Glossary of Paving Terminology
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Absorption: When a weight of water is permeated or soaked into a paver unit. Often referred to as a ‘rate of absorption’ or as a percentage.
Aggregate: Used for base materials and mixed in with cement to make concrete, it usually consists of crushed stone, gravel and sand.
Angularity: Describes the shapes and sharpe edges of the aggregate and sand consistency, used for base materials.
Armortec: top layer of Cambridge Pavers, consists of high-density concrete, sand granules and extra color, forming a very versatile paver.
Aspect Ratio: The length of a paver unit divided by the thickness of the paver unit.
Asphalt: a highly viscous liquid that naturally occurs in crude petroleum.
Aquifer: Yields water for consumption, a porous formation.
Base or Base Material: A layer of aggregate, of particular thickness, to suite the installation requirements. It is laid after your sub-base has been prepared, and before your sand bedding is implemented. It provides support to the sand and pavers, particularly when compacted intensely.
Bedding Sand: This layer contains coarsely-grained sand, which provides a setting bed for paver units. The sand bedding is always leveled, for a smooth surface.
Bitumen: Can be used as an adhesive under pavers. Made from a combination of asphalts and neoprene.
Blending Pavers: Applying the use of two or more colored pavers.
Bluestone: is a type of rock known as dolerite, it appears blue when wet or broken.
Brick Paver: blocks made of shale and clay, which are kiln-fired and manufactured in molds.
Bulge or Belly: This occurs in concrete pavers, where there has been to much water mixed into the concrete mix, resulting in convex sides.
Bundle: Refers to a stack or load of pavers, wrapped and strapped for shipment.
Cantera Stone: a natural stone, quarried in Mexico.
Cation: When the metal ions in storm water runoff attach themselves to soil particles, which become positively charged atoms.
Cement-Aggregate Ratio: The weight ratio of cement and aggregate in concrete.
Chamfer: A beveled edged paver, which allows water drainage, snow removal and reduces the occurrence of chipping pavers.
Clay: The putty-like portion of soil particles that when watered and air-dried, can exhibit a strong plastic-like nature.
Cobblestone: stones taken from riverbeds and used to pave early streets.
Compaction: The use of a piece of equipment to intensely pack soil, base material and sand bedding. Often using a powered tamper or plate compactor.
Compressive Strength: The measured resistance of pavers to loads, referred to in pounds per square inch, and newtons per square millimeter.
Concrete: made from cement binder and aggregate, it then hydrates and hardens into the stone surface. The traditional term for concrete was ‘liquid stone’.
Concrete Pavers: Paving units made from concrete, available in a variety of sizes and shapes, and can be laid in many patterns and designs.
Concrete Sand This is a type of washed sand, quite coarse, used for aggregates and bedding sands.
Course: A row of pavers.
Creep: Refers to the slow shifting of paver units over a long period of time.
Crushed Stone: Often used as an aggregate and as the base material for laying pavers. Commonly used for their sharp edged consistency, making compaction so much easier.
Deformation: When the shape and structure of a pavement is altered.
Degradation Testing: Testing for changes in particle sizes, of aggregates and sand, due to the impact of loads over a period of time.
Denated Paver: a paver that is not rectangular or square in shape.
Density: for every unit of volume the mass is measured.
Drainage Coefficient: Measures how well a pavement will filtrate masses of water.
Dry Mix Joint Sand Stabilizer: This is a chemical treatment for joint sand, which enables them to stabilize when overflowed with water, prevent weed growth and reduce its permeability.
Edge Paver: Can be bought ready made with a straight side or can be cut straight.
Edge Restraint: An edging that provides support and holds pavers in place, can be hidden or exposed.
Efflorescence: The white hazy discharge, consisting of calcium carbonate. It appears on the surface of your pavements, it is a natural occurrence, reacting to the materials used in the pavement. It can disappear over time, or there are cleaning products that will help to eliminate the problem.
Engraved Pavers: Pavers that are engraved with names, messages, images and logos, with the use of stencils and metal plates or have been manufactured to order.
Erosion: The process of wearing rocks, sands, soils, through the effects of water, wind, ice and gravity. The displacement of solids.
Exfiltration: When water is allowed movement through the base material and into the soil underneath.
Fines: very fine silt and clay particles found in soil.
Finished Grade: Or finished elevation refers to the final elevation of the base, soil or pavement.
Flagstone: a type of flat stone used for paving, roofing and building.
Flash: Or Flange, a thin layer of cement around the edges of a paver, due to leakage between the elements of the molds.
Flexible Pavement: A pavement that maintains and allows for the distribution of loads to the subgrade.
Freeze-Thaw Durability: Depicts how well pavers stand up to freeze-thaw cycles, water saturation and salt filtration.
Frost Action: the effects of freeze-thaw conditions on pavers.
Frost Heave: The lifting up of pavers due to the effects of ice, accumulation and expansion.
Geotextiles: Made from woven and unwoven plastic fibers, and used for the separation and protection and drainage between the layers of paved surfaces.
Gradation: Specified particle sizes of sand, soil and aggregate, distributed by mass.
Grade: (noun) usually expressed in percentages, it is the slope of a finished surface; (verb) is to finish off the surface with a piece of equipment or by hand.
Granite: a very hard, granular, crystalline, igneous rock, formed at great depths and pressures, consisting mainly of quartz, mica, and feldspar and often used as a building stone.
Gravel: The by product of eroded riverbed rocks, gravel is a culmination of very fine grained particles of rock, sometimes referred to as a type of soil.
Infiltration Rate: Usually measured in inches per hour or meters per second, it is the rate at which water filters through the soil.
