Kayasand-manufactured sand uses up to 20 per cent less cement than natural sand to create concrete of the same strength.
Kayasand believes quarries are critical to the construction industry’s goal of achieving net-zero carbon emissions by 2050.
The United Nations warning of a global sand shortage was described by United Nations Environment Programme’s Pascal Peduzzi as the “elephant in the room” for the 21st century.
The world’s second most consumed material is used to make roads, bridges and houses. Given the world’s reliance on natural sand in concrete creation, the “elephant in the room” left many searching for sustainable alternatives.
Manufactured sand is often used as a substitute for natural sand in concrete, especially in areas where accessible natural sand sources are scarce or of poor quality. This is also true in countries where heavy government regulation limits companies mining natural sand for construction.
Manufactured sand used to be solely about repurposing surplus quarry materials, like crusher dust. It was often labelled unequal to natural sand in concrete production, especially in developed construction industries. However, it has come a long way since it first entered the market.
Kayasand believes with the innovative technology available today, it’s more consistent in quality and performance and can be precisely engineered for specific construction applications.
When processed well, this ‘engineered’ sand has many advantages over traditionally manufactured sands: precise shape, good particle size distribution, no contamination, and regular consistency. In fact, it produces stronger concrete than many natural sands with less cement.
Kayasand trials show that concrete made with Kayasand-manufactured sand uses up to 20 per cent less cement than natural sand to create concrete of the same strength.
While most countries support the future of manufactured sand, not all of them have embraced its potential. New Zealand Green Investment Finance delivered $3.5 million earlier this year to support Kayasand’s first V7 high-technology manufacturing demonstration plant in the Waikato region of New Zealand.
Global bodies, including the United Nations, have warned about the shortage of natural sand and the need to reduce carbon emissions, so manufactured sand is set to become an increasingly critical construction material.
A United Nations Environment Programme report suggests that 50 billion tons of sand and gravel are used yearly. This makes it the second most used resource after water.
In an interview with Quarry, Kayasand’s national sales manager, Frank Grech, said the opportunity for quarries selling manufactured sand is better than ever.
The process
Innovative technology, like Kayasand’s Kemco quad-deck air screens and V7 sand plants, makes the process dust-free, low-noise and uses no water for washing. This means quarries no longer need sediment ponds or water tailings and there are no hidden costs for water management.
Kayasand’s unique design combines the accuracy of mesh screens with the high throughput of air classification system. Their equipment specialises in screening materials that have high fines content. The fully enclosed nature of the V7 plant limits dust exposure, while its negative pressure from the built-in dust extractor keeps dust contained and away from operators.
Waste glass can be recycled into concrete sand. Cement substitutes can be created from limestone filler and waste slag using Kayasand’s V7 plant.
Grech says this versatility allows quarries to reduce their environmental impact while increasing revenue opportunities and enabling a circular economy
Researchers are exploring ways to enhance the properties of manufactured sand for use in sustainable concrete mixes.
By incorporating manufactured sand in innovative concrete formulations (such as carbon-sequestering concrete or high-performance, sustainable concrete), the construction industry can reduce its carbon footprint per unit of construction material.
Grech said engineering sand to have highly consistent properties, allows for more precise and optimised concrete mix designs.
This can lead to reduced material wastage during construction, which, in turn, facilitates a project’s overall carbon footprint.
ENVIRONMENTAL BENEFITS
Using manufactured sand enables the construction industry to minimise waste generation and maximise resource utilisation to align with sustainable development principles and carbon reduction reporting requirements.
It helps to conserve natural resources by reducing the riverbed and coastal sand demand. Preserving these ecosystems can help mitigate carbon emissions associated with habitat destruction.
Manufactured sand produced in quarries is often closer to construction sites, reducing the need for long-distance transportation. Producing sand locally allows quarries to help reduce transportation emissions.
Grech said transporting natural sand over significant distances can result in higher emissions due to fuel consumption.
Given this and companies are trying to
find ways to lower costs, it makes sense to
embrace sustainable materials, like high
quality, ‘engineered’ sand, and move
towards a circular economy.
Peduzzi, who coordinated the United Nations Environment Programme’s report on the sand shortage, has supported the push for such an economy.
“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,” he said.
“To achieve sustainable development, we need to drastically change the way we produce, build and consume products, infrastructures and service.”
The environmental benefits, lower carbon footprint, repeatable design quality, and circular economic potential make manufactured sand a viable and scalable solution.
By embracing manufactured sand, the construction industry across the value chain can build a more sustainable future.
As the construction industry sets its sights on achieving net-zero emissions by 2050, quarries that sell quality manufactured sand are essential to the vision. •
For more information, visit kayasand.com