aggregate Flashcards
(19 cards)
how many tonnes does ON consume of aggregate annually?
155 million
name 6 uses of aggregate
- mulch
- septic field
- sports fields
- concrete products
- mortar
- joint sand for interlocking stone
what are 5 sources of aggregates
- gravel pit
- quarry
- slag and mine refuse
- rubble and refuse
- pulverized concrete and asphalt materials
describe the aggregate extraction from a gravel pit process
- strip topsoil
- strip subsoil
- extract garvel
- but back the sub soil and topsoil for rehabilitation
ie stripping, extracting, processing, shipping, rehabilitation
what is the ‘over burden’ referred to ?
layer of top and sub soil over top of the gravel
describe 3 aggregate processing methods
crushing, screening and washing
describe grade of aggregates
- fill
2. sand fill
what is fill
- not really an aggregate
- used for building up grade, under grass or backfilling holes or structures where drainage and structural strength are not issues
what is sand fill
- sandy non specific material
- building up grade or backfilling where some drainage is required and no large stone sizes are desired
what type of material comes from gravel pit aggregates?
-granite based
describe 4 types of granite based aggregate?
- granular C: lower grade natural sand and stone sizes up to 6” –> covering sewer pipe or road sub base
- granular B: cleaner well- graded natural sand and stone 4” in size –> sub base for roadbuilding or under concrete floor slabs
- Fine Granular B: bank material screened to 2.5” for more uniform product and eliminate oversized stone –> base material and backfilling applications
- Granular A: well grade sand under 3/4” –> strength while maintaining good drainage , concrete
how are materials screened
- dumped into vibrating screen
what is pit run ?
- free running stony gravel with well graded natural sand
- used for filling areas in wet conditions where product with more stone required (road base)
describe 6 types of sand
- septic: water retention qualities
- golf course
- sports field sand
- ice control sand
- brick sand
- concrete sand
describe 4 types of granite based screened products?
- river rock 1”- 4”
- pea stone 1/4”
- roofing stone 1/2”- 1”
- drain stone 3/4”- 2”
why wash aggregate?
- separates sand from stone and removes impurities
- more $$
what material is found in quarried aggregates?
limestone
what 2 benefits from crushing stone?
- reduced to workable size
2. jagged edges good for concrete and asphalt
name 6 quarried aggregates
- 3/4 crusher run: 100% crushed stone, chips and dust –> base where drainage isnt issue
- 3/4 clear: 100% crushed stone, 3/4” in size–> good drainage material, behind retained walls
- limestone screenings: 100% crushed stone, 1/4” - dust –> highly compactable with high water holding capacity, can be used as pathway
- High Performance Bedding: 100% chipped stone 1/4” in size –> good draining material, falls at compaction rate, good base material for interlocking patio
- crushed oversize: 4” and under to dust –> strong sub base
- HL6 stone: clear crushed stone –> asphalt