Interlock: The inability of pavers to move independently. When pavers are interlocked, there is frictional forces between them, which prevent them from moving alone. Interlocking allows the bearing of heavy loads to be dispersed throughout the pavement.
Interlocking Pavement: A system of paving, where each paver unit is laid in an interlocking pattern, compacted; the joints filled with sand, and then compacted again to start interlock.
Joint Filling Sand: the process where sand is used to fill spaces between the pavers.
Joint Sand Stabilizer: A liquid solution that promotes joint sand stabilization, and prevents weeds growing, loosing sand and reduces the permeability of the joint sand.
Joint Sand: Sand that is swept into the openings between the pavers to fill up the joints.
Joint Spacing: The distance between the sides of the pavers.
K-pattern: A paving pattern with one square unit surrounded by rectangular units.
Laying Pattern: The sequence in which the pavers are installed, creating a geometric pattern. There are many patterns available to choose from.
Lift: A layer of compacted soil fill or aggregate.
Limestone: a sedimentary rock, composed of the mineral calcite, formed through the decomposition of marine organisms.
Mechanical Installation: When pavers are laid with the use of machinery, this method increases the rate of paving.
Modulus of Elasticity or Elastic Modulus: The measurement of the ratio of stress to strain on a material, due to load conditions.
Mexican Paver: hand made clay pavers.
Moisture Content: The weighed percentage of water contained in the pores of the soil, base and sand.
Mortar: A combined mix containing cement paste and fine aggregate (sand).
Mortar Sand: Sand used in mortar.
Mosaics: When pavers are used to create maps, murals or patterns to emphasize and area.
Multi-Colored Paver (Color Blend): A paver that has a combination of two or more colors.
Open-graded Aggregate Base: This type of aggregate has large spaces between particles, making it ideal for use as a drainage course.
Organic Soil: Spongy soils, usually made from vegetative matter, and are not suitable for construction use.
Outlet: where water is dispersed from an open-graded base through pipes into a storm sewer system.
Pavement Rehabilitation: Includes any work undertaken to improve and pro-long the life of a pavement, such as; removing and replacing.
Pavement Structure: The implementation of a sub base, base and surface material, to accommodate the needs of traffic and load bearings.
Paver Extractor: A tool used to pick a paver and remove it from the surface.
Paver Splitter: Used for the cutting of pavers, may be hand operated or machine operated, and is sometimes hydraulically assisted.
Performance Period: The time period for which a pavement should last, before needing service, usually measured in years.
Permeability: The rate at which water passes through the soil, usually measured in a laboratory.
Permeable Interlocking Pavement: A pavement system where a grid-like structure is installed, then vegetation is planted in the openings, which allows the infiltration, storage and drainage of runoff water.
Pervious or Permeable Surfaces: those that allow the infiltration of rainfall, such as; vegetated covered areas.
Plate Compactor: Used to compact soils, base materials, sand beddings and pavers, to promote interlocking. Otherwise known as a plate vibrator.
Porosity: The total volume of the base divided by the volume of voids in the base.
Porphyry Pavers: an igneous rock, varying in color, consists of large grained crystals.
Precast Concrete Pavers: manufactured paving stones, made from sand, gravel, pebbles and cement.
Progressive Stiffening: The occurrence of stiffening of a pavement over time, due to increases in traffic and loads.
Rubber Pavers: manufactured pavers made from 100% recycled tire rubber.
Running or Stretcher Bond: A type of laying pattern for pavers, where there are continuous joint lines in one direction, and then four pavers staggered from one row onwards.
Rutting: The result of repetitive traffic use and load bearing. Faults occur due to exceeding pavements capacity.
Sand Spreaders: A motorized attachment for brooms, used to spread sand over joints of paved surfaces.
Sandstone: a sedimentary rock, comprising of feldspar and quartz particles.
Screeding: The action of leveling a sand bedding, using wood or metal pieces to assist.
Screenings: A residual product, usually a by-product of crushed; rock, cobble, gravel or concrete. Not suitable for the sand bedding.
Sealer: A liquid solution which coats and protects your pavers and pavements. Sealers help with waterproofing, color enhancing and stain removal.
Sediment: Any sediment, such as soil, that is transported and deposited due to the effects of water, wind, gravity and ice.
Shrinkage: When the volume of soil is reduced due to the reduction in water content.
Silt: Extremely fine soil.
Skid Resistance: Measuring the friction of a surface exposed to rubber tires.
Slate: a finely grained, sedimentary rock, consisting of clay or volcanic ash, which has been foliated into layers.
Slip Resistance: The measurement of the resistance of a surface to users slipping and sliding over the surface.
Soil Separation Fabric: See geotextile.
Soil Stabilization: Treatments to increase the stabilization of a mass of soil. Can be chemically treated, or mechanically treated with the use of geogrids and geotextiles.
Solid Color Paver: By adding iron oxide or metal oxide pigments to a concrete mix, a paver with one color is created.
Spall: As a result of weather or pressure, pavers may chip and fragment.
Stained Concrete: when concrete is color stained to create vibrant colored finishes.
Stamped Concrete: concrete that has been stamped with a pattern.
Standing Screed: An aluminum screed with handles, which allows the person to pull it across the sand bedding, whilst standing up.
Stenciled Concrete: concrete is made to simulate other paving materials through the implementation of stencils.
Stone Pavers: see Limestone, Granite, Bluestone, and Sandstone.
Sub-base Commonly made from stone pieces, larger than that in the base materials. It is a layer of particular thickness, placed on a subgrade, giving support to the base material.
Subgrade: The soil base, which the pavement structure is constructed upon.
Topsoil: The surface soil, normally containing organic matter.
Travertine: a natural stone, it is white and is a form of calcium carbonate and is very hard in texture.