Fine Aggregates As per IS specification No. 1542-1960

Learn : Fine Aggregates As per IS specification No. 1542-1960: Sand,Kinds of sand,Pit sand or quarry sand,River sand,Sea sand,Crushed stone,Flyash. Fine Aggregates Particles of fine aggregates pass through 4.75 mm mesh and are entirely retained on 0.15 mm mesh. Most commonly used fine aggregates are sand, crushed stone, ash or cinder and surkhi. Aggregates that do not pass through 4.75 mm mesh are termed as coarse aggregates.             1.  Sand. It consists of small grains of silica and is formed by the disintegration of rocks caused by weather. As per IS specification No. 1542-1960 sand should have the following qualities : (i)        Shall be hard, durable, clean and free from adherent coatings and organic matter and shall not contain appreciable amount of clay. (ii)       Shall not contain harmful impurities such as iron pyrites, alkalies, salts, coal, mica, shale or other materials which will affect hardening…

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Fine and coarse aggregates in construction aggregates

Fine and coarse aggregates,cyclopean aggregates Fine and coarse aggregates,fine aggregate are inert materials mixed with a binding material like cement, lime or mud in the preparation of mortar or concrete. Fine and coarse aggregates shall consist of naturally occurring stones, gravel and sand and shall be hard, strong, dense, durable, clear and free from veins, adherent coating and injurious amounts of disintegrated pieces and deleterious substances. Aggregates shall not contain in excess harmful materials such as pyrites, laminated material, alkali, sea-shells, organic impurities and those which may attack the reinforcement. Aggregates shall not be chemically reactive with alkali of cement. Depending upon the size of their particles the aggregates are classified as fine aggregates, coarse aggregates and cyclopean aggregates. Fine and coarse aggregates make up the bulk of a concrete mixture. Sand, natural gravel, and crushed stone are used mainly for this purpose. Recycled aggregates (from construction, demolition, and excavation waste) are increasingly…

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10 precautions must be taken in storing cement

10 precautions must be taken in storing cement Following 10 precautions must be taken in storing cement : Portland cement is a finely ground material. It, therefore, readily absorbs moisture even from the atmosphere. It is therefore essential to protect it from dampness during storage. Lack of proper care may cause setting of cement or reduction in its strength due to partial setting. (i)        Walls, roof and floor of the building in which cement is to be stored should be completely waterproof. (ii)       In case the cement store is newly constructed then its interior should have been thoroughly dried before cement is stored in it. (iii)     Doors and windows should be properly fitted and should be kept shut. (iv)      Except in case of dry concrete floor the cement bags should be stacked on wooden planks. (v)       The bags should be stacked away from walls. A space of 25 cm all…

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Different kinds of cement as per IS code

Learn : Different kinds of cement as per IS code :Rapid hardening or high early strength,Quick setting,