Concrete Flashcards
3 Structural Concrete
Plain concrete, Reinforced Concrete and Pre-stressed Concrete
Concrete without steel bars
Plain Concrete
Plain concrete is used in
- slabs-on-grade
- pavement
- basement walls
- small foundations
- Curb and gutter
Concrete with steel bars
Reinforced concrete
Properly placed reinforcement in concrete improves its
Compressive Strength and
Tensile Strength
CONCRETE INGREDIENTS:
1.Water
2. Cement
3. Aggregates (Sand & Gravel)
4. Additives (Optional)
These materials are mix in a measured amount to make a workable concrete, that
is easy to:
a. Transport
b. Place
c. Compact
d. Finish
binds aggregates such as sand and gravel or crushed
stone, which turn into a rock like mass especially if properly constructed.
Cement-water mixture
is the chemical reaction when cement and water are mix
together.
Hydration
Portland cement is usually made of materials:
- Limestone or marl
- Shale or clay
CLASSIFICATION OF CEMENT
- Hydraulic Cement
- Non-Hydraulic Cement
are those which harden by hydration in the presence of
water.
Hydraulic Cement
will harden with the help of carbon dioxide (CO2
) from
the air.
Non-hydraulic Cement
TYPES OF CEMENT
Type I - Ordinary Portland Cement
Type II - Modified Portland Cement
Type III - High-Early-Strength Portland Cement
Type IV - Blast Furnace
Type V - Portland Pozzolan Cement
Type VI - High Alumina Cement
Type VII - Quick Setting Cement
Type VIII - Sulphate Resisting Cement
Type IX - White Cement
Type X - Colored Cement
Type XI - Air Entraining Cement
Type XII - Expansive Cement
Type XIII - Hydrophobic Cement
Type I - Ordinary Portland Cement is used for:
- Highways
- pavements
- sidewalks
- buildings,
- bridges
- masonry units
- soil-cement mixtures
Type II -Modified Portland Cement is used for:
- Large piers
- heavy abutments,
- heavy retaining walls,
- when the concrete is placed in warm weather
- drainage structure
Type III - High-Early-Strength Portland Cement is used for:
- when superior strength is required in a short time
- In cold-weather construction
- when forms are to be removed immediately
Type IV - Blast Furnace Cement
is used for structures designed to resist chemical attack
Type V - Portland Pozzolan Cement
is a low hardening characteristics concrete cement
Type VI - High Alumina Cement is used for:
is used for high temperature, frost and acidic action
Type VII - Quick Setting Cement
is used for underwater construction, rainy and cold weather conditions, and also in higher temperature where water evaporates easily
Type VIII - Sulphate Resisting Cement is used for
construction in contact with soil or groundwater
Type IX - White Cement is used for
for decorative work
Type X - Colored Cement is used for
use for different decorative work
Type XI - Air Entraining Cement is used for
where temperature is very low
Type XII - Expansive Cement is used for
construction of the pre-stress concrete component
Type XIII - Hydrophobic Cement is used for
construction of water structures such as dams, spillways, or other submerged structures
portland cement is a ________ that must be protected from dump air or moisture
moisture-sentive material
most types of portland cement are ship in bulk by
rail, truck, or barge
Followings are the different situations against which precautions are to be taken
- moisture content at place of storage
- duration of cement storage
- place of cement storage
- arrangement of cement bags
- withdrawal of cement bags
improves finest quality of long periods stored cement and make it fit for the constructional purpose
Vibro-grinding
a wooden platform of height is required to avoid direct contact between floor and cement bags
150 to 200mm
the cement stack should not touch the walls of the shed and it should be considerably ___ away from the external walls
300mm
Aggregates properties:
- Strong
- Durable
- Chemically inert
- Occupy 60% to 70% of the concrete mix in volume
Sources of Aggregates
Natural Aggregate
Crushed Aggregate
Classification Of Aggregates
Coarse Aggregates
Fine Aggregates
Kinds of Additive
- Airi-entraining agents
- Retarders
- Accelerator
- Plasticizers and Super lasticizers
- Pigments
- Fly Ash
- Ground granulated blast-furnace slag
- Silica Fume