RED BRICK CUTTING UNIT

Laterite stones are manual or machine-cut block pieces from the quarries or mines containing lateritic crusts.

Laterite is a soft rock composed of iron & aluminum oxides as the main ingredient. Due to the weathering actions, in hot & wet tropical areas,
Lateritic soil gradually gains strength to become a hard mass.

These hard layers of laterite are cut into blocks of required sizes & transported for the building construction works.

Bricks and tiles may be made from a number of different kinds of materials, but they must usually possess (or be capable of developing) a certain amount of plasticity, so that clay and allied material such as argillaceous shale are, therefore, the most important brick making materials.

Bricks may be classified as being among the most durable of building materials. Indeed, throughout the country, we have many excellent examples of brick work which have survived for hundreds of years. In British, there are some buildings having bricks made by Romans. These buildings are in very good conditions today. It shows that Romans were excellent builders and Engineers. The structures, which can still be seen in many parts of the British Isles, are the live testimonials of Building bricks are broadly classified in two categories

1. Ordinary building bricks &

2. Heavy duty building bricks.

HEAVY DUTY BRICKS

(With Compressive strength over 500 kgf/cm2)

CLASSIFICATION:

The heavy duty bricks shall be classified on the basis of average compressive strength as given below:-

Class Average Compressive Strength
Designation +———————————-+
Not Less Than Less Than
N/mm2 (kgf/cm2) N/mm2 (kgf/cm2)

400 40 (400) 45 (450)

450 45 (450) —

Each class of brick shall be further divided into two Subclasses A and B based on tolerances and shape. The brick of class 400 shall have sub classification 400 A and B and the brick of class 450 shall have sub classification of 450 A and 450 B.

GENERAL QUALITY:

Heavy duty burnt clay bricks shall be manufactured either by pressing or extrusion. They shall be made from processed clay or clays blended in right proportions. The brick shall be burnt to the correct maturing temperature of the clay or clay blend, properly soaked, annealed and cooled under controlled conditions. When broken, the fractured surface of the brick shall show a uniformly dense structure free from large voids, laminations and lime particles. Two bricks when struck together shall emit a clear metallic ring.

The bricks of Subclass A shall have smooth rectangular faces with sharp corners and shall be uniform in colour. The bricks of Subclass B may be permitted to have slightly distorted and rounded edges provided no difficulty shall arise on this account in laying of uniform courses.

DIMENSIONS AND TOLERANCES

Dimensions: The standard size of heavy duty clay building bricks shall be as follows:-

Length Width Height
mm mm mm
190 90 90
190 90 40

The maximum permissible tolerances on the dimensions

Tolerances
Dimensions +————————————-+
Subclass A Subclass B
mm mm mm
190 + 6 + 10
90 + 3 + 5
40 + 1.5 + 2

Bulk Density: The density of bricks shall not be less than 2.5g/cm3.

For obtaining the bulk density, the brick shall be dried in a ventilated oven at a temperature of 105 to 115oC till it attains temperature and its mass shall be obtained. Thereafter, the dimensions of the brick shall be measured accurately and the overall volume computed. The bulk density shall then be calculated as mass per unit volume.

BURNT CLAY BUILDING BRICKS

(With compressive strength less than 400 Kg/cm2)

CLASSIFICATION

The common burnt clay bricks shall be classified on the basis of average compressive strength as given in Table 1.

GENERAL QUALITY

Bricks shall be hand-moulded or machine-moulded and shall be made from suitable soils. They shall be free from cracks and flaws and nodules of free lime.