GROUP 7 - AGGREGATES Flashcards
Science has divided rocks into three categories. What are these?
Igneous, Sedimentary, and Metamorphic Rocks
The very primary form of a rock formation is
from streams of magma that erupted from
volcanoes.
Igneous Rocks
These rocks are always formed from
the eroding of different pure mineral rocks.
Sedimentary Rocks
Means “change in the form or nature”
They are usually igneous or sedimentary
rocks that have changed their properties
greatly
Metamorphic Rocks
Natural solid masses or
aggregates of minerals
classified based on mineral
composition, texture, and
other physical features.
Stones
Sand is a granular substance
that occurs naturally and is
made up of finely split rock and
mineral particles.
Sand
WHY IS THERE A NEED TO KNOW CONSTITUENTS IN
AGGREGATES?
- Aggregate materials help to make concrete mixes more compact.
- Decrease the consumption of cement and water and contribute to the mechanical strength of the concrete.
Plutonic Rocks
medium- to coarse grained, light colored rock characterized
by the presence of potassium feldspar with lesser amounts of plagioclase feldspars and quartz.
Granite
Plutonic Rocks
syenite is a medium - to
coarse-grained, light colored rock
composed essentially of alkali feldspars,
namely microcline, orthoclase, or albite.
Syenite
EXTRUSIVE IGNEOUS ROCKS
volcanic or extrusive
rocks are fine-grained equivalents of the coarse-and-medium-grained plutonic rocks. Equivalent types have similar chemical compositions and may contain the same minerals
Volcanic Rock
EXTRUSIVE IGNEOUS ROCKS
fine-grained extrusive
equivalent of gabbro and diabase.
Basalt
SEDIMENTARY ROCKS
Conglomerates, Sandstones, and Quartzites
Gray to greenish gray sandstones containing
angular quartz and feldspar grains
Graywackes and subgraywackes
SEDIMENTARY ROCKS
Carbonate Rocks
The most widespread of carbonate rocks.
Limestone
SEDIMENTARY ROCKS
Conglomerates, Sandstones, and Quartzites
Coarse-grained sandstone
derived from granite, containing
conspicuous amounts of feldspar
Arkose
METAMORPHIC ROCKS
A recrystallized medium to coarse-grained carbonate rock
composed of calcite or dolomite, or calcite and dolomite
Marble
METAMORPHIC ROCKS
A granular rock consisting essentially of recrystallized quartz
Metaquartzite
METAMORPHIC ROCKS
A fine-grained metamorphic rock that is distinctly laminated and tends to split into thin parallel layers
Slate
CONSTITUENTS OF ARTIFICIAL AGGREGATE
The agglomerated residue from combustion of coal or coke
in an industrial furnace.
Cinders
CONSTITUENTS OF ARTIFICIAL AGGREGATE
The nonmetallic product, consisting essentially of silicates and aluminosilicates of calcium and other bases, that is developed in a molten condition simultaneously with iron in a blast furnace
Blast-furnace slag
The process by which a liquid is drawn into and tends to fill permeable pores in a porous solid body
Absorption
A material other than water, aggregates, hydraulic cement that is used as an ingredient
Admixtures
Granular material, such as sand, gravel, crushed stone, or iron blast-furnace slag, used with a cementing medium to form hydraulic-cement concrete or mortar
Aggregate
The mass of a unit volume of bulk aggregate material (the unit volume includes the volume of the individual particles and the volume of the voids between the particles)
Bulk Density
A particle of aggregate for which the ratio of the length to width of its circumscribing rectangular prism is greater than a specified value
Elongated Piece (of aggregate)
A particle of aggregate for which the ratio of the width to thickness of its circumscribing rectangular prism is greater than a specified value
Flat Piece (of aggregate)
An index of the fineness of the aggregate. The higher the FM, the coarser the aggregate. Fineness Modulus of fine aggregate is useful in estimating proportions of fine and coarse aggregate in concrete mixtures
Fineness Modulus
Finely divided residue that results from the process of combustion of ground or powdered coal and that is transported by flue gases
Fly Ash
A cementitious mixture, with or without aggregate or admixtures, that is used primarily to fill voids
Grout
In specifications for aggregate, the smallest sieve opening through which the entire amount of aggregate is required to pass.
Maximum size, n—of aggregate
The smallest sieve size through which the major portion of aggregate must pass (90%-100%)
Nominal maximum size of an aggregate
Coarse aggregate resulting from natural disintegration and abrasion of rock or processing of weakly bound conglomerate
Gravel
Fine aggregate resulting from natural disintegration and abrasion of rock or processing of completely friable sandstone
Sand
Refer to irregular and granular materials such as sand, gravel, or crushed stone, and are used for making concrete.
