WELCOME

Sant Tukaram Polytechnic,Induri.

Prepared By : ONKAR KADAM (roll no. 307)

Civil Engineering Department

CEMENT

A cement is a binder, a substance used in construction that sets and hardens and can bind other materials together. The most important types of cement are used as a component in the production of mortar in masonry, and of concrete, which is a combination of cement and an aggregate to form a strong building material.

Cements used in construction can be characterized as being either hydraulic or non-hydraulic, depending upon the ability of the cement to set in the presence of water.

CEMENT :-

1. Rapid Hardening Cement2. Quick setting cement3. Low Heat Cement4. Sulphates resisting cement5. Blast Furnace Slag Cement6. High Alumina Cement7. White Cement8. Coloured cement

TYPES OF CEMENT :-

It is always desirable to use the best cement in constructions. Therefore, the properties of a good cement must be investigated. Although desirable cement properties may vary depending on the type of construction, generally a good cement possesses following properties (which depend upon its chemical composition, thoroughness of burning and fineness of grinding).

Provides strength to masonry.Stiffens or hardens early.Possesses good plasticity.An excellent building material.Easily workable.Good moisture-resistant.

PROPERTIES OF CEMENT :

Cement is a very useful binding material in construction. The applications of cement over various fields of construction have made it a very important civil engineering material. Some of the numerous functions of cement are given below.{adselite}

It is used in mortar for plastering, masonry work, pointing, etc.It is used for making joints for drains and pipes.It is used in concrete for laying floors, roofs and constructing

lintels, beams, stairs, pillars etc.It is used in the construction of important engineering structures

such as bridges, culverts, dams, tunnels, light houses etc.It is used in the preparation of foundations, water tight floors,

footpaths etc.It is employed for the construction of wells, water tanks, tennis

courts, lamp posts, telephone cabins, roads etc.

USES OF CEMENT :

There are two methods of manufacturing of cement :

1). Wet process : -

MANUFACTURING OF CEMENT :

2).Dry process :-

The water causes the hardening of concrete through a process called hydration. Hydration is a chemical reaction in which the major compounds in cement form chemical bonds with water molecules and become hydrates or hydration products.

Hydration energy (also hydration enthalpy) is a term for energy released upon attachment of water molecules to ions. It is a special case of dissolution energy, with the solvent being water.

HYDRATION OF CEMENT :

 when water is added to cement it react with the ingredients of the cement chemically & results in the formation of complex chemical compounds terms as BOGUES compounds. which are not for simultaneously.

BOGUE’S COMPOUNDS :

Portland cement gets its strength from chemical reactions between the cement and water. The process is known as hydration. This is a complex process that is best understood by first understanding the chemical composition of cement.

CONSTITUENTS OF CEMENT :

1) . Fineness test :- 100gm cement sample is sieved in 90 microns sieve .Continuously sieve the sample Giving circular and vertical motion for a period of 15 min.• The residue left on the sieve Shall not exceed by the limit given below :- for OPC = 10 gm for rapid hardening cement = 5 gm.

TESTS ON CEMENT :

Standard consistency of a cement paste is defined as that consistency which will permit a vicat plunger having 10 mm dia and 50 mm length to penetrate to a depth of 33-35 mm from top of the mould.

vicat apparatus

2). Standard consistency test :-

Initial setting time is that time period between the time water is added to cement and time at which 1 mm square section needle fails to penetrate the cement paste, placed in the Vicat’s mould 5 mm to 7 mm from the bottom of the mould.

Final setting time is that time period between the time water is added to cement and the time at which 1 mm needle makes an impression on the paste in the mould but 5 mm attachment does not make any impression.

3). Setting time tests :(initial and final)

Soundness means the ability to resist the volume expansion. The hardened cement paste is mixed with boiled water to read the tendency of expanding.

Volume expansion in cement mortar or cement concrete is caused by the presence of unburnt lime (CaO), dead burnt MgO and also CaSO4.

By Le-Chatelier method, we can only find out the existence of unburnt lime (CaO).

The presence of unburnt lime may develop cracks in the cement because of increase in volume.

4 ). Soundness test :

The mortar is placed in moulds. The test specimens are in the form of cubes with side as 70.6 mm or 76 mm. The moulds are of metal and they are constructed in such a way that the specimens can be easily taken out without being damaged. For 70.6 mm and 76 mm cubes, the cement requir

 The moulds are placed in a damp cabin for 24 hours.ed is 185 gm and 235 gm respectively.

The cubes are then tested in compression testing machine at the end of 3 days and 7 days. The testing of cubes is carried out on their three sides without packing. Thus three cubes are tested each time to find out the compressive strength at the end of 3 days and 7 days. The average value is then worked out. During the test, the load is to be applied uniformly at the rate of 350 kg/cm2 or 35 N/mm2.

5). Cube test of cement :

01. Moisture02. Raised floor03. Strictly use no hook04. Keep distance from side wall05. Proper method of stacking06. Store cement bag separately07. Removal of cement08. Store leftover cement carefully09.  Monsoon advisory .

PRECAUTIONS TAKEN WHILE STORING CEMENT : -

THANK YOU