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 main constituents of ordinary portland cement and their respective functions.


The main constituents of OPC and their functions are as under:

1. Lime (CaO) (60% - 70%): This is an important ingredient of cement. Lime in excess makes cement unsound and causes the cement to expand and disintigrate. If there is a deficiency of lime, strength of cement decreases and it causes cement to set quickly.

2. Silica (SiO2): This is also an important ingredient of cement and it imparts strength to cement due to the function of dicalcium and tricalcium silicates. If silica is present in excess quanity, the strength of cement increases but at the same time, its setting time is prolonged.

3. Alumina (Al2O3): This ingredient imparts quick setting property to cement. It acts as a flux and lowers the clinkering temperature. However, high temperature is essential for the formation of a suitable type of cement and hence, alumina should not be present in excess amount as it weakens the cement.

4. Calcium Sulphate (CaSO4): This ingredient is in the form of gypsum and its function is to increase the initial setting time of cement.

5. Iron Oxide (Fe2O3): This ingredient imparts colour, hardness and strength to the cement.

6. Magnesia (MgO): This ingredient, if present in small amount, imparts hardness and colour to cement whereas its high content makes the cement unsound.

7. Sulphur (S): A very small amount of Sulphur is useful in making sound cement. If it is in excess, it causes cement to become unsound.

8. Alkalies: Most of the alkalies present in the raw materials are carried away by the flue gases during heating and cement contains only a amount of alkalies. If they are in excess in cement, they cause a number if troubles such as alkali-aggregate reaction, efflorescense and staining when used in concrete or brick work mortar. Increase in strength beyond age of 28 days is strongly affected by the alkali content. Gain in strength is inversaly proportional.


 

Labels:

Comments

Post a Comment

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

Popular posts from this blog

Fibre Reinforced Concrete

Fibre reinforced concrete is a composite material essentially consisting of conventional concrete or mortar reinforced by random dispersal of short, discontinuous and discrete fine fibres of 25-50mm long and 0.25 to 0.50 mm in diameter, consisting of 4 to 5% weight and of specific geometry. The fibres interlock and entangle around aggregate particles and considerably reduce the normal workability while mix becomes more cohesive and less prone to segregation. The fibres suitable for reinforcing the concrete have been produced froom steel, glass and organic polymers. Naturally occuring asbestos and vegetable fibres, such as jute are also used for reinforcement. Steel, carbon and glass have higher elastic moduli than cement mortar matrix and polypropylene and vegetable fibres are low modulus fibres. High modulus fibres improve both flexural and impact resistance simultaneously whereas low modulus fibre improve impact resistance of concrete but do not contribute much to flexural strength. ...
Post a Comment
Read more

Delegation is neither decentralization nor are their purpose the same.

Delegation is a process, while decentralisation is the end result of delegation and dispersal of authority. Delegation mainly refers to the granting of authority and the creation of responsibility as between the individual and superiors whereas decentralisation is the situation which exists as a result of the systematic delegation of authority throughout the organisation. In delegation, a superior continues to be responsible for the work delegated to his subordinates, while in decentralisation the superior is relieved from his responsibility for the work decentralised and the subordinate become liable for that. Delegation is vital and essential to the management process. Only through delegation, subordinates can be involved in the organisation and the management can get things done. Decentralized is optional, in the sense that it may or may not be practised as a systematic policy.  
Post a Comment
Read more

Funds, Working Capital, Net Working Capital & Income

  Funds are defined as total resources. Industrial enterprises has land, buildings, machinery, tools etc. This type of assets are called fixed capital. An enterprise needs funds to cover its cost of operating. Moreover there is a need of money to carry the enterprise during the time lag between the sale of its products and the payment for them. Funds are needed to cover these costs is commonly called as working capital. Net working capital is simply the difference between current assets and current liabilities. Income from business is found by deducting the outgoings from gross incomings.
Post a Comment
Read more