Curing is a mandatory process in concrete construction to ensure that concrete achieves its specified strength, durability, and service life. In accordance with AS 3600 – Concrete Structures, adequate curing must be provided to prevent premature moisture loss and to allow continued hydration of cement.
Curing of concrete slabs by hessian cloth (jute fabric) is a well-established and compliant method widely used across Australian construction projects, particularly in hot, dry, or windy conditions.
Hessian cloth is a natural, woven jute fabric with high water absorption capacity. When used for curing, it acts as a moisture-retaining medium that maintains a damp environment at the concrete surface.
Hessian cloth used for curing shall be:
< Clean and free from oil, grease, or contaminants
< Untreated and suitable for continuous wetting
< Capable of remaining in full contact with the concrete surface
Principle of Hessian Curing
Concrete strength development occurs through hydration of cement, which requires sufficient moisture and time. AS 3600 emphasizes that curing shall minimize moisture loss from the concrete surface during the early age period.
Hessian curing achieves this by:
< Reducing evaporation due to sun and wind
< Maintaining uniform surface moisture
< Preventing plastic and drying shrinkage cracking
Method of Curing Concrete Slab by Hessian Cloth
Commencement of Curing
Curing shall commence as soon as the concrete surface has hardened sufficiently to prevent damage and after surface bleed water has dissipated. Early commencement is critical to comply with AS 3600 curing requirements.
Placement of Hessian
Clean hessian cloth shall be laid evenly over the entire slab surface. Adjacent sheets shall overlap by a minimum of 75–100 mm to ensure full coverage and prevent exposed areas.
Wetting Procedure
The hessian shall be thoroughly saturated using clean potable water. The cloth must remain in direct contact with the concrete surface at all times.
Maintenance of Moisture
Hessian cloth shall be kept continuously damp throughout the curing period. Water shall be applied at regular intervals, typically 2 to 4 times per day, or more frequently under hot, windy, or low-humidity conditions.
The hessian must not be permitted to dry out at any stage.
Duration of Curing
Unless otherwise specified in project documentation, the minimum curing periods shall be:
< 7 days for normal-class concrete using General Purpose (GP) cement
< 10–14 days for blended cements or higher-strength concrete
< Longer curing periods where specified by the engineer or exposure classification under AS 3600
Advantages of Hessian Cloth Curing
< Complies with wet curing methods permitted under AS 3600
< Provides effective moisture retention and uniform hydration
< Reduces surface cracking, dusting, and curling
< Improves compressive strength and surface durability
< Environmentally sustainable and biodegradable
< Reusable and cost-effective for site operations
Recommended Hessian Specifications (Typical Australian Practice)
< Material: 100% natural jute (hessian)
< Mass: 250–400 GSM (305 GSM is widely use worldwide)
< Width: 1.5 m to 3.58m (3.58m width x 25m Length is widely use worldwide)
< Weight: 18oz
< Condition: Untreated, oil-free, and clean
Precautions and Quality Control
< Hessian shall not be allowed to dry during the curing period
< Care shall be taken when placing and removing hessian to avoid surface damage
< Contaminated or stained hessian shall not be used
< Curing activities shall be recorded as part of site QA documentation where required
Curing of concrete slabs by hessian cloth is a compliant, effective, and widely accepted curing method under Australian Standards. When applied and maintained correctly, hessian curing ensures adequate hydration, reduces early-age cracking, and enhances the long-term performance and durability of concrete slabs. It remains a preferred solution for many Australian construction projects due to its reliability, sustainability, and cost efficiency.
Axon Corporation Pty Ltd — a leading supplier of sustainable hessian and jute products including heavy-duty hessian cloth rolls suitable for curing and other industrial uses.
Contact details:
📞 Phone: +61 481 952 886 (Australian mobile)
📧 Email: ceo@axoncorporation.com.au
🌐 Website: www.axoncorporation.com.au
🏢 Address: 11 Nevada Ct, Hoppers Crossing VIC 3029, Australia
