A paver is a paving stone, tile, [1] brick [2] or brick-like piece of concrete commonly used as exterior flooring. They are generally placed on top of a foundation which is made of layers of compacted stone and sand. The pavers are placed in the desired pattern and the space between pavers that is created with the integrated spacer bar is then filled with concrete sand or a polymeric sand. No actual adhesive or retaining method is used other than the weight of the paver itself except edging. Pavers can be used to make roads, driveways, patios, walkways and other outdoor platforms.
In a factory, concrete pavers are made with a mixture of sand, stone, cement and iron oxide pigments in a mold and then cured prior to packaging.
Block paving, also known as brick paving, is a commonly used decorative method of creating a pavement or hardstanding. The main benefit of bricks over other materials is that individual bricks can later be lifted up and replaced. This allows for remedial work to be carried out under the surface of the paving without leaving a lasting mark once the paving bricks have been replaced. Typical areas of use would be for driveways, pavement, patios, town centres, pedestrian precincts and more commonly in road surfacing. Bricks are typically made of concrete or clay, though other composite materials are also used. Each has its own means of construction. The biggest difference is the way they set hard ready for use. A clay brick has to be fired in a kiln to bake the brick hard. A concrete brick has to be allowed to set. The concrete paving bricks are a porous form of brick formed by mixing small stone hardcore, dyes, cement and sand and other materials in various amounts. Many block paving manufacturing methods are now allowing the use of recycled materials in the construction of the paving bricks, such as crushed glass and crushed old building rubble.
There are many different laying patterns that can be achieved using block paving. The most common of these is the herringbone pattern. This pattern is the strongest of the block paving bonds as it offers the most interlock, therefore making it a good choice for driveways and road surfacing. A herringbone pattern can be created by setting the blocks at either 45 degrees or 90 degrees to the perpendicular. Other popular types of pattern include stretcher bond and basketweave; with the latter being better suited to paved areas that will only receive light foot traffic, due to its weaker bond.
A commonly used base is 'cracker dust' or commonly known as crushed bluemetal. The advantage of using this in residential living is that it compacts a lot harder than yellow brickies sand, which prevents weeds and ants from coming through.
Pavers come in a number of styles, shapes and tones. Pavers manufactured from concrete go well with flag, brick and concrete walkways or patios. Concrete pavers may be used where winter temperatures dip below freezing. They are available in hole, x-shape, y-shape, pentagon, polygon and fan styles.
An interlocking concrete paver, also known as a segmental paver, is a type of paver. This paver has emerged over the last couple of decades as a very popular alternative to brick, clay or concrete. [3] An interlocker is a concrete block paver which is designed in such a way that it locks in with the next paver. The locking effect allows for a stronger connection between pavers and with this interlocking effect the paving itself is resistant to movement under traffic. [4]
Segmental pavers have been used for thousands of years. The Romans built roads with them that are still there. But it was not until the mid-1940s that pavers began to be produced out of concrete. It started in the Netherlands [3] where all the roads are made to be flexible because much of the country is below sea level and the ground shifts, moves and sinks. Poured concrete is not an option because it will crack. Individual units not set in concrete, and placed in sand perform far better than concrete. [3] Before the paver was made from concrete, either real stone or a clay product was used.
The first production of concrete pavers in North America was in Canada, in 1973. Due to their success, paving stone manufacturing plants began to open throughout the United States working their way from east to west. [5]
The first concrete pavers were shaped just like a brick, 4 by 8 inches (100 mm × 200 mm), and they were called Holland Stones. These units turned out to be economical to produce and were exceedingly strong.
In addition to being economical, interlocking concrete pavers are also widely available in water-permeable designs, which have added ecological benefits. [6] By allowing water to drain through the pavers in a way that mimics natural absorption, builders and landscapers are able to limit surface runoff [7] and prevent soil erosion or buildup of standing water in the surrounding land area. Some permeable paver installations are designed to harvest rainwater, which can then be repurposed for uses such as irrigation or washing a car. [8] Permeable paver applications have also been found to offer benefits in filtering contaminants of the water being captured.
Pavers must have a strong base, a flat bedding and an edge restraint.
