Light weight aggregate concrete block

Leca concrete is made by mixing of Leca aggregates, cement and water. Adding sand into the mixture reduces the porous and makes the concrete with a smoother surface. Adding of sand decreases the volume of air in concrete and increases concrete strength.

This kind of block (with addition of sand) is called medium weight concrete block. When fine light weight aggregate is replaced by sand, workability goes high, water-cement Ratio decreases, and the strength of concrete increases.

Using Leca for non-bearing walls will reduce concrete weight and the thermal conductivity. With these particular and above specifications for Leca aggregates, following advantages can be expected from Leca Concrete:

  1. Lower weight
  2. Easy transportation
  3. Reduction of manpower and construction time for its lightness and easy- applying
  4. Easy for plastering on cellular texture and rough surface of the block
  5. Strength against imposed pressures
  6. Durable thermal insulation since the inside porous texture of aggregates and the air existing inside and among the aggregates
  7. Low coefficient of thermal conductivity
  8. Resistance against fire without producing toxic gases in firing
  9. Sound insulation with suitable coefficient of acoustical absorption
  10. Resistance against freezing and thawing cycles
  11. Impermeable against moisture
  12. Resistance against calcareous substances

Table. 1 Leca Aggregate Density

Leca Gradation
( mm )

Mix
( 0 – 25 )

Fine
( 0 – 4 )

Mid
( 4 – 10 )

Density ( kg / m3 )

Max 270

Max 510

Max 320

Table. 2  Leca Light Weight Wall Blocks Specification

Compressive Strenght
(MPa)

Density (kg/m3)

Block Weight (Max. kg)

Dimension
(mm)

Blocks

Nominal Thickness (mm)

2

645

12

Bottom – close

200

2

625

5.7

Bottom – close

2

660

10

400*190*200

Bottom – close

4.5

930

17.3

490*190*200

Solid block

2

750

12

Bottom – close

175

2

670

9.5

Bottom – close

150

2

675

4.7

Bottom – close

2.5

785

9.2

Hollow block

120

 2  750  8.5 200*100*590 Bottom – close

100

2

725

5.8

Bottom – close

4.5

970

4

Bottom – close

4.5

970

8

400*100*200

Solid block

4.5

970

9.5

490*100*200

Solid block

——

1090

1.2

Brick size

4.5

985

6.3

Solid block

80

 

*Test Reference (Aggregate Standard): ASTM C331:2005 Standard Specification for Light Weight Aggregates for Masonry Units.

*Test Reference: ASTM C129:2011,Standard Specification for Nonloadbearing Concrete Masonry Units.