Aggregates

Aggregate Types:
Sand and gravel
Crushed stone - Sharp edges
River Stone -Cobble - - Smooth edges
Pea stone - Small river stone
Decorative Stone - Large stone for landscaping
Boulders
See Construction Aggregates – Stone, Sand and Gravel – Todd's Redi-MixTodds Redi Mix
and Affordable Garden Path Ideas | The Family Handyman

Size - grading:
Some Common sizes:
MD #2 / AASHTO #3 Stone: 2 - 2 1/2"
MD #5 = 1 - 1 1/2"
MD #8 = 3/8 - 1/2"
MD #10 Stone Dust Fines/dust with up to 1/4"
ASTM #57 Stone 1 to 1-1/2"
CR-6 up to 1 1/2"
CR-8 - 1" minus crusher run. Commonly referred to as "Site pack" or "Quarry Process Stone" or "Road Base"
See Aggregrate Gradation Chart
Source: Project Planning and Estimating Resources | The Stone Store

Density:

Terms:

AASHTO - American Association of State Highway and Transportation Officials
ASTM International, formerly known as American Society for Testing and Materials, is an international standards organization that develops and publishes voluntary consensus technical standards for a wide range of materials, products, systems, and services.
See Wikipedia and www.astm.org.
CR - Crushed Rock ?
California bearing ratio (CBR) test is a penetration test for evaluation of the mechanical behavior of road base and subbase course layers.
Graded aggregate base (GAB)
MD: Micro deval test Maryland
MD - A grading system for aggregates e.g. MD #1 = 3 1/2 - 4"; #2 - 2 - 2 1/2"; MD #8 = 3/8 - 1/2"
In soil mechanics, the void ratio describes the relationship between the volume of voids, or spaces, in the soil or aggregate to the volume of solid constituents, or grains. Algebraically, e = Vv /Vs, where e represents the void ratio, Vv represents the volume of voids and Vs represent the volume of solid grains.
Low density sand typically has a void ratio of about 0.8, while high density sand with angular particles typically has a void ratio about 0.4
Gravel typically has a void ratio about 0.4, regardless of whether it is well or poorly graded.
See: Void Ratio | Sciencing.com
MDOT SHA - Maryland Department of Transportation State Highway Administration
See Glossary of Terms

Links:
Construction Aggregates – Stone, Sand and Gravel – Todd's Redi-MixTodds Redi Mix
Aggregate Sizing Explained
Project Planning and Estimating Resources | The Stone Store
Crushed Stone Examples | paxcos.com
Development Of Design Guidelines For Proper Selection Of Graded Aggregate Base In Maryland State Highways

last updated 10 Oct 2018