To prevent the soil from absorbing the base layer above, there should be a compacted sub-base (which is the naturally occurring soil) and a layer of landscape fabric. [9] Landscape fabric is not required in every application. All compaction is usually performed with a plate compactor or hand tamper. All sand-containing materials (e.g., concrete sand, rock dust, or minus crushed rock) must be soaked with water for effective compaction. The base layer should be 6" deep for walkways, or 12" deep for driveways. [10] The base material should either be 3/4" crushed stone (to allow water to drain through it) for a 1/4" crushed stone bedding, or 3/4" minus crushed stone (to prevent sand from sinking through it) for a concrete sand bedding. The base should be compacted every 6". [11] [9] If the base layer is deeper than 6", then biaxial geogrid should be added every 6" and spaced evenly throughout the bedding to maintain stability. [12] If reliable concrete is already installed that can be used as the base layer.
Above the base layer, there should be a 1" bedding layer. A 1/4" crushed stone bedding material is favored over concrete sand on walkways for its better drainage that mitigates freeze-thaw shifting, easier compaction especially on rainy days, and less weed growth. [9] A concrete sand (specifically ASTM C33) bedding is preferable for building driveways with tighter joints (i.e., thinner cracks) because the sand is small enough to be raised up into the cracks when the pavers are compacted. This raised concrete sand helps lock the pavers in place so that they can handle more weight. [9] [10]
Concrete sand is a more preferable bedding layer than rock dust. Because rock dust retains rather than drains water, it prevents polymeric sand from drying and curing. Additionally, when that water in the rock dust eventually evaporates, it will carry salts through the pavers which will deposit on their surface and stain them with "efflorescence build-up". [13] Additionally, compacting pavers levels them easier on sand than on rock dust. [14]
The bedding layer must be flattened by "screeding" it. To screed the bedding, scrape a straightedge (such as a level) along the top of the bedding. To guide the straightedge, it is common to place parallel metal rails on top of the bedding, or have 1" PVC pipes laid on the base so that they reach the top of the bedding. If using pipes, their indentation must be filled with bedding material once removed. A slight slope towards a drain is usually implemented. The pavers are hammered with a mallet when placing them down to help them settle and prevent them from wobbling. [15]
Edge restraints prevent pavers from spreading apart and maintain the integrity of the pavement system to move uniformly with freeze thaw cycles as well. An edge restraint can be a concrete slope which is no steeper than 45 degrees, and meets the edge pavers halfway between its top and bottom surface so that it can be buried. Alternatively, commercial plastic edge restraints can be anchored into the ground with steel spikes.
After the pavers have been laid and cleaned with a pressure washer, and they must be dried according recommendations the particular polymeric sand (usually at least for one hot summer day). After they have been dried, sweep the polymeric sand into the cracks, then compact the pavers to help the sand sink in (often with a wood panel between the pavers and the compactor to prevent chipping the pavers), and then rinse according to the polymeric sand's instructions. This sand prevents weeds from growing between them, and helps them lock into place. [16] [17] Do not sweep the polymeric sand more than 10 feet from where it was poured because it will sift out necessary additives. Note that different types of polymeric sand can handle different joint widths and depths, and they often have require slightly different methods of rinsing. [18] Applying paver sealer or concrete sealer bi-annually prevents stains from getting on the pavers. [15]
A stone paver is another type of paver. This type of paver is used widely in building and landscaping as it is highly prized for beauty, strength and durability. Stone pavers are made of many materials including limestone, bluestone, basalt (such as that from The Palisades used in New York City), sandstone and granite. [19]
Travertine is a durable, low-porous stone that stays cool in direct sunlight, making it a popular choice for pool-sides, patios, walkways and outdoor entertainment areas. Travertine is salt tolerant and has a low sunlight reflection. Granite pavers have high integral strength and density making it easy to maintain and hard-wearing in outdoor use. Limestone pavers are cut from natural limestone blocks, a sedimentary rock found in mountainous areas and ocean sea beds. Limestone tends to have unique natural colour variations. Sandstone pavers are derived from natural stone and tend to be used for sidewalks, patios and backyards.