Retained on no. 4 sieve
Coarse Aggregates
Essentially any natural sand particles won from the land through the mining process.
Passing the no. 4 sieve
Fine Aggregates
Used for foundations and concretes and in products made of reinforced concrete and in road construction.
Gravel Aggregates
Granular loose material that acts as a skeleton or filling in
concrete.
Sand Aggregates
Granular loose material that acts as a skeleton or filling in
concrete.
Sand Aggregates
What are the two sources of aggregates?
Underwater Sources and Land Sources
METHODS OF EXTRACTION AND
PROCESSING OF AGGREGATES
Process of removing rock, sand, gravel, or other minerals from the ground in order to use them to produce materials for construction or other uses
Quarrying
Moving large amounts of sand, gravel, rock, dirt, and other raw materials to job sites and construction areas.
Hauling
The said materials are Crushed and Ground by the primary
jaw crusher, secondary and tertiary cone crushers.
Allows us to purify and to homogenize the blends in accordance with the requirements set by sieve analysis.
The sand and gravel undergo further complementary
processing such as washing.
Crushing / Screening / Washing
The aggregates are stored in separate areas to avoid mixing
and produce pollution.
Stockpiling
The finished products are delivered where the construction site is located from the aggregate crushing plan
Delivery
CAN WE USE DESERT AND SEA SAND IN CONSTRUCTION?
Desert sand grains are finer and smoother. If their grain size is too small, the slurry slip and the concrete would have poor strength.
Sea sand also tends to be very fine and rounded. Chloride is present which will cause corrosion of steel and iron, so the structure built using this may not be sustainable. Salt in sea
sand tends to absorb moisture from the atmosphere, bringing dampness
Sea and desert sand do not have high compressive strength, high tensile strength etc. So it cannot be used in construction activities.
Uses of Aggregate in Concrete
To provide a rigid structure.
To reduce the shrinkage and cracking
Uses of Aggregate in Roads
Stabilized using cementitious materials
Stabilized with bituminous materials
Uses of Aggregate in Railway Ballast
Stabilized using cementitious materials
Stabilized with bituminous materials
MISCELLANEOUS USES OF AGGREAGATES
Various sizes of stone are used for riprap to protect natural
or man-made earthwork.
Micro-Deval Test
An abrasion loss test carried out on fine or coarse aggregate samples that are
partially submerged in water.
Sulfate Soundness Test
A cyclical test that evaluates aggregates for durability and resistance to
degradation from freeze-thaw cycles.
Durability Index Test
An abrasion loss test that looks specifically at the production of clay-like fines
as an aggregate sample degrades. These fines are known to be detrimental
to asphalt mixtures
Accelerated Polishing Test
Simulates the action of car and truck tires on the coarse aggregates used in
asphalt pavement mixtures.
This abrasion test is a
common test method used to indicate
aggregate toughness and abrasion
characteristics.
Los Angeles (L.A.) Abrasion test
The volume of aggregate may
include solid matter, plus pores in the particles, plus voids
Bulk volume of aggregate
The volume may include solid
matter, plus pores in the particles but not voids
Saturated, surface-dry volume
The volume may include solid matter only, not
pores or voids
Solid volume
The weight may include solid matter, plus enough water to fill the pores, plus free water on the particle surface The weight may include solid matter, plus enough water to fill the pores
Wet weight
The weight may include solid matter, plus enough water to fill the pores
Saturated, surface-dry weight
The weight may include solid matter only
Oven-dry weight
WHAT IS DELETERIOUS MATERIALS?
THEY ARE HARMFUL OR INJURIOUS SUBSTANCES(COATINGS) FOUND IN THE SURFACE OF THE AGGREGATE
IMPACTS OF EACH TYPES ON CONCRETE PROPERTIES AND PERFORMANCE
SALT PARTICLES
ORGANIC IMPURITIES
CLAY LUMPS AND OTHER FRIABLE PARTICLES
LIGNITE AND COAL
ABSORB MOISTURE AND CAUSE EFFLORESENCE
INTERFERE WITH THE PROCESS OF HYDRATION OF CEMENT
WEAKENS BOND STRENGTH BETWEEN AGGREGATE AND CEMENT PASTE
RESULT STRAINING ON CONCRETE; CAUSE POPOUTS; AIR ENTRAPMENT
