TYPES OF CONCRETE BLOCK, THEIR ADVANTGES AND COMPOSITION

                                                                 Concrete Blocks

 Followings are the types of blocks:

• Solid Concrete blocks
• Hollow concrete blocks

Solid Concrete Blocks

  It is is used for internal load-bearing walls and beam and block floor systems. A solid block is used in the form of a cavity or solid walls construction.

Hollow concrete blocks

 Hollow concrete blocks are one of the useful construction material, these are lightweight blocks and used for load-bearing on non-load bearing walls. In general practice, hollow concrete blocks are 30 cm X 20 cm X 15 cm ( 12inch x 8inch x 6 inch )  in size. In general practice, for hollow concrete blocks, the face thickness must be at least 5 cm (2”)  and the net area must be 55 to 66% of the gross area. And the mortar used has a cement aggregate mix in 1:6 proportion. the blocks used for structural purposes should be at least 3 N/mm2( 450 lb /in2)

Types of Hollow Concrete blocks

•  Stretcher (3core)
•  Double corner
• Low web bold beam block 
• Channel bond beam or lintel block 
• Control joint
• Concrete End block
•  Corner block

(i) Concrete stretcher (3 core):

The shapes of this block is shown in fig below

Hollow concrete blocks 3 Core type

It is most common for reinforced concrete structures.

(ii) Concrete Double corner:

Concrete Double Corner is typically used for reinforced construction, the last course with a vertical steel bar and grout creates internal reinforced concrete columns. 

                                                               Hollow concrete blocks Concrete Double Corner

(iii) Low web bold beam block:

It provides space for horizontal reinforcing bar and grout. It is used to tie the wall together at critical points of creating a bond beam.

                                                             Hollow concrete blocks Low Web Bold Beam Block

(iv) channel bond beam or lintel block:

It provides space for a horizontal reinforcing bar. It used to create lintels over openings.

(v) control joint:

It is used for making the expansion of vertical share type control joints in construction. A sealant is used between interlocking units.

                                                          Control Joint Concrete Block

(vi) End block:

It is used where the end of the unit will be exposed.

  End Concrete Block

(vii) corner block:

The corner block is a half-block used at corners and ends of walls to create a running bond pattern.

  Corner Concrete Block

Advantages of using hollow concrete blocks:

Following are the main advantages of hollow concrete blocks:

•  There is no need for dressing,  due to this construction works is done fastly.
• Concrete blocks easy to handle because of lightweight.
• There are great savings in materials.
• Due to the large size, the number of joints in masonry is less saving mortar.
• In the concrete block, there is hollow space inside so the result has better insulating properties against sound, heat, and dampness.
• A concrete block masonry wall is economical because the meter cube cost of stone machinery was is about 15 to 20 percent Les expensive than a bat of brick masonry walls.
• The maintenance cost of hollow concrete blocks is lesser because it has no efflorescence effect.
• It is eco friendly because, in hollow blocks, constituents can be substituted by waste products like fly ash.
• Concrete blocks work no need any plasterwork because it can easily balance the change in environment or atmospheric conditions.

Composition of concrete blocks

High-density concrete blocks are manufactures and cast by mixing Portland cement, aggregate, sand, and fine gravel. Lightweight concrete blocks are cast by home recycle materials, post-consumer glass, slag cement, or recycled aggregate and industrial wastages such as fly ash or bottom ash.