Concrete Waterproofing Glossary
Ganged Forms
prefabricated panels joined to make a much larger unit (up to 30 by 50 ft) (9 by 15 m) for convenience in erecting, stripping, and reusing; usually braced with wales, strongbacks, or special lifting hardware.
Gap-graded Aggregate
aggregate graded so that portions of aggregate retained on specifiedintermediate sieves is substantially absent.
Gehlenite
a mineral of the melilite group, Ca 2 Al(AlSi) O 7 . (See also melilite andmerwinite.)
Gillmore Needle
a device used in determining time of setting of hydraulic cement.
Go-devil
(1) a ball of rolled-up burlap or paper or a specially fabricated deviceput into the pump end of a pipeline and forced through the pipe by waterpressure to clean the pipeline;
(2) a device used with tremie concreteoperations.
Grade
(1) the prepared surface on which a concrete slab is cast;
(2) the processof preparing a plane surface of granular material or soil on which to cast a concrete slab.
Grade Beam
a reinforced-concrete beam, usually at ground level, that strengthens or stiffens the foundation or supports overlying construction.
Grade Strip
usually a thin strip of wood tacked to the inside surface of forms at the elevation to which the top of the concrete lift is to rise, either at a construction joint or the top of the structure.
Gradient
rate of change in a variable over a distance.
Grading
the distribution of particles of granular material among various sizes.
Grading Curve
a graphical representation of the proportions of different particle sizesin a granular material, obtained by plotting the cumulative or individual percentages of the material passing through sieves in which the aperture sizes form a given series.
Granolithic Concrete
concrete suitable for use as a wearing surface finish to floors, made with specially selected aggregate of suitable hardness, surface texture, and particle shape.
Granolithic Finish
a surface layer of granolithic concrete that may be laid on a base of either fresh or hardened concrete.
Gravel
aggregate retained on the 4.75 mm (No. 4) sieve and resulting either from natural disintegration and abrasion of rock or processing of weakly bound conglomerate. (See also coarse aggregate.)
Green Concrete
concrete that has undergone final setting but not hardened appreciably.
Grid Foundation
a combined footing formed by intersecting continuous footings, loaded at the intersection points, and covering much of the total area within the outer limits of the assembly.
Grinding Aids
materials used to expedite the process of grinding by eliminating ballcoating, dispersing the finely ground product, or both.
Grinding Medium
a hard, free-moving charge in a ball or tube mill to reduce the particle size of introduced materials by attrition or impact.
Grizzly
a simple, stationary screen or series of equally spaced parallel bars set at an angle to remove oversized particles in processing aggregate or other material.
Grog
burned refractory material, usually calcined clay or crushed brick bats.
Groover
a tool used to form grooves or weakened-plane joints in a concrete slabbefore final setting to control crack location or provide pattern.
Ground Wire
small-gauge high-strength steel wire used to establish line and grade as in shotcrete work (also called alignment wire and screed wire).
Grout
mixture of cementitious materials and water, or other binding medium,with fine aggregate. (See also neat cement grout and sanded grout.)
Grout Slope
the natural slope of fluid grout injected into preplaced-aggregate concrete.
Grouted Masonry
unit masonry composed of either hollow units wherein the cells are filled with grout or multiple wythes where spaces between the wythes are filled with grout.
Grouting
the process of filling with grout. (See also grout.)
Gun
(1) shotcrete material delivery equipment;
(2) pressure cylinder used to propel freshly mixed concrete pneumatically.
Gun Finish
undisturbed final layer of shotcrete as applied from nozzle without hand finishing.
Gunite
a proprietary term for shotcrete.
Gunman
workman on shotcreting crew who operates delivery equipment.
Gunning
the act of applying dry-mix shotcrete.