Page 322 - directory final 2014/2015

Freight Forwarding

VENT SYSTEM – In plumbing, a system to provide a flow of air to or from a drainage system or to provide circulation of air

within such system to protect traps seals from siphonage and back pressure.

VERMICULITE - An aggregate somewhat similar to perlite that is used as an aggregate in lightweight roof decks and deck

fills. It is formed from mica, a hydrous silicate.

VISCOSITY - The internal frictional resistance offered by a fluid to change of shape or to the relative motion or flow of its

parts.

VISIBLE LIGHT TRANSMITTANCE – The percentage of visible light (390 to 770) nanometers) within the solar spectrum

that is transmitted through glass.

VISUAL MOCK UP – Small scale demonstration of a finished construction product.

VOLTAGE - The driving force behind the flow of electricity somewhat like pressure is in a water pipe.

VOLTMETER - measures the voltage flowing through a circuit. The circuit must be closed to allow the voltage to flow.

W

WALKWAYS - Designated areas for foot traffic.

WATER-CEMENT RATIO - The strength of a concrete mixture depends on the water cement ratio. The water and cement

form a paste. If the paste is made with more water, the concrete becomes weaker. Traditionally, concrete mixes have been 321

identified in terms of the ratio of cement to fine aggregate to coarse aggregate. For example, the ratio 1:2:4 refers to a mix

which consists of 1 cu. ft. of cement, 2 cu. ft. of sand and 4 cu. ft. of gravel. Cement and water are the two chemically active

elements in concrete and when combined, form a paste or glue which coats and surrounds the particles of aggregate and upon

hardening binds the entire mass together.

See page 326

Service Providers Chamber of Construction Industry Sri Lanka