Lesson: Concrete Technology - Building Materials The quality of aggregate affect the durability and strength of concrete. Since about 3/4 of the volume of concrete is occupied by aggregate.

1. AGGREGATE
DAVID GRUBBA

2. Theory

3. Aggregate
Theory
2. Types of
Aggregates
1. Introduction

4. 1
Introduction

5. Water Cement
Sand*
Mortar Gravel**
CONCRETE STEEL
REINFORCED
CONCRETE
Aggregate
Mortar ≠ Concrete ≠ Reinforced Concrete
* Fine aggregate
** Coarse aggregate

7. AGGREGATE
Aggregates

9. MORTAR

13. BALLAST (RAILROADS)

14. 2
Types

16. How is it made:
Crushed
Stone

18. Stone Drilling
Blasting
(explosives)
Load the
stone
Transport
Primary Crusher
Secondary Crusher
Tertiary Crusher
Screening
Different Sizes
Product
Handling

19. Production
(Photos)
Explosive Primary Crusher
First reduction in size
Secondary
Crusher
Crushed
Stone
Conveyor Belts

22. Load of stone

23. Dump Truck

25. First reduction in size

26. Different Sizes of
Crushed Stone
Photo: Mineração Santiago

27. Different Sizes of
Crushed Stone
Photo: Mineração Santiago

28. Different Sizes of
Crushed Stone
Photo: Mineração Santiago

29. Different Sizes of
Crushed Stone
Photo: Mineração Santiago

31. Sand

34. Expanded Clay

35. Common Tests

36. Aggregate
Properties
(Tests)
1. Size Classification
2. Shape Classification
3. Hardness (Los Angeles Test)
4. Moisture Content
5. Bulking of sand

37. 1
Size
Classification

38. Aggregate: Sieves

40. Granulometry is the
measurement of
the size distribution
in a collection of
grains

41. Poorly
Graded
aggregate
Well-graded
aggregate
Different concretes
Which is
cheaper?
The coloured areas represent
Portland Cement Water Past

42. Photos

50. 2,85 g
85,58 g
240,04 g
231,11 g
247,20 g
20,25 g
49,34 g
123,63 g

51. Example of sieve analysis
Sieve size
(mm)
Mass retained
(g)
Percentage
retained
Cumulative
Percentage
retained
Cumulative
Percentage
passing

53. Sieve
Percentage
Retained
Cumulative
Percentage
Retained
4,8 0 % 0%
2,4 0 % 0 %
1,2 0 % 0 %
0,6 40 % 40 %
0,3 30% 70 %
0,15 30% 100 %
Sum 210
FM 2,1
Fineness Modulus
Fineness Modulus (FM): defined as the sum of the cumulative percentages
retained on the sieves of the standard series, divided by 100.
Sieve
Percentage
Retained
Cumulative
Percentage
Retained
4,8 20 % 20 %
2,4 30 % 50 %
1,2 50% 100 %
0,6 0 % 100 %
0,3 0 % 100 %
0,15 0% 100 %
Sum 470
FM 4,7
Example (Aggregate 2):Example (Aggregate 1):

54. 2
Shape Classification

55. Rounded
Angular
Flaky
Shape
Completely shaped by attrition
Possessing well-defined edges
Aggregate of which the thickness is small
relative to the other two dimensions

56. To make concrete, which is
better:
Rounded or Flaky
aggregate

57. Photo: Cimentos Itambé
FlakyRounded

58. 3
Hardness
Los Angeles Test

60. Sample of Aggregate
Steel balls
Retained
Sieve
Broken material
Los Angeles Test
RESULT: The proportion of broken
material, expressed as a
percentage

61. 4
Moisture
Content

63. Moisture Content
MC = W- D x 100%
W
W = wet weight
D = weight after drying
The are various
methods for
measuring the
moisture content of
aggregate

64. 5
Bulking of Sand

65. Bulking of sand
Dry W = 3% W = 6%

66. The End