Aggregate Glossary

AASHTO
American Association of State Highway and Transportation Officials
Absorption
The penetration of liquid into aggregate particles with a increase in particle weight.
AREA
American Railway Engineering Association
Armor Stone
2 to 8 ton boulders used to construct jetties to prevent erosion due to the action of large waves.
Asphaltic Concrete
A mixture of coarse aggregate, fine aggregate, liquid asphalt and possibly other additives that when mixed in a Hot Plant and properly placed and compacted at the jobsite, provide a hard and durable flexible pavement.
ASTM
American Society for Testing and Materials
Baserock
Aggregate Base is a well-graded aggregate suitable for compacting to such a degree that it provides a firm, stable base. Project specifications determine what class of aggregate base will be used.
CBR (California Bearing Ratio)
Used to characterize the strength of an unbound aggregate base
Chipseal
An application of a clean sized-aggregate which is applied to a freshly spread layer of asphalt emulsion
Cleanness Value
An indication of the clay-sized material clinging to coarse aggregate
Coarse Aggregate
Generally considered to be aggregate that is larger than the #4.
Crushed Aggregates
Any hard, sound rock that is produced by blasting and then crushing. The aggregate is then screened to a specific size.
Degradation
The breakdown into smaller pieces of an aggregate when subjected to applied forces such as those produces by mixer blades, compaction, heavy wheeled loads, and grinding action.
Deleterious Materials
Those substances present in an aggregate that are harmful to the desired properties of an aggregate-binder system.
Drainage Blanket
A layer of aggregate that allows the passage of water
Drain Rock
A clean durable aggregate that when in place allows the flow of water.
Durability
The resistance of aggregate particles to the accumulative effects of environmental and cyclical load conditions. Lack of aggregate durability results leads to a breakdown of aggregate particles resulting in an alteration in gradation and impairment of performance.
End Result Specifications
The type of specifications written to focus on finished product compliance with project specifications.
Filter Fabric
Fabric used to prevent the migration of fines from one layer to another.
Fine Aggregate
Generally considered to be any material that passed the 3⁄8″ sieve, and essentially all passes the #4 sieve and is predominantly retained on the #200 sieve.
Fog Seal
A very light application of diluted asphaltic emulsion, generally applied without an aggregate cover, to enrich and seal the surface of a bituminous pavement.
Gabion
3″ to 10″ stone used to fill galvanized, a woven steel wire basket that is used for erosion control and retaining wall construction.
Gradation
The distribution of different particles of aggregate by size.
GraniteFax
A service offered by Graniterock allowing customers to request information to be faxed directly to their place of business.
GraniteXpress
An automated state-of-the-art aggregate loadout system used at the A.R. Wilson Quarry (Aromas) that allows customers trucks to be loaded 24 hours a day, 7 days a week
Interlock
The characteristic of a crushed angular aggregate to key into adjacent angular aggregates that provides superior strength and load-carrying capabilities.
LA Rattler
Los Angeles Degradation Test (AASHTO T-96 — ASTM C 131) is the most widely specified test for the evaluation of the resistance of a coarse aggregate to degradation by abrasion and impact.
Liquid Limit
The water content at which the minus #40 size fraction passes from a plastic to a liquid state.
Maximum Particle Size
The minimum size screen opening through which 100% of the material will pass.
MSHA
Mine Safety & Health Administration (Federal)
Overburden
Rock, soil, or loose debris that is above the mineable aggregate resource and is of insufficient quality to process into construction grade aggregate.
Paint Binder (Caltrans)
See Tack Coat
Particle Shape
The shape of the individual aggregate particle.
Particle Strength
The magnitude of tensile and/or compressive stress that an individual aggregate particle can withstand before failure occurs
Particle Surface Texture
The degree of roughness or irregularity of the surface of an aggregate particle.
Paving Fabric
A fabric used on an asphalt pavement overlay that when properly installed will prevent the cracks present in the original asphalt layer from transferring to the new pavement section.
