Rapid Set Bags 20kg 25MPa are a convenient fast-setting concrete option for post holes, fence posts, clothes lines, letter boxes, garden projects, and general outdoor fixing jobs where quick hardening is required. Supplied as a ready-to-use dry blend, this rapid set mix only requires clean water on site, making it a practical choice for residential landscaping, fencing, and retaining wall preparation work.
With a fully cured compressive strength of 25MPa, this 20kg rapid set bag is suitable for a wide range of non-structural home, garden, and landscape applications. It is commonly used when setting posts because it hardens quickly, helps reduce waiting time on site, and avoids the need for separate cement, sand, and aggregate mixing.
Rapid set concrete is designed to simplify small concrete jobs where speed and convenience matter. Instead of separately measuring cement, sand, aggregate, and additives, the dry blend is already proportioned in the bag. This helps reduce preparation time, improves consistency, and makes it easier to work on smaller fencing, landscaping, and post-setting tasks.
For post holes, rapid set concrete is typically poured around the positioned post and activated with clean water according to the product directions. As the mix begins to harden, it supports the post in the footing and reduces the time needed before the installation can continue. Correct post alignment, footing depth, hole diameter, and soil conditions still matter for the final result.
Rapid set concrete can be used for some concrete sleeper retaining wall post footings where the wall design, site conditions, and engineering requirements allow it. For retaining wall posts, the correct concrete volume depends on the post size, hole diameter, hole depth, wall height, soil type, surcharge load, and drainage conditions.
As a practical guide, many standard residential retaining wall post holes may require multiple 20kg bags per post. Always calculate based on the actual footing size, and allow extra material for variation in hole diameter, uneven excavation, and ground conditions.
For engineered retaining walls, taller walls, clay soils, surcharge loads, driveways, fences above the wall, or walls near structures, always follow the engineer's nominated concrete strength, footing depth, hole diameter, post size, and installation method.
Before using rapid set concrete, ensure the hole is dug to the correct depth and diameter for the post being installed. The post should be positioned, aligned, and braced before the concrete is added. Clean water should be used according to the manufacturer's directions, and the post should remain stable while the concrete sets.
Do not rely on rapid set concrete alone to compensate for poor footing design, shallow holes, weak soil, incorrect post spacing, or inadequate drainage. For retaining wall systems, the concrete footing works together with the steel post, concrete sleepers, backfill, and drainage system to resist soil pressure.
Rapid Set Bags 20kg 25MPa are available for delivery across Sydney, Melbourne, Brisbane, Perth, Adelaide, Canberra, Gold Coast, and regional Australia. Get a free quote for your retaining wall, fencing, or landscaping materials.