A sidewalk, pavement, footpath in Australia, India, New Zealand and Ireland, or footway is a path along the side of a road. Usually constructed of concrete, pavers, brick, stone, or asphalt, it is designed for pedestrians. A sidewalk is normally higher than the roadway, and separated from it by a curb. There may also be a planted strip between the sidewalk and the roadway and between the roadway and the adjacent land.
Tarmacadam is a concrete road surfacing material made by combining tar and macadam, patented by Welsh inventor Edgar Purnell Hooley in 1902. It is a more durable and dust-free enhancement of simple compacted stone macadam surfaces invented by Scottish engineer John Loudon McAdam in the early 19th century. The terms "tarmacadam" and tarmac are also used for a variety of other materials, including tar-grouted macadam, bituminous surface treatments and modern asphalt concrete.
Pavement(s) or paving may refer to:
A road surface or pavement is the durable surface material laid down on an area intended to sustain vehicular or foot traffic, such as a road or walkway. In the past, gravel road surfaces, macadam, hoggin, cobblestone and granite setts were extensively used, but these have mostly been replaced by asphalt or concrete laid on a compacted base course. Asphalt mixtures have been used in pavement construction since the beginning of the 20th century and are of two types: metalled (hard-surfaced) and unmetalled roads. Metalled roadways are made to sustain vehicular load and so are usually made on frequently used roads. Unmetalled roads, also known as gravel roads or dirt roads, are rough and can sustain less weight. Road surfaces are frequently marked to guide traffic.
Asphalt concrete is a composite material commonly used to surface roads, parking lots, airports, and the core of embankment dams. Asphalt mixtures have been used in pavement construction since the beginning of the twentieth century. It consists of mineral aggregate bound together with bitumen, laid in layers, and compacted.
Macadam is a type of road construction pioneered by Scottish engineer John Loudon McAdam around 1820, in which crushed stone is placed in shallow, convex layers and compacted thoroughly. A binding layer of stone dust may form; it may also, after rolling, be covered with a cement or bituminous binder to keep dust and stones together. The method simplified what had been considered state-of-the-art at that point.
Permeable paving surfaces are made of either a porous material that enables stormwater to flow through it or nonporous blocks spaced so that water can flow between the gaps. Permeable paving can also include a variety of surfacing techniques for roads, parking lots, and pedestrian walkways. Permeable pavement surfaces may be composed of; pervious concrete, porous asphalt, paving stones, or interlocking pavers. Unlike traditional impervious paving materials such as concrete and asphalt, permeable paving systems allow stormwater to percolate and infiltrate through the pavement and into the aggregate layers and/or soil below. In addition to reducing surface runoff, permeable paving systems can trap suspended solids, thereby filtering pollutants from stormwater.
Cobblestone is a natural building material based on cobble-sized stones, and is used for pavement roads, streets, and buildings. Setts, also called Belgian blocks, are often referred to as "cobbles", although a sett is distinct from a cobblestone by being quarried and shaped into a regular form, while cobblestones are naturally occurring forms less uniform in size.
Portuguese pavement, known in Portuguese as calçada portuguesa or simply calçada, is a traditional-style pavement used for many pedestrian areas in Portugal. It consists of small pieces of stone arranged in a pattern or image, like a mosaic. It can also be found in Olivença and throughout former Portuguese colonies, especially in Brazil. Portuguese workers are also hired for their skill in creating these pavements in places such as Gibraltar. Being usually used in sidewalks, it is in town squares and atriums that this art finds its deepest expression.
Soil cement is a construction material, a mix of pulverized natural soil with small amount of portland cement and water, usually processed in a tumbler, compacted to high density. Hard, semi-rigid durable material is formed by hydration of the cement particles.
In highway engineering, subbase is the layer of aggregate material laid on the subgrade, on which the base course layer is located. It may be omitted when there will be only foot traffic on the pavement, but it is necessary for surfaces used by vehicles.
Construction aggregate, or simply aggregate, is a broad category of coarse- to medium-grained particulate material used in construction, including sand, gravel, crushed stone, slag, recycled concrete and geosynthetic aggregates. Aggregates are the most mined materials in the world. Aggregates are a component of composite materials such as concrete and asphalt; the aggregate serves as reinforcement to add strength to the overall composite material. Due to the relatively high hydraulic conductivity value as compared to most soils, aggregates are widely used in drainage applications such as foundation and French drains, septic drain fields, retaining wall drains, and roadside edge drains. Aggregates are also used as base material under foundations, roads, and railroads. In other words, aggregates are used as a stable foundation or road/rail base with predictable, uniform properties, or as a low-cost extender that binds with more expensive cement or asphalt to form concrete. Although most kinds of aggregate require a form of binding agent, there are types of self-binding aggregate which require no form of binding agent.
