The plants use technology that was originally developed in Japan due to a ban on dredging. Image: Kayasand
Shortages of quality natural sand are creating headaches for the concrete industry, but Kayasand believes quarries can provide the solution.
Sand remains a key component of concrete – but keeping up with demand is increasingly difficult.
In 2022, the United Nations Environment Programme (UNEP) called the global sand extraction rate “unsustainable”. The group urged for sand to be considered a “strategic resource” given its importance to construction and the environment.
“If we can get a grip on how to manage the most extracted solid material in the world, we can avert a crisis and move toward a circular economy,” Pascal Peduzzi, director of GRID-Geneva at UNEP, said at the time.
Not all sand is created equally, and the amount of sand required compared with the cost of shipping it is often not economically viable. On top of this, there are only certain sites that are allowed to extract sand, further limiting supply.
Frank Grech, Kayasand’s national sales manager, told Quarry that there is another proven way.
“I have been in the industry for a long time,” he said. “When natural sand was readily available, there was no reason not to use it.”
“But now it’s getting much harder to access while demand is getting higher and higher. There’s also been a lot of publicity about the scarcity of quality natural sand, which is bringing it front of mind for people.”
Kayasand’s solution to the growing demand for quality concrete sand is its V7 engineered sand plants.
The specialist crusher and air screen technology was originally developed by Kemco in Japan because of a ban on dredging. The plants engineer crusher dust (a byproduct of quarrying) into a high-quality sand that’s ideal for concrete.
In fact, in a recent concrete trial with a normal Auckland mix design, sand engineered from Greywacke-based crusher dust was used to replace 100 per cent natural sand. The resulting concrete proved to be 24 per cent stronger and used 10 per cent less cement.
A member of the Institute of Quarrying Association (Waikato Chapter) feeling the quality of concrete sand engineered on the Kayasand demonstration plant. Image: Kayasand
Grech said the final product is a concrete technologist’s dream.
“You don’t need to blend the product – it comes straight out, ready to go,” he said.
“That’s because we precisely control the shape and size of the sand particles, the levels of contaminants and consistency of the final product. Not only does engineered sand make the concrete mix stronger, but it also needs less cement to do it
“Manufacturing cement emits a lot of carbon into the atmosphere, so an easy way to cut down on your emissions is to simply use less of it.”
Kayasand’s process can be meticulously controlled to meet certain specifications, if required. This also helps to improve the pumpability and finish of the final concrete mix.
In 2023, the company received a $3.5 million investment from New Zealand Green Investment Finance to reduce carbon emissions from concrete. With this cash injection, it opened the first V7 high-technology demonstration plant in New Zealand.
The company has invited major aggregate suppliers to test out the plant to see if the crushing technology could provide the right solution. One Australian supplier sent 40 tonnes of aggregate to the plant in New Zealand as a high volume trial.
Grech said Kayasand plans to expand across Australia and New Zealand.
“People are realising the full potential of what’s on offer, and that quarries play an important part in meeting the growing demand for concrete sand,” he said.
“The industry has been using concrete for a very long time. It allows builders to create versatile and durable structures – it’s even being used in 3D printing and precast construction.
“We want to help the industry innovate and believe quarries are part of the solution to meet the growing demand for concrete sand. We have the plant and equipment to help. Our technology is proven and it’s already out there in the market being used.” •
For more information, visit kayasand.com
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