Pea Gravel
A clean rounded aggregate usually ¼″ or 3⁄8″ typically used in drainage applications or in PCC
Permeability
The capacity of an aggregate particle, or group of particles, to transmit a fluid.
Pitting
The disintegration of weak, friable pieces of aggregate due to frost action.
Plasticity Index
The difference between the Liquid and Plastic Limit
Plastic Limit
The lowest water content at which the minus #40 fraction remains cohesive enough to hold together when rolled with the fingers on a glass plate or sheet of unglazed paper into a thread 1⁄8″ in diameter.
Porosity
The percentage of the total volume of an aggregate partivle occupied by pore spaces.
Portland Cement Concrete
A mixture of hydraulic cement, coarse aggregate, fine aggregate, water, and possibly admixtures when properly mixed and allowed to properly hydrate provide a strong, hard structural building material.
Prime Coats
An application of a low viscosity asphalt emulsion (generally diluted) or cutback asphalt to a native soil or aggregate base surface; the purpose being to bind the surface and to provide a bond between the surface and another bituminous layer to follow.
Quality Control
The process of controlling the quality of the aggregate and encompasses the processing plant design, the techniques implemented in processing, materials handling, stockpiling, and loadout.
Quality Assurance
The dependable and accurate monitoring and documentation process to assure that the products shipped do indeed meet aggregate specifications.
Rail Ballast
A clean, hard coarse aggregate that provides the uppermost layer in a railroad track structure and is located immediately beneath and surrounding the ties.
Reactive Aggregate
An aggregate that has components that interact with the binder resulting in deleterious expansion of the mixture.
Resistance Value (R Value)
A test method to determine the Resistance to Lateral Deformation
RipRap
Large stone used to stabilize slopes and shorelines, to construct erosion control structures, and also in building construction and landscaping.
Strategic Highway Research Program (SHRP)
$150 million research program funded by the federal government to improve highway construction practices and products.
Sampling
The process of attaining a random and representative specified volume of an aggregate for testing.
Sand & Gravel
Any clean, unconsolidated mixture of fine and/or coarse aggregate found in a natural deposit. Most sand & gravel deposits are formed by deposition of water.
Sand Equivalent Test (SE)
A rapid field-correlation test to indicate the relative proportion of plastic fines and dust to sand size particles in granular soil and fine aggregate that pass the #4 sieve.
Segregation
The separation of one size of particles from a mass of particles of different sizes.
Shrinkage
The property of the mortar in Portland Cement Concrete that undergoes shrinkage as it dries as a result of hydration and evaporation.
Skid Resistance
The property of a paved surface that provides a resistance to skidding.
Sodium Soundness Test
A test process used to determine the freeze-thaw characteristics of an aggregate.
Solubility
The tendency of an aggregate to be dissolved by a liquid
Special Provisions
The section of a Project Bid Document that addresses special specifications that bidders must adhere to in submitting their bid documents.
Specific Gravity
The ratio of the mass of a given volume of aggregate to the mass of an equal volume of water.
Stability
The property which permits a combination of aggregate particles to remain stable and retain their load-carrying capabilities under various types of loading
Stripping
The loss of adhesion between asphalt and aggregate due to moisture sensitivity.
Tack Coat
A light spray application of low viscosity asphalt emulsion (generally diluted) to an existing pavement surface to insure a bond between the original pavement and a subsequent asphalt concrete overlay
Toughness
The resistance to fracture from impact. It is closely related to the absence of brittleness.
TransloadXpress
A mobile railcar unloading system developed and constructed by Graniterock to unload bottom discharge railcars and transport the flowable product to either stockpile, conveyor belt, or truck bed.
Voids in Aggregate Mixture
The spaces between aggregate particles

For more information on aggregates and their uses or to schedule a Quarry Tour or Seminar please contact Graniterock Aggregates Sales at 831.768.2380.