Concrete curing is one of the most crucial stages in construction, determining the durability, load-bearing capacity, and lifespan of a structure. If not cured properly, concrete can crack, weaken in quality, and compromise the overall integrity of the structure.
So, what is the correct process for curing concrete? Let’s explore the details in this article!
Why Is Concrete Curing Necessary?
After pouring, concrete undergoes a setting and strengthening process. During this phase, if the concrete loses moisture too quickly, shrinkage and cracking will occur, weakening the structure.
Proper concrete curing helps to:
- Ensure the concrete reaches its maximum strength.
- Prevent cracks and surface shrinkage.
- Maintain durability and extend the structure’s lifespan.
- Optimize structural quality and load-bearing performance.
Therefore, curing must be carried out immediately after pouring and continue for a sufficient period to allow the concrete to develop the best possible strength.
Effective Concrete Curing Methods
1. Keeping Formwork in Place After Pouring
One simple yet effective method is to avoid removing the formwork immediately. Formwork helps retain natural moisture and reduces excessive water evaporation.
Tip: You can spray water directly on the formwork to increase moisture levels and cool the concrete surface.
2. Regularly Watering the Concrete
Watering the concrete prevents rapid moisture loss, ensuring a complete hydration process for the cement.
Standard Watering Schedule:
- First week:
- Daytime: Water every 3 hours.
- Nighttime: At least once.
- From day 14 to day 18:
- Maintain watering at least 3 times per day.
Important Notes:
- Use a fine mist spray instead of pouring large amounts of water unevenly.
- If it rains right after pouring, cover the concrete immediately to prevent surface defects.
3. Cement Water Curing for Floor and Roof Slabs
When pouring concrete on flat surfaces like floors or roofs, you can:
- Build a small brick barrier to retain cement water.
- After 1 hour, stir the cement water to prevent heavy cement particles from settling.
Precautions for Walking on Fresh Concrete:
- Summer: After 1.5 days.
- Winter: After 3 days.
For the first 3 days, avoid walking or placing heavy materials on newly poured concrete.
4. Using Moisture-Retaining Covers for Concrete
To reduce moisture loss, cover the concrete surface with materials that help retain water, such as:
- Natural covers: Fine sand, sawdust, straw, or water hyacinth.
- Synthetic covers: Cement paper, polyethylene sheets, or damp burlap sacks.
Covering Guidelines:
- Ensure the entire concrete surface, including beam edges, is covered.
- Regularly spray water on the covers to maintain moisture.
- In hot weather, use a thick layer of straw to provide both sun protection and moisture retention.
When Should Formwork Be Removed?
Formwork should only be removed when the concrete has reached sufficient load-bearing strength.
Standard removal time: After 3–4 weeks if the temperature ranges between 20°C – 30°C.
Warnings:
- Removing formwork too early can cause structural collapse, posing serious safety risks.
- After removing the formwork, the concrete can only bear its own weight (static load), not additional loads (live loads such as people or furniture).
- If early removal is unavoidable, additional supports must be installed for critical elements like slabs and beams.
Key Considerations for Concrete Curing
- Do not let concrete lose moisture too quickly, especially in the first 3 days.
- Avoid walking or placing heavy objects on freshly poured concrete.
- Cover the concrete immediately if it rains after pouring.
- Continue watering for 7–14 days consistently.
- Extend curing time in hot weather conditions.
Conclusion
Proper concrete curing is essential to achieving optimal construction quality, ensuring durability, and maintaining structural stability over time.
Key Takeaways:
- Keep formwork in place and water regularly.
- Use cement water curing when necessary.
- Apply moisture-retaining covers in dry or hot conditions.
- Only remove formwork when the concrete has reached sufficient strength.
Following the correct curing techniques not only ensures stronger, more durable concrete but also enhances the long-term safety of the structure throughout its lifespan.
