Wollastonite Mineral Milling

Types Of Pavers

Pavers are widely used and are oftentimes enhanced - both visually and mechanically - by the inclusion of additives in their manufacture. Such pigments and minerals can add pleasing visual appearances and enhanced resistance to weathering, and include K37 and manganese oxide amongst many others - available to virtually any specification from African Pegmatite.

A paver is used for external flooring, often in the form of a stone, tile or brick. Before applying a paver, sand is spread atop a concrete foundation and afterwards, these pavers are set in the desired pattern. There isn’t a need for adhesives or retaining methods during the application of pavers. Roads, patios, driveways, and walkways are the few cases where pavers are used as external flooring.

Pavers are relied upon in many situations. Such usage relies upon the following qualities being met:

  • Strength
    A paver must be strong so as to be able to withstand heavy loads - this is largely a product of the major material used in their manufacture, such as concrete or cement.
  • Durability
    A paver must not be easily eroded or weathered - a uniform curing process combined with appropriately selected materials largely ensures durability.
  • Ease of use
    A paver must be of uniform shape and size - this arises from both the forming step and from curing.
  • Low cost of maintenance
    In a way a subset of durability, pavers must be easy to maintain, ideally with little to no maintenance required. This can arise from the choice of major material components and additives.
  • Visual appearance
    A paver should look good - as it is oftentimes visible. This is achieved using pigments and colourants, combined with controlled moisture levels in the pre-curing phase.

Types Of Pavers According To Materials

Brick Pavers

These pavers have been in use for many years. Brick pavers are manufactured from clay which undergoes a heating process in a kiln. They come in a range of colours and textures and can be used in the place of concrete pavers. Brick pavers are recyclable since they are produced from natural materials. Brick pavers have the benefit of the colour being fired into the brick thus no fading will happen over many years with very little maintenance being required.

brick pavers

Concrete Pavers

Concrete pavers are an inexpensive choice and more durable when compared with poured concrete. On the downside, these pavers can crack when subjected to extremely high temperatures. Concrete pavers that are coloured do have one large disadvantage that the colour can fade due to the exposure of sun, it is however a lot more cost effective compared to brick pavers.

concrete paving blocks
concrete pavers

Flagstone

As a sedimentary rock, flagstone has distinct shapes that fit perfectly with other pieces of its kind. It is often used in patios, but is considered unfit for use in driveways since it is thinner than brick or concrete pavers. It has higher durability compared with concrete and comes in a variety of hues and shapes – thus, flagstone is an ideal paving material for landscaping. Another merit accorded to flagstone is its non-slip texture which makes it an ideal flooring option. Compared to other types of pavers, flagstone is expensive due to the cost of transportation and mining accumulated in the total price.

flagstone

Travertine Pavers

Extreme temperature and pressure are required for the formation of these sedimentary rocks, often associated with hot springs. Travertine is a type of limestone. Its major use is in exterior flooring and landscaping. Interior floorings, patios and pool areas could also make do with travertine pavers. Fortunately, travertine pavers are readily available, plus they are eco-friendly and natural. From a positive perspective, travertine is durable and has excellent heat-insulating property. Furthermore, there isn’t a need to worry about the colour fading out, but users need to be careful when cleaning with strongly acidic methods as an undesirable stain is often left behind due to the acid base reaction between the calcium carbonate in the limestone and acid.

Marble Pavers

Marble is formed when limestone is subjected to extreme temperature and pressure. Marble pavers are used in patios, walkways, driveways and grass yard lanes. These pavers often give a regal and sophisticated appearance which isn’t the case with stones or granite. They are also supremely durable, but very expensive.

Cobblestone

These are usually produced from granite. However, basalt, sandstone or limestone can also be used in manufacturing cobblestone. These types of pavers have been around for centuries, giving us an idea about its durability. With cobblestone pavers, they only need a thorough wash once a year to refresh the appearance; and strength is its dominant feature. However, these pavers are costly and require more labour and skill to install them.

cobblestone

Porcelain

Porcelain is produced from clay that has been exposed to high temperature conditions. It is used for outdoor and indoor floorings, especially wet areas such as pool decks due to its reduced permeability to water. Modern technology allows manufacturers to produce porcelain pavers that have almost the same thickness as wood or stones. Porcelain requires kaolin for its production.

Colours For Paving Bricks

When considering colouring for brick or concrete pavers, the following considerations should be taken into account:

  • Pigments for bricks can add visual interest - yet many can be used in small quantities, making them very economically attractive
  • Depending on identity of pigment, enhanced properties such as longevity may be imparted
  • Typically, pigments are added before firing, therefore the colouration is even and persistent throughout the paver
  • Colouration added after firing (i.e. by painting or coating) will not be as durable as those added as pigments before firing

Single Colours

  1. Black: Some black bricks are formed when red firing clay is passed through high temperature and pressure condition in a kiln; after which, the finished product is dyed with K-37 black clay oxide which provide a lifetime of colour. K37 is a predominantly manganese and iron oxide based pigment designed specifically for the clay and ceramic space. Being typically milled to 45 μm means effective disbursement amongst the starting clay, and therefore an unmatched depth and uniformity of colour. Additionally, K37 pigmented ceramics/pavers are known for their longevity: the colour will not fade. African Pegmatite exclusively supplies K37 for a wide range of ceramic uses, where it is typically employed at between 6 and 12 weight% and can be fired up to 1,130 °C. For lower quality clays, K37B may be used, which has a firing tolerance of up to 1,080 °C. Anthracite and magnetite powder could also provide concrete pavers with a black hue but the colour will not last very long as the sun does bleach concrete pavers over time. These black bricks are used anywhere in the world and give the building a practical and modern appearance. Furthermore, the dirt particles brought on by air pollution are not visible on these bricks. Hence, you can have a appealing driveway or patio without worrying about an undesirable stain that might make these surfaces appear shabby.

