The Aggregates & Recycling Information Network

Glossary: W

  • Ward-Leonard Speed Control

    One of the most versatile methods of speed control of a dc motor. It involves the use of a separate motor generator set to supply a variable voltage to the armature of the machine under control. Used in controlling the speeds of the motors in large electrically operated shovels.

  • Washery

    A coal-preparation plant in which a cleaning process is carried out.

  • Waste Acceptance Criteria

    The criteria to be met before waste is accepted at a landfill site. There are different acceptance criteria for:

    • Inert waste
    • Non-hazardous waste
    • Hazardous waste.

    Each WAC may include:

    • a list of wastes not requiring a test
    • leaching limit values for contaminants
    • limit values for other parameters.

    Special provisions exist for certain wastes under certain conditions.

    abbr. WAC

  • Water Absorption

    An aggregate property which can be tested to indicate porosity and hence strength and likely resistance to weathering.

  • Water Coupling

    A means by which flushing water can be fed into a hollow drill rod or stem as it rotates. 

    Also: water swivel

  • Water Hammer

    A hammer-like blow caused by a sudden high pressure in a pipe when the flow is stopped by the closing of a valve too rapidly.

  • Water Resistance

    A qualitative measure of the ability of an explosive or blasting agent to withstand exposure to water without deteriorating or becoming desensitized.

  • Water Swivel

    A means by which flushing water can be fed into a hollow drill rod or stem as it rotates.

    Also: water coupling 

  • Water Table

    The upper limit or surface of the ground water or zone of permanent saturation. It may follow approximately the profile of the land surface.

  • Water/cement Ratio

    The ratio of the weight of water to the weight of cement in a concrete. The higher the water/cement ratio, the lower the compressive strength of the concrete.

  • Waterbound Macadam

    A form of road construction consisting of broken stone, slag or gravel, intimately interlocked and compacted in the presence of water, the binding agent being loam, sand, stone particles or the like.

  • Watt

    A rate of working of one joule per second, ie the work done by a force of one newton in moving through a distance of one metre in one second.

    Symbol: W

  • Wattmeter

    An instrument for measuring the power in an electrical circuit.

  • Wavelength

    The distance between corresponding points on two successive waves.

    Symbol: A

  • Wayleave

    A right in the nature of an easement granted for a limited period by a landdowner to another party.

  • Wearing Course

    Obsolete term for that part of the road surfacing which directly supports the traffic now described as surface course.

  • Weathering

    Changes in rocks which occur as the result of the action of rain, snow, hail, wind, heat and cold, exposure to air and other atmospheric and chemical processes.

  • Weber

    The magnetic flux which, linking a circuit of one turn, produces in it an electromotive force of one volt as it is reduced to zero at a uniform rate in one second.

    Symbol: Wb

  • Wedge-wire Screen

    A screen deck comprising wires of wedge-shaped cross-section spaced from each other at a fixed dimension; the underflow thus passes through an aperture of increasing cross-section.

  • Weight

    The force of gravity acting on a body at the Earth’s surface.

    Weight = mass x acceleration due to gravity.

    Units: newtons

  • Weight Strength

    The strength of an explosive per unit weight, expressed as a percentage of the value for blasting gelatine or ANFO as a standard.

  • Weighting

    Applying factors or weights to each of a number of observations in order to represent their relative significance in calculating for instance a weighted average.

  • Welding

    The heating of two metal surfaces until they melt and fuse together.

  • Wet Pit

    A sand and gravel excavation in land lying below the water table. Working may be by dragline excavator or pontoon-mounted pump etc.

  • Wet Suppression

    Dust control in processing operations by the use of water sprays into crushers, on to screens or conveyor belt transfer points.

  • Wet-mix Macadam

    A roadbase material consisting of graded crushed rock or slag usually premixed with a controlled amount of water sufficient for adequate compaction.

  • Whinstone

    A trade term describing a tough fine-to-medium grained igneous rock such as basalt, dolerite etc.

  • White Metal

    A tin-base alloy used for lining bearings.

  • Whole-circle Bearing

    Whole-circle bearings are measured clockwise from north, from 0° to 360°.

    See also: azimuth

  • Winding

    The insulated conductors which carry the current in an electric machine or transformer.

  • Winning

    The several operations involved in breaking the rock from the solid and loading it for transport to the treatment plant.

  • Winze

    A vertical or steeply inclined shaft which has been driven downwards.

  • Wire Drawing

    The process of reducing the diameter of rod or wire by passing it through a series of dies having successively smaller diameters.

  • Wireline Drilling

    A method of drilling using a wireline core barrel in which the drill rods remain in the hole and the core barrel is retrieved by an overshot lowered through the rods on the end of a wire line after the water swivel has been removed; this results in much time-saving when deep holes are drilled.

  • Work

    Work is done when a force is applied to a body and the body moves in the direction of the force.

    Unit: joule (J), equal to one newton-metre

  • Work Cycle

    The sequence of elements which is required to perform a task or to yield a unit of production. The sequence may sometimes include occasional elements. BS 42001.

  • Work Measurement

    The determination of the proper time to allow for the effective performance of a specific task. It is concerned with investigating, reducing and subsequently eliminating ineffective time, ie time during which no effective work is being performed.

    Also: time study 

  • Work Study

    Term for the techniques used in analysing the methods used in carrying out an operation and of measuring the work involved.

  • Workability

    Term used to describe the ease with which concrete can be compacted. Wet concretes are workable but weak. Workability can be measured by the slump test and the compacting factor test.

  • Working Capital

    The capital available to meet the day-to-day expenses of running the business. This is the excess of current assets (mainly trade debtors, stock, cash at bank and in hand) over current liabilities (mainly trade creditors and bank overdrafts).

  • Wound-rotor Motor

    An induction motor the ends of the rotor windings of which are connected to slip-rings through which external resistance may be added to the rotor circuit for starting purposes. Used for duties in which on-load starting is required.

    Also: slip-ring motor 

  • WRAP

    abbr. Waste & Resources Action Programme

    A not-for-profit company, backed by government funding, which helps individuals, businesses and local authorities to reduce waste and recycle more, making better use of resources and helping to tackle climate change.