag (GGBFS)

Ground Granulated Blast Furnace Slag (GGBFS) is obtained by grinding granular blast furnace slag conforming to IS 12089. It can be used as a partial replacement for ordinary Portland cement, ensuring uniform mixing with the cement.

Definition 5. Super sulphated cement.

Super sulphated cement is prepared from finely ground blast furnace slag (80–85%), calcium sulphate (10–15%), and Portland cement (1–2%). In this cement, C3A, which is sensitive to sulphate, is limited to less than 3.5%.

What are the methods of curing of concrete

1. Water curing
2. Plastic sheeting
3. Curing Compound
4. Steam curing
5. Membrane Curing

1.    Water curing: a traditional Method.

Water curing stands out as a straightforward and widely used method in the array of concrete curing techniques. It involves keeping the concrete surface consistently wet for the entire curing period, typically around 7 days. This method is especially effective for small projects, surfaces, or uncomplicated structures. Let’s dive into the basics and steps of water curing:

Basic Steps of water curing or curing of concrete:

1.      Preparation:

• Remove excess water from the concrete surface to avoid ponding issues.
• Ensure a clean surface, free from debris.

2.      Ponding:

• Construct temporary berms around the concrete structure, forming a shallow pool.
• Fill the pool with water to a depth of at least 1 inch (25 mm).
• Maintain the water level throughout the curing period.

3.      Water Spraying:

• Use a hose or sprinkler for continuous water spraying on the concrete surface.
• Ensure even wetting of the entire surface.
• Spray at least 4–5 times daily, more frequently in hot or windy conditions.

4.      Soaking:

• Immerse the concrete element directly in water.
• Ensure the entire element is submerged.
• Maintain the water level throughout the curing period.

Monitoring of Water curing;

• Regularly check the moisture content of the concrete surface.
• If the surface appears dry or dusty, resume water curing immediately.
• Protect the concrete from direct sunlight, rain, and strong winds.

Additional Tips:

• Start water curing as soon as possible after placing and finishing the concrete.
• Avoid excessive bleeding of water to the surface, as it can weaken the concrete.
• Use clean water for curing to prevent contamination.
• Remember, proper curing is essential for concrete to achieve its full strength, durability, and resistance to cracking.

Here is some additional method for curing of concrete

2.      Plastic Sheeting: a highly effective method.

Plastic sheeting emerges as a highly effective method for curing concrete, especially on slabs and horizontal surfaces. This technique involves covering the concrete surface with a layer of plastic sheeting to prevent moisture loss. The simplicity of application and removal, coupled with its effectiveness in retaining moisture, makes plastic sheeting suitable for various concrete types.

Advantages:

• Easy to apply and remove.
• Effective in retaining moisture.
• Suitable for a variety of concrete types.

Disadvantages:

• May trap heat, causing accelerated hydration in hot weather.
• May not be as effective in windy conditions.

3.    Curing Compounds.

Curing compounds, liquid film-forming materials, offer a convenient solution for concrete curing. Applied to the concrete surfaces, these compounds form a temporary seal that prevents moisture loss, facilitating proper hydration of cement. Quick and easy to apply, curing compounds are effective across various concrete types.

Advantages:

• Quick and easy application.
• Effective in preventing moisture loss.
• Suitable for various concrete types.

Disadvantages:

• Can be more expensive.
• May require removal after curing.

You will Like The Topics

What is Cement and Its Types|Decoding Cement And Its Varieties|
What is Concrete? Concrete History | Advanced technology | OCT – 023
Concrete manufacturing process
Workability of concrete : Basic understanding and importance
Factor affecting on the workability of concrete
Workability tests; Slump test; workability of concrete
Tests; Compaction factor test.

Follow Us on youtube

Steam Curing: Fast-Track Strength Development

Steam curing is an accelerated method commonly employed for precast concrete products. This technique exposes the concrete to steam at elevated temperatures and pressures, resulting in rapid strength development and reduced curing time.

Advantages:

• Rapid strength development.
• Reduced curing time.
• Suitable for precast concrete.

Disadvantages:

• Requires specialized equipment.
• Can be expensive.
• Not suitable for all types of concrete.

Membrane Curing: Thin Layers of Protection

In membrane curing, a thin layer of wax or resin is applied to concrete surfaces to form a seal, preventing moisture loss and allowing proper hydration of cement. This method shares advantages with easy application and removal, effectiveness in retaining moisture, and suitability for various concrete types.

Advantages:

• Easy to apply and remove.
• Effective in retaining moisture.
• Suitable for a variety of concrete types.

Disadvantages:

• Can be expensive.
• May not be as effective as other methods.

Why curing of concrete is Important

Strength Development: Proper curing ensures optimum cement hydration, allowing the concrete to reach 70% of its final strength within 28 days.

Enhanced Durability: Produces denser, less porous concrete that is resistant to weather, abrasion and chemicals, reducing surface defects.

Reduction in Cracks: Reduces shrinkage, reducing the risk of cracks that compromise structure and aesthetics.

Consequences of improper treatment:

Loss of strength: Inadequate curing limits the strength of concrete, making it prone to damage.

Increased Cracking: Excessive shrinkage from improper curing compromises integrity and appearance.

Decreased durability: Concrete becomes more sensitive to weathering, abrasion and chemical attack, shortening its lifespan.

Ensuring proper treatment (as per IS code guidelines)

• Early Start: Begin curing immediately after concrete is placed.
• Moisture Maintenance: Keep concrete surfaces constantly moist during the curing period.
• Protection against extreme conditions: Prevent concrete from freezing and rapid drying.
• Monitoring: Assess the moisture level of concrete regularly to ensure compliance with IS codes.

Curing Duration Table As per the IS codes, Guidelines/ Standard,

Concrete Type	Minimum Curing Period	Recommended Curing Period (Severe Conditions)
Normal-weight concrete	7 days	10-14 days
Concrete with mineral admixtures or blended cements	10 days	14-21 days
High-strength concrete	14 days	21-28 days
Concrete exposed to freezing temperatures	14 days	21-28 days
Concrete exposed to high sulphate concentrations	14 days	21-28 days