aggregate

Question 1

how many tonnes does ON consume of aggregate annually?

Answer 1

155 million

Question 2

name 6 uses of aggregate

Answer 2

• mulch
• septic field
• sports fields
• concrete products
• mortar
• joint sand for interlocking stone

Question 3

what are 5 sources of aggregates

Answer 3

1. gravel pit
2. quarry
3. slag and mine refuse
4. rubble and refuse
5. pulverized concrete and asphalt materials

Question 4

describe the aggregate extraction from a gravel pit process

Answer 4

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

Question 5

what is the ‘over burden’ referred to ?

Answer 5

layer of top and sub soil over top of the gravel

Question 6

describe 3 aggregate processing methods

Answer 6

crushing, screening and washing

Question 7

describe grade of aggregates

Answer 7

1. fill

2. sand fill

Question 8

what is fill

Answer 8

• not really an aggregate
• used for building up grade, under grass or backfilling holes or structures where drainage and structural strength are not issues

Question 9

what is sand fill

Answer 9

• sandy non specific material

- building up grade or backfilling where some drainage is required and no large stone sizes are desired

Question 10

what type of material comes from gravel pit aggregates?

Answer 10

-granite based

Question 11

describe 4 types of granite based aggregate?

Answer 11

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

Question 12

how are materials screened

Answer 12

• dumped into vibrating screen

Question 13

what is pit run ?

Answer 13

• free running stony gravel with well graded natural sand

- used for filling areas in wet conditions where product with more stone required (road base)

Question 14

describe 6 types of sand

Answer 14

1. septic: water retention qualities
2. golf course
3. sports field sand
4. ice control sand
5. brick sand
6. concrete sand

Question 15

describe 4 types of granite based screened products?

Answer 15

1. river rock 1”- 4”
2. pea stone 1/4”
3. roofing stone 1/2”- 1”
4. drain stone 3/4”- 2”

Question 16

why wash aggregate?

Answer 16

• separates sand from stone and removes impurities

- more $$

Question 17

what material is found in quarried aggregates?

Answer 17

limestone

Question 18

what 2 benefits from crushing stone?

Answer 18

1. reduced to workable size

2. jagged edges good for concrete and asphalt

Question 19

name 6 quarried aggregates

Answer 19

1. 3/4 crusher run: 100% crushed stone, chips and dust –> base where drainage isnt issue
2. 3/4 clear: 100% crushed stone, 3/4” in size–> good drainage material, behind retained walls
3. limestone screenings: 100% crushed stone, 1/4” - dust –> highly compactable with high water holding capacity, can be used as pathway
4. High Performance Bedding: 100% chipped stone 1/4” in size –> good draining material, falls at compaction rate, good base material for interlocking patio
5. crushed oversize: 4” and under to dust –> strong sub base
6. HL6 stone: clear crushed stone –> asphalt