Concrete blocks Manufacturing of concrete blocks Types of concrete blocks Advantages and disadvantages Uses of concrete blocks

1. BLOCKS
CONCRETE BLOCKS.

2. CONTENTS:
• Introduction
• Manufacturing
• Types
• Advantages
• Disadvantages
• Uses

3. INTRODUCTION
• It is a standard size rectangular block used in building construction.
• Also known as “Concrete masonry unit (CMU)”.
• Concrete blocks are precast.
• Mostly concrete blocks have one or more cavities and their sides may be smooth
or contain a design.
• Concrete blocks are held together with fresh concrete mortar.

4. MANUFACTURING OF CONCRETE BLOCKS
• Concrete blocks are manufactured in fully automatic plants which produces
concrete blocks of superior quality and high strength
• Production of concrete blocks in such plants is expensive.
• Manually operated machines are also available which can be installed at project
site itself.
• Manually operated machines reduces the transportation cost of concrete blocks.
• It is manufactured in 4 steps:

5. 1.SELECTION AND PROPORTION OF INGREDIENTS
• Concrete blocks are made up of aggregates (fine and coarse), cement and water.
• Ingredients are selected according to the desired strength.
• Strength, texture and economy of concrete blocks depends upon the careful grading of
aggregates.
• Crushed stones, gravel, volcanic cinders and furnace clinker etc. are used as aggregates.
• Aggregates are selected by considering the weight, texture or composition of unit designed.
• Cement used is ordinary Portland cement.
• Water required is normal potable water

6. 2.MIXING OF INGREDIENTS
• Blending of aggregates, cement and water should be done
very carefully.
• It is better to mix the ingredients in a mechanical mixer.
• Extreme care should be taken for hand mixing (Dry mixing).

7. 3.MOLDING
• The concrete mix is fed into the mold box up to top level.
• It is ensured that the box is filled up to top level.
• Vibration of concrete is done till it has uniformly settled in the mold box,
• Excess concrete mixture is removed from the face of mold and levelled by using
plywood.
• Concrete mixture used for blocks contain higher %age of sand and lower %age of
gravel and water than the concrete mixtures used for general construction
purposes.This produces a very dry, stiff mixture that holds its shape when it is
removed from the block mold.

8. 4.CURING
• The block is watered after about one day of casting.
• Curing is continued for minimum 7 days and maximum 28 days.
• Longer the curing period, better will be the block.

9. TYPES OF CONCRETE BLOCKS
• Classified into 2 types:
• 1. Solid Concrete Blocks:
-Heavy in weight.
-Manufactured from dense aggregate.
-Very strong and makes the structure very stable.
-Preferable to be used in load bearing walls.
-Available in large sizes than bricks, hence less time is required for construction.

10. 2. Hollow Concrete Blocks:
-Contain voids greater than 25% of total area.
-Solid area should be more than 50%.
-Manufactured from lightweight aggerate.
-Light weight blocks and are easy to install.
TYPES OF CONCRETE BLOCKS

11. TYPES OF HOLLOW CONCRETE BLOCKS
• Stretcher block
• Corner block
• Pillar block
• Jamb block
• Partition block
• Lintel block
• Frogged brick block
• Bull nose block

12. • Stretcher Block: • Corner block:

13. • Pillar Block: • Jamb Block:

14. • Partition Block: • Lintel Block:

15. • Frogged Brick Block: • Bull Nose Block:

16. ADVANTAGES
• Its width is less than bricks due to which carpet area increases.
• Better thermal insulation, fire resistance and sound absorption.
• Saves precious agricultural lands which are used for manufacturing bricks.
• Construction of blocks is easier, faster and is stronger than brick.
• Perfect shape makes the masonry work very simpler.
• No real need for plastering.
• Environment friendly.

17. DISADVANTAGES
• Wider and larger cracks.
• Shrinkage due to movement of moisture.
• Expensive.
• Plumbing issues.

18. USES
• Retaining walls, to keep soil and water away from certain areas.
• Security Barriers.
• Buildings and houses.

19. THANKYOU