Returned Concrete Recycling – How To Use MasterSuna RCT 323
MasterSuna RCT 323 is a new product that provides fast, efficient and extremely easy-to-use recycling solution for returned ready-mixed concrete waste.
MasterSuna RCT 323, is a single product admixture that allows ready-mixed concrete producers to develop a returned concrete solution that eliminates the need for onsite concrete crushing and disposal into landfills. Supplied in dissolvable, water-soluble bags which are added directly into the agitator drum of the ready-mixed concrete truck, MasterSuna RCT 323 admixture is a one-component engineered powdered polymer that gels the fresh concrete, resulting in very rapid stiffening while significantly minimising cement hydration and strength development.
Here’s how it works: Once the driver returns to the batch plant, they simply need to pull up to the slump stand, check that the mix has a slump of between 80 and 130 (water can be added to the returned concrete if required), and then add one bag of MasterSuna RCT 323 for every cubic metre of returned concrete or part thereof. Higher slump concretes can also be treated with a slightly higher dose rate.
Once the MasterSuna RCT 323 has been added to the mix, the agitator is spun up at maximum speed until the material gels. This process generally takes between 60-90 seconds and is clearly indicated by the changing sound coming from the barrel… it will sound like the barrel is only mixing aggregate rather than ready-mixed concrete!
At this stage the resulting material – which can be easily broken up and has a sandy gravel-type consistency similar - should be emptied in a suitable hardstand area (ideally as a small ‘windrow’) and then back-bladed with a loader to achieve a height of around 150-200mm across the pile or windrow. This material should then be left overnight to settle. The following morning, the material is ready to use, without the need for any additional screening or crushing.
“MasterSuna RCT 323 provides concrete suppliers with an extremely fast, efficient and easy to use to use method of closing the loop on a major waste stream,” Jason Bolt said.
“The speed of the process, together with the fact that it’s carried out in the drum as soon as the truck returns, helps to minimise delays for both the drivers and plant operators.”
“It’s simply a case of adding the bags, mixing for an average of 60-90 seconds, and then emptying the material. From there, it’s an extremely straightforward process of back-blading the treated returned concrete with a loader and letting it sit overnight. The next morning you’re left with a high quality gravel like material which breaks up extremely easily and is ideal for use as road base, construction backfill, or any number of applications,” Jason Bolt added.