AGGREGATE
DAVID GRUBBA
Theory
Aggregate
Theory
2. Types of
Aggregates
1. Introduction
1
Introduction
Water Cement
Sand*
Mortar Gravel**
CONCRETE STEEL
REINFORCED
CONCRETE
Aggregate
Mortar ≠ Concrete ≠ Reinforced Concrete
* Fine aggregate
** Coarse aggregate
AGGREGATE
Aggregates
MORTAR
BALLAST (RAILROADS)
2
Types
How is it made:
Crushed
Stone
Stone Drilling
Blasting
(explosives)
Load the
stone
Transport
Primary Crusher
Secondary Crusher
Tertiary Crusher
Screening
Different Sizes
Product
Handling
Production
(Photos)
Explosive Primary Crusher
First reduction in size
Secondary
Crusher
Crushed
Stone
Conveyor Belts
Load of stone
Dump Truck
First reduction in size
Different Sizes of
Crushed Stone
Photo: Mineração Santiago
Different Sizes of
Crushed Stone
Photo: Mineração Santiago
Different Sizes of
Crushed Stone
Photo: Mineração Santiago
Different Sizes of
Crushed Stone
Photo: Mineração Santiago
Sand
Expanded Clay
Common Tests
Aggregate
Properties
(Tests)
1. Size Classification
2. Shape Classification
3. Hardness (Los Angeles Test)
4. Moisture Content
5. Bulking of sand
1
Size
Classification
Aggregate: Sieves
Granulometry is the
measurement of
the size distribution
in a collection of
grains
Poorly
Graded
aggregate
Well-graded
aggregate
Different concretes
Which is
cheaper?
The coloured areas represent
Portland Cement Water Past
Photos
2,85 g
85,58 g
240,04 g
231,11 g
247,20 g
20,25 g
49,34 g
123,63 g
Example of sieve analysis
Sieve size
(mm)
Mass retained
(g)
Percentage
retained
Cumulative
Percentage
retained
Cumulative
Percentage
passing
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):
2
Shape Classification
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
To make concrete, which is
better:
Rounded or Flaky
aggregate
Photo: Cimentos Itambé
FlakyRounded
3
Hardness
Los Angeles Test
Sample of Aggregate
Steel balls
Retained
Sieve
Broken material
Los Angeles Test
RESULT: The proportion of broken
material, expressed as a
percentage
4
Moisture
Content
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
5
Bulking of Sand
Bulking of sand
Dry W = 3% W = 6%
The End

Aggregate - Concrete Technology