Interlock concrete pavers (ICPs)
ICPs are a manufactured concrete product, which is used as a paving material for walkways, patios, and driveways. In Canada, they are classified as any manufactured stone that has a surface area less than or equal to 0.09 m² (0.96 sf) with a minimum thickness of 60 mm (2.36 in.).
These ‘interlock’ pavers are designed to fit together as a module in a variety of patterns and configurations. The combination of the concrete pavers, aggregate sub-grade, bedding sand, jointing sand, and edge restraint allows the pavers to interlock as a system.
As a single system, pavers are able to move independently while avoiding any cracking as the substrate shifts during freeze-thaw cycles. This flexibility also allows for the dispersal of weight from heavy loads such as vehicular traffic.
Manufacturing
In the past, ICP selection was limited to a few shapes and colours. Today’s manufacturers offer dozens of styles and laying patterns to choose from, which can complement any home’s architecture. Styles range from sleek, large-scale pavers for contemporary, modern-styled homes to those that are rustic in appearance and look like natural flagstone. Pavers are manufactured in thicknesses of 60 to 80 mm (2.36 to 3.14 in.) and in a multitude of sizes depending on the chosen product.
In the ’90s, the tumbled paver revolutionized the ICP industry offering a more rustic natural appearance. This rough texture was initially a simple manufacturing process. Ordinary pavers were ‘tumbled’ through a large rotating drum, which would chip and distress the paver edges and corners giving the paver a cobblestone appearance. As manufacturing technology progressed, more elaborate pavers were being created with natural textures, special edge treatments, and finishes.
Most of today’s ICPs are manufactured in a ‘dry-cast’ process, which consists of combining fine aggregate materials with cement powder and compressing them under extreme pressure with the minimum required amount of moisture. This yields a denser, more durable product that is capable of withstanding heavy loads.
This process also provides precise control on the percentage of raw materials added during the manufacturing process. Manufacturers are able to use crushed marble, granites, and other small aggregates—in combination with natural colour pigments—to create pavers that look like natural stone. By controlling the colouring, other products such as retaining wall stone, copings, and caps can be manufactured to complement the pavers in the same colours and tones.
Segmental concrete paving slabs
Segmental concrete paving slabs share many of the same characteristics and installation methods as ICPs. The most notable difference between the two is that concrete paving slabs are much larger. Paving slabs do not possess the same interlocking qualities as ICPs. Due to the lack of interlocking ability and the sheer size of the slabs, this material does not disperse weight as efficiently and, therefore, is more prone to cracking.
Segmental concrete paving slabs are classified as any manufactured stone that has a surface area greater than 0.09 m² (0.96 sf) with a minimum thickness of 30 mm (1.2 in.) and a maximum overall length or width of 1 m (3.3 ft).
Manufacturing
Segmental concrete paving slabs are manufactured using the same ‘dry-cast’ process used to make ICPs. Many manufacturers also use a ‘wet-cast’ process, which involves pouring a liquid mixture of cement, small aggregates, and colour pigments into a mould to cast the shape of the slab. These moulds are recreated from casting actual natural stones.
Hundreds of stones can be cast to recreate a random natural appearance with a realistic embossed surface texture. Granite, marble, and other natural ingredients can be used in the cement mixture to allow for a range in tones, veining, and textures.
I like the idea of using natural stone as a paver in my hardscaping project, and I agree that no two stones are alike. That unique style to each stone would really resonate with the rest of my yard, where I’m really trying to create a very natural woodsy feel with lots of trees and a fountain. I like how you break down the history and uses of each stone, and I really like the earthy tones you describe for limestone; I’ll have to talk to a contractor about paving with that.
http://www.decorativecreations.com/services/hardscaping.html
It’s very interesting to know what paving paths and walkways date back to well before the rise of the Roman Empire, even before they became ornamental elements to landscaped lawns. The difference though is in the type of stone pavers to use, which now can be made to the client’s choice of color, texture, pattern, and cost. I appreciate this fact because we’re planning to preserve our big lawn at the country house and paving stones would definitely help save our manicured grass lawns from getting trampled upon by wheels and feet. Comprehensive article for reference here! http://www.decorativecreations.com/hardscaping
Thank you for explaining what hardscaping is. My husband would love to have nice paving in our backyard. I am sure that we could find a great company to install them for us! http://whiteoaklm.com