 

  1. Brown: A common colour that has many applications and shades that can suite almost any environment. Manganese Umber brick oxide is a very cost effective pigment to achieve this colour and has become the de facto brown pigment for the ceramic industry owing to its good dispersibility and high levels of stability. Many hues and shades can be made with a naturally red firing clay with low and high temperatures giving you a large amount of flexibility in the production environment. Known for its strong colouring persistence, manganese umber often finds use in the 2 to 6 wt% regime, with higher values being commensurate with deeper brown colours. Standard milling is to ca. 45 μm with a manganese content averaging 47%, with lower manganese content variants available.

    For dark shades of brown or if you have a very low firing temperature then it is suggested that Mn3O4 brick oxide is used in your environment. MnO2 brick oxide is also a very common material added.

paving bricks
coloured bricks
  1. Grey: When chrome flour is added to ivory filing clays, paving bricks with attractive grey appearance are often produced. Brick's grey appearance on account of chrome flour is increasingly popular in architectural trends of today. K64 grey ceramic oxide and chrome flour can produce a range of grey hues that are attractive. although chrome flour is only used when the absolute highest performing paver is required, due to its expense relative to that of a paver. K64 itself is unique to African Pegmatite. It is a grey pigment that is composed primarily of iron and chromium oxides. Finely milled to ensure good dispersibility, highly effective grey pigmentation can be achieved with as little as 6 to 9 wt% being used in clay.

 

  1. Red: This colour is often used for borders of driveways or patios and when certain patterns like diamond are added. However, the red colour is not ideal for driveways with a wide perimeter since dirt and oil stains stand out in red. Red iron oxide is often used in producing concrete bricks with a red hue. Red coloured pavers may also arise from the natural colouration of red clay, if they are made through this method, the clay’s colour will persist. Furthermore, red pavers can be achieved by using red kaolinite - a material which adds a high plasticity component to the pre-fired material and also a low shrink-swell capability; together meaning that red kaolin is well suited to the manufacture of pavers in intricate or otherwise non-standard shapes.

 

  1. Buff: Buff paving has an almost-yellow hue and is ideal for driveway borders and designs with diamond shapes. It has a bright tone and as such, could be used to highlight certain features including smudge and oil spots. Yellow ochre is often used in achieving a yellow hue for these concrete paving bricks, with the pigment often outperforming synthetic iron pigments in terms of colour depth, longevity and vividness. It is a naturally occurring pigment consisting primarily of hydrated iron oxides. Milled to ca. 75 μm as standard, yellow ochre is well dispersed in clay and cement and will provide persistent colouration even at moderate loadings.

Mixed Colours

  1. Autumn: This is a blend of buff, red and brown colours. It is often used in more expensive concrete paving bricks to resemble the hue associated with autumn leaves.

 

  1. Brindle: This hue is a mix of red and charcoal colours and it is popularly used in the colour mix for block paving. Of the many paving bricks available in the market, those with a brindle hue comes at the most affordable price. It is advantageous in the sense that oil stains are not often visible in concrete paving bricks with this hue.
paving stones
variety of brick sizes and colours
  1. Heather: This is a combination of brown, charcoal and red pigments. However, some concrete paving bricks with heather hue can have a near resemblance to purple.

 

  1. Burnt Oker: Burnt ochre is a mixture of charcoal and brown hues. It is ideal for driveways and gives off the same effects with brindle visually. If the end user needs to hide oil spots and tire trails, a concrete paving brick with burnt ochre pigment would be a good choice.
black and red brick paver

Different Shapes Of Paving Bricks

Paving bricks come in a variety of shapes, especially those used as interlocking pavers. The different shapes include:

  1. Hexagon
  2. Square
  3. Wave
  4. Cross Dumble
  5. Round Dumble
  6. Arrow design
  7. Zig-Zag
  8. Colorado Design

Type Of Paving According To Features

  1. Interlocking Paver: To interlock means to link different parts such that the movement is restricted by another. Bricks and concrete are commonly used to produce interlocking pavers. When set on a driveway or patio, a cobblestone-like appearance is a result. Mortar isn't needed for installing interlocking pavers. Sand is enough material to set these pavers.

 

  1. Paving Slabs: Paving slab is favoured amongst homeowners and architects since it offers versatility. Slabs are manufactured in various shapes and colours and are used to serve various indoor and outdoor flooring purposes. They are durable and can withstand extreme weather conditions.
interlocking pavers

Summary

  • Pavers are widely used ceramic floor covering products, which may be used in the home, garden or in more municipal or industrial settings
  • Commonly composed mostly of concrete, cement or brick, pavers are strong and resistant to poor weather conditions and heavy traffic
  • Their utility and ubiquity means they are formed into a wide array of shapes and sizes
  • Pigmentation of pavers is possible, with the most profound colouration effects being realised when pigments are added to the pre-cured material
  • Post-curing treatment of a paver (such as with a paint or glaze) is viable but will not afford as resilient a product as one that was pigmented before firing

 

African Pegmatite is a leading processor and supplier of the widest range of pigments and additives for paver production, offering minerals that add unmatched colour depth and resilience to weather conditions including K37, manganese oxide, kaolin and red iron oxide amongst many others.

man putting in paving, concrete slabs