Premix 15 min Concrete Mix

Our high performance commercial grade concrete mix which is suitable for use in original construction and repair projects.

Mastermix Premix 15 Minute Concrete is an extremely quick setting commercial concrete mix which is suitable for projects where speed is paramount. R15 sets the standard for products in this class hardening in just 15 minutes while maintaining the same performance characteristics as our Premix range.

Selecting the right ready mix concrete product to suit your project’s specific requirements can be difficult. MasterMix and Packaging Limited is here to save you time and money by walking you through the selection process. We will ensure that you find the products and materials you need to complete your job to the highest standard.


Product Performance As part of our commitment to developing the best products for your projects, Mastermix has maintained a 20 year history of rigorous testing via internationally recognised laboratories. We pay top dollar to put our products to the test so you don’t have to. OPUS Laboratory Results: Independent tests through OPUS have shown results of better than 20Mpa after 7 days, and better than 30Mpa after 28 days.Further, RTU has been scientifically proven to meet and exceed NZ Standards: 3109 Concrete Construction and 3101:2006 Concrete Structures.
Packaging R15 comes packaged in 20kg and 30kg weatherproof bags with a shelf life of 3 months when kept in cool, dry conditions. Our proprietary process ensures the perfect mix of aggregates and admixtures meaning you can create the ideal concrete for your job every time.
Instructions R15 should be mixed thoroughly and evenly with clean for use potable water at 4 liters to the 30kg bag. Quickly mix to wet all the product then place into hole. IMPORTANT: Water should not be poured separately into a post hole before mixing Rapid Mix products as it may compromise the integrity of the project.
Coverage & Performance 1 bag of R15 yields 0.018 mɜ approx. Based on a 250mm hole diameter 2 bags are needed for a 1.8m Post. Compression tests have shown results of better than 20Mpa after 7 days, and better than 30 Mpa after 28 days. This product sets in 15 minutes. R15 meets and exceeds NZS: 3109 and NZS: 3101:2006
Warranty As part of our commitment to delivering the best customer experience throughout the project lifecycle, Mastermix Director Steve Douglas personally reviews each warranty request. Each Warranty period is awarded at our discretion and will only be considered where approved Mastermix product applicators are used.


R15 is a cement based product and contains no additional aggressive products. See packaging for full details.

The ambient temperature affects the curing time of R15. It is best used in temperatures between 7ᵒC and 25ᵒC. The water content will also affect the setting and curing time. Ensure that the entire product is wet through on placement.

Although the technical details and recommendations Contained in this document correspond to the best of our knowledge and experience, all the above information must in every case be taken as merely indicative and subject to confirmation after long term practical applications. For this reason, anyone who intends to use the product must ensure, beforehand, that it is suitable for the envisaged  application. In every case, the user alone is fully responsible for any consequences deriving from the use of the product.

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