Stone mastic asphalt (SMA), also called stone-matrix asphalt, was developed in Germany in the 1960s with the first SMA pavements being placed in 1968 near Kiel. It provides a deformation-resistant, durable surfacing material, suitable for heavily trafficked roads. SMA has found use in Europe, Australia, the United States, and Canada as a durable asphalt surfacing option for residential streets and highways. SMA has a high coarse aggregate content that interlocks to form a stone skeleton that resists permanent deformation. The stone skeleton is filled with a mastic of bitumen and filler to which fibres are added to provide adequate stability of bitumen and to prevent drainage of binder during transport and placement. Typical SMA composition consists of 70−80% coarse aggregate, 8−12% filler, 6.0−7.0% binder, and 0.3 per cent fibre.
Crushed stone or angular rock is a form of construction aggregate, typically produced by mining a suitable rock deposit and breaking the removed rock down to the desired size using crushers. It is distinct from naturally occurring gravel, which is produced by natural processes of weathering and erosion and typically has a more rounded shape.
A snowmelt system prevents the build-up of snow and ice on cycleways, walkways, patios and roadways, or more economically, only a portion of the area such as a pair of 2-foot (0.61 m)-wide tire tracks on a driveway or a 3-foot (0.91 m) center portion of a sidewalk, etc. It is also used to keep entire driveways and patios snow free in snow prone climates. The "snow melt" system is designed to function during a storm to improve safety and eliminate winter maintenance labor including shoveling, plowing snow and spreading de-icing salt or traction grit (sand). A snowmelt system may extend the life of the concrete, asphalt or under pavers by eliminating the use of salts or other de-icing chemicals, and physical damage from winter service vehicles. Many systems are fully automatic and require no human input to maintain a snow/ice-free horizontal surface.
Cellular confinement systems (CCS)—also known as geocells—are widely used in construction for erosion control, soil stabilization on flat ground and steep slopes, channel protection, and structural reinforcement for load support and earth retention. Typical cellular confinement systems are geosynthetics made with ultrasonically welded high-density polyethylene (HDPE) strips or novel polymeric alloy (NPA)—and expanded on-site to form a honeycomb-like structure—and filled with sand, soil, rock, gravel or concrete.
Concrete is produced in a variety of compositions, finishes and performance characteristics to meet a wide range of needs.
Decomposed granite is a kind of granite rock that is weathered to the point that the parent material readily fractures into smaller pieces of weaker rock. Further weathering yields material that easily crumbles into mixtures of gravel-sized particles known as grus that further may break down to produce a mixture of clay and silica sand or silt particles. Different specific granite types have differing propensities to weather, and so differing likelihoods of producing decomposed granite. It has practical uses that include its incorporation into roadway and driveway paving materials, residential gardening materials in arid environments, as well as various types of walkways and heavy-use paths in parks. Different colors of decomposed granite are available, deriving from the natural range of granite colors from different quarry sources, and admixture of other natural and synthetic materials can extend the range of decomposed granite properties.
Hoggin is a compactable groundcover that is composed of a mixture of clay, gravel, and sand or granite dust that produces a buff-coloured bound surface.
Paver base is a form of aggregate used in the construction of patios and walkways whose topmost layer consists of mortarless pavers. The first layer in the construction of such a surface is called the subgrade—this is the layer of native material underneath the intended surface. It is usually compacted and stabilized. If the final pavement is to have vehicle traffic, a layer of subbase of crushed stone or concrete must come next—this layer will even out the subgrade and will bear the heaviest load from the pavement above. Next comes the base course composed of crushed gravel varying from 0.75 in (1.9 cm) down to dust-particle size. It too is typically compacted and evened. The next layer will be the paver base, composed of coarse sand and typically between 6 and 12 in thick, depending on anticipated traffic.