Civil Engineering Today

  Testing Methods For Clay Bricks Before recommending bricks for construction work, their suitability is to be assessed by conducting the following tests:  1. Compressive Strength Test  2. Water Absorption Test  3. Efflorescence Test  4. Dimensional Tolerance Test  5. Hardness Test  6. Soundness Test  7. Structure Test 1. Compressive Strength Test - The crushing strength of a brick is found out by placing it in a compression testing machine. It is pressed till it breaks. As per IS: 1077-1970 the minimum crushing or compressive strength of bricks is 3.50 N/mm2. The bricks with crushing strength of 7 to 14 N/mm² are graded as A. Five bricks are taken at random, and their dimensions are measured accurately to 1 mm. They are immersed in water at 25–29°C for a period of 24 hours. After that they are taken out, and excess moisture is allowed to drain. If the bricks have frogs, they are filled with C.M(cement mortar) 1:3. They are again kept under a jute...

Classification of clay bricks Bricks are broadly classified into two broad categories as follows:  1. Sun-dried bricks and  2. Burnt bricks  1. Sun-dried bricks - Sun-dried bricks also called un-burnt or katcha bricks, and these are dried directly under the sun after the process of moulding. These bricks are of inferior quality and are used for the construction of temporary and cheap structures. Such bricks should not be used in areas exposed to heavy rains. 2. Burnt bricks - Burnt bricks are a type of clay brick that are made by molding, drying, stacking, and then burning to harden. Burnt bricks are more durable than sun-dried bricks.  Burnt bricks are of superior quality, which are generally used for civil engineering constructions.  These are classified into four categories:  1. First-class Bricks 2. Second-class Bricks 3. Third-class Bricks 4. Fourth-class Bricks 1. First-class Bricks - • First-class bricks are table-moulded bricks and ar...

Manufacturing process of bricks In the process of manufacturing bricks, the following four distinct operations are involved: (1) Preparation of clay (2) Moulding (3) Drying (4) Burning.  (1) Preparation of clay -  The clay for bricks is prepared in the following order: (¡) Unsoiling (ii) Digging (iii) Cleaning (iv) Weathering (v) Blending (vi) Tempering. (i) Unsoiling - The top layer of soil, about 200 mm in depth, is taken out and thrown away. The clay in top soil is full of impurities and hence it is to be rejected for the purpose of preparing bricks. (ii) Digging - The clay is then dug out from the ground. It is spread on the levelled ground, just a little deeper than the general level of ground. The height of heaps of clay is about 600 mm to 1200 mm. (iii) Cleaning -  The clay, as obtained in the process of digging, should be cleaned of stones, pebbles, vegetable matter, etc. If these particles are in excess, the clay is to be washed and screened. Such a process natur...

  Bricks   Bricks can be defined as artificial stones which are usually made of clay. These are obtained by moulding clay in rectangular blocks and then by drying and burning these blocks. One of the oldest building material brick continues to be a most popular and leading construction material because of being cheap, durable and easy to handle and work with. Clay bricks are used for building-up exterior and interior walls, partitions, piers , footings  and other load bearing structures. Brick may be made of burnt clay or mixture of sand and lime or of Portland cement concrete. Clay bricks are commonly used since these are economical and easily available. Size of a standard brick (also known as modular brick) should be 190 mm × 90 mm × 90 mm (19 × 9 × 9 cm). When placed in masonry  the 19 × 9 × 9 cm brick with mortar  becomes 20 × 10 × 10 cm. Weight of such a brick is 3.0 kg. An indent called frog, 1–2 cm deep, is provided for 9 cm high bricks. The size of frog ...