Flashcards in aggregate Deck (19):
how many tonnes does ON consume of aggregate annually?
name 6 uses of aggregate
-joint sand for interlocking stone
what are 5 sources of aggregates
1. gravel pit
3. slag and mine refuse
4. rubble and refuse
5. pulverized concrete and asphalt materials
describe the aggregate extraction from a gravel pit process
1. strip topsoil
2. strip subsoil
3. extract garvel
4. 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
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?
describe 4 types of granite based aggregate?
1. granular C: lower grade natural sand and stone sizes up to 6" --> covering sewer pipe or road sub base
2. granular B: cleaner well- graded natural sand and stone 4" in size --> sub base for roadbuilding or under concrete floor slabs
3. Fine Granular B: bank material screened to 2.5" for more uniform product and eliminate oversized stone --> base material and backfilling applications
4. 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
1. septic: water retention qualities
2. golf course
3. sports field sand
4. ice control sand
5. brick sand
describe 4 types of granite based screened products?
1. river rock 1"- 4"
2. pea stone 1/4"
3. roofing stone 1/2"- 1"
4. drain stone 3/4"- 2"
why wash aggregate?
-separates sand from stone and removes impurities
what material is found in quarried aggregates?
what 2 benefits from crushing stone?
1. reduced to workable size
2. jagged edges good for concrete and asphalt