Author Archive
Properties of the good building stone
There are Properties of the good building stone The stones must be strong against crushing. The crushing strength should be greater than 100 N\mm2 The stones should have uniform color and decent appearance. Stones should be durable.
Physical properties of cement
The important physical properties of cement are: The color should be grey greenish and of should be uniform. When touched, cement should feel uniform and cool. It should be free from lumps. Cement when thrown into a
Classification of stones
They may be classified in the following four ways. Stones are classified as per the classification if their parent rocks. Geological classification: Igneous rocks, sedimentary rocks, metamorphic rocks. Physical classification: Stratified rocks, unstratified rocks laminated rocks. Chemical
Classification of bricks
Types of bricks Traditional bricks Modular bricks Traditional bricks Traditional bricks are those which have not been standardized in the side. The dimension of traditional bricks varies from place to place. Their length varies from 20 to
Characteristic of good bricks
Bricks should be well – burnt, copper colored. They should be free from crack, fissures, stones etc. Bricks should have perfect edges, required shape and standard size 19 × 9 × 9cm. Bricks should be sufficiently hard
Types of cement
The various types of cement available in the market can be classified as follows: Portland cement Ordinary Portland cement Rapid hardening cement Low heat Portland cement Quick setting cement Sulphate resisting cement Blast furnace slay cement White
What are the uses of cement
Major works of civil engineering in which cement is used are as follows: Cement is a binding material used to bind different type of construction materials together. It is formed from argillaceous, siliceous, calcareous etc. Cement is
Necessity of starter
At starting, heavy current is drawn by the dc motor from the supply as some time is required by the motor to gain speed and hence to built up back emf. If the starter is not present
Characteristics of speed torque
The torque is proportional to armature current, the nature of these characteristics. At no load,Ta is no load speed. As the load is increased, torque also increases. To generate more torque, armature current also increased due to
Different types of motors
Series motor It develops very high starting torque and it has adjustable firing speed. It is suitable for any value of load which needs high starting torque. This motor is widely used in : Electric trains Cranes