Skip to main content

The general safety measures taken during civil engineering construction.

The following safety measures are taken during civil engineering construction. (i) Suitable scaffolds should be provided for workmen. (ii) When ladder are used, it should be provided with foot holds and hand holds and inclination of one is to four (1 horizontal : 4 vertical) be provided. (iii) The scaffolding should be properly supported and shall have a guard rail property attached to it. (iv) Every opening in floor of a building should be provided with suitable means to prevent the fall of persons or materials. (v) Fencing and lights shall be provided to protect the public from accident. (vi) The excavated material shall not be placed within 1.5m of the edge of the trench or half the depth whichever is more to avoid collapse of sides due to surcharge. (vii) No undermining or undercutting shall be allowed. (viii) All roads and open areas adjacent to any side where demolition is to be carried out, must be closed or suitably protected. (ix) No electrical cable etc. shall remain electric...
Post a Comment

The process of manufacturing of rolled steel sections.


Following stages are involved in the process of manufacture of rolled steel sections. The purpose of giving mechanical treatment to the steel is to give desired shape to the ingots so as to make steel available in market forms. The mechanical treatment of steel may be hot working or cold working. The hot working is very common. 

Following are the operations involved in the mechanical treatment of steel:

1. Drawing: This operation is carried out to reduce the cross section and to increase the length proportionately. In this operation, the metal is drawn through dyes or specially shaped tools. The drawin is continued till wire of required diameter or cross section is obtained. This process is used to prepare wires and rods.

 2. Forging: This operation is carried out by repeated blows under a power hammer or a press. The metal is heated above the critical temperature range. It is then placed on anvil and subjected to blows of a hammer. This process increases the density and improves grain size of metal. The riveting belongs to forging operations. The process is used for the manufacture of bolts, cramps, etc.

The steel may be either forged free or dye-forged. In the former case, the steel is free to spread in all directions as it is hammered. In the latter case, the steel flows under the blows of hammer to fill inside of a dye and the excess material is forced out through a special groove and then it is cut off. The dye-forged parts have very accurate dimensions.

3. Pressing: This is a slow process and it is carried out in an equipment known as the press. The main advantage of this process in that it does not involve any shock. 

A press consists mainly of a dye and a punch. The dye and punch are suitably shaped to get article of desired shape. The metal is placed on the dye and punch is then lowered under a very heavy pressure.

The metal is thus pressed between dye and punch and article of desired shape is obtained. For preparing articles with wide changes of shape, the pressing is to be carried out in different stages.

This process is useful when a large number of similar engineering articles are to be produced.

Rolling: This operation is carried out in specially prepared rolling mills. The ingots, while still red hot, are passed in succession through different rollers until articles of desired shape are obtained. The various shapes such as angles, channels, flats, joists, rails, etc. are obtained by the process of rolling. It is possible to prepare jointless pipe with the help of this process. The solid rod is bored by rollers in stages until the pipe of required diameter and thickness is obtained.



 

Labels:

Comments

Post a Comment

Kindly let me know, if you want to know anything.

Popular posts from this blog

HOW TO DEVELOP A NEW PRODUCT.

STEPS TO SUCCESSFULLY DEVELOP A NEW PRODUCT: Various phases for successfully developing the product are: 1. PLANNING: It is also known as zero phase since it precedes the project approval and launch of the actual product development process. this phase begins with corporate strategy and includes assessment of technological developments and market objectives. the output of this phase is project mission statement, which specifies the target market for the product, business goals, key assumptions and constraints.  2. CONCEPT DEVELOPMENT: In this phase of concept, the needs of market are identified, alternative product concept are generated and evaluated and a single concept is selected for further development.  3. SYSTEM-LEVEL DESIGN: The system-level design phase includes the definition of the product architecture and the division of the product into sub-systems and components. The final assembly scheme for the production system is usually defined during this phase as well. The ...
3 comments
Read more

Differences between manufacturing and service operations.

Question : What are the important differences between manufacturing and service operations ? (Summer 2005) Manufacturing Operations :  1. Manufacturing involve tangible goods production. 2. Manufacturing involve heavy plant and machinery. 3. Raw materials, work in process and finished goods can be inventoried. 4. Maintenance is often preventive and takes place at production site. 5. Customer is not in the most of the process. Service Operations :  1. Services are usually intangible (ex: buying a ride on a vehicle) 2. Services are often produced and consumed simultaneously. 3. Services have inconsistent product definition. 4. Maintenance is often repair and takes place at customer's site. 
Post a Comment
Read more

Modulus of elasticity & Fatigue Limit

Question 1 (b): Explain what is meant by modulus of elasticity and the fatigue limit.                                                                                        (6 marks) (Summer 2005) Modulus of Elasticity:   Hooke's law states that when a naterial is loaded within elastic limit, the stress is directly proportional to strain. E is the constant of proportionality known as modulus of elasticity and expressed in kN/sqmm (GPa). E for steel is 200 GPa and that for timber is 10 GPa. Fatigue Limit:  When any material is subjected to repeated stresses, it fails at stresses below the yield point stresses. Such type of failure of a material is called fatigue. The stress is plotted against the number of cycles required to produce failure.  A little consi...
Post a Comment
Read more