{"product_id":"rapid-set-bags-20kg-25mpa","title":"RAPID SET Bags 20kg 25mpa","description":"\u003ch2\u003eRapid Set Bags 20kg 25MPa\u003c\/h2\u003e\n\n\u003cp\u003eRapid 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.\u003c\/p\u003e\n\n\u003cp\u003eWith a fully cured compressive strength of \u003cstrong\u003e25MPa\u003c\/strong\u003e, 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.\u003c\/p\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct type:\u003c\/strong\u003e Rapid set concrete bag\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBag size:\u003c\/strong\u003e 20kg\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConcrete strength:\u003c\/strong\u003e 25MPa when fully cured\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMix type:\u003c\/strong\u003e Ready-to-use blend of cement, aggregate, sand, and additives\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWater requirement:\u003c\/strong\u003e Add clean water as directed\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSetting time:\u003c\/strong\u003e Hardens in approximately 15 minutes when used as directed\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eApplications:\u003c\/strong\u003e Fence posts, clothes lines, letter boxes, garden posts, poles, logs, and selected retaining wall post footing applications where suitable\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eBest use:\u003c\/strong\u003e Fast-setting outdoor post and general landscape fixing work\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eTechnical Overview\u003c\/h3\u003e\n\n\u003cp\u003eRapid 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.\u003c\/p\u003e\n\n\u003cp\u003eFor 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.\u003c\/p\u003e\n\n\u003ch3\u003eWhy Use Rapid Set Concrete?\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFast setting:\u003c\/strong\u003e Hardens quickly when used as directed, helping speed up post installation work.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReady to use:\u003c\/strong\u003e No separate mixing of cement, sand, and aggregate is required.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e25MPa strength:\u003c\/strong\u003e Provides reliable cured strength for suitable outdoor fixing and post-setting applications.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConvenient 20kg bag:\u003c\/strong\u003e Easy to transport, handle, and calculate for smaller jobs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUseful for post holes:\u003c\/strong\u003e Suitable for fence posts, letter boxes, clothes lines, and similar outdoor posts.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eGood for small projects:\u003c\/strong\u003e Practical for garden, fencing, and landscape jobs where only a few bags are needed.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eCommon Applications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eFence post installation\u003c\/li\u003e\n\u003cli\u003eClothes line footings\u003c\/li\u003e\n\u003cli\u003eLetter box posts\u003c\/li\u003e\n\u003cli\u003eGarden posts and small poles\u003c\/li\u003e\n\u003cli\u003eLandscape edging supports\u003c\/li\u003e\n\u003cli\u003eSmall outdoor fixing jobs\u003c\/li\u003e\n\u003cli\u003eSelected concrete sleeper retaining wall post holes where rapid set concrete is allowed by the wall design\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eUsing Rapid Set for Retaining Wall Posts\u003c\/h3\u003e\n\n\u003cp\u003eRapid 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.\u003c\/p\u003e\n\n\u003cp\u003eAs 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.\u003c\/p\u003e\n\n\u003cp\u003eFor 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.\u003c\/p\u003e\n\n\u003ch3\u003eInstallation Considerations\u003c\/h3\u003e\n\n\u003cp\u003eBefore 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.\u003c\/p\u003e\n\n\u003cp\u003eDo 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.\u003c\/p\u003e\n\n\u003ch3\u003eCompatible Products\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eStandard C-channel post option:\u003c\/strong\u003e \u003ca href=\"\/products\/galvanised-steel-c-posts-100mm-100pfc\"\u003eGalvanised Steel C Posts – 100mm 100PFC\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHeavy-duty C-channel post option:\u003c\/strong\u003e \u003ca href=\"\/products\/galvanised-steel-c-posts-150mm-150pfc\"\u003eGalvanised Steel C Posts – 150mm 150PFC\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStandard H post option:\u003c\/strong\u003e \u003ca href=\"\/products\/galvanised-steel-h-posts-100mm-100uc-uc-14-8\"\u003eGalvanised Steel H Posts 100mm 100UC – UC 14.8\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHeavy-duty H post option:\u003c\/strong\u003e \u003ca href=\"\/products\/galvanised-steel-h-posts-150mm-uc23-4\"\u003eGalvanised Steel H Posts 150mm UC23.4\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eConcrete sleeper range:\u003c\/strong\u003e \u003ca href=\"\/collections\/concrete-sleepers\"\u003eConcrete Retaining Wall Sleepers\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrainage product:\u003c\/strong\u003e \u003ca href=\"\/products\/ag-pipe-100mm-x-20m\"\u003eAg Pipe 100mm x 20m\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eGuides and Resources\u003c\/h3\u003e\n\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eFooting depth guide:\u003c\/strong\u003e \u003ca href=\"\/blogs\/news\/retaining-wall-footings-depth-concrete\"\u003eRetaining Wall Footings: Depth, Size and Concrete Guide\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterials calculator guide:\u003c\/strong\u003e \u003ca href=\"\/blogs\/news\/how-to-calculate-sleepers-posts-retaining-wall\"\u003eHow to Calculate Sleepers and Posts for a Retaining Wall\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstallation guide:\u003c\/strong\u003e \u003ca href=\"\/blogs\/news\/how-to-build-concrete-sleeper-retaining-wall\"\u003eHow to Build a Concrete Sleeper Retaining Wall\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePost spacing guide:\u003c\/strong\u003e \u003ca href=\"\/blogs\/news\/retaining-wall-post-spacing-guide\"\u003eRetaining Wall Post Spacing Guide\u003c\/a\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDrainage guide:\u003c\/strong\u003e \u003ca href=\"\/blogs\/news\/retaining-wall-drainage-guide\"\u003eRetaining Wall Drainage Guide\u003c\/a\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eDelivery\u003c\/h3\u003e\n\n\u003cp\u003eRapid Set Bags 20kg 25MPa are available for delivery across Sydney, Melbourne, Brisbane, Perth, Adelaide, Canberra, Gold Coast, and regional Australia. \u003ca href=\"\/pages\/book-a-quote\"\u003eGet a free quote\u003c\/a\u003e for your retaining wall, fencing, or landscaping materials.\u003c\/p\u003e\n","brand":"Retaining Walls Direct","offers":[{"title":"Default Title","offer_id":52288012058904,"sku":null,"price":18.09,"currency_code":"AUD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0952\/5595\/3688\/files\/QPro_2025_RapidSetBags_20kg_25mpa-600x600.webp?v=1781591380","url":"https:\/\/www.retainingwallsdirect.com.au\/products\/rapid-set-bags-20kg-25mpa","provider":"Retaining Walls Direct","version":"1.0","type":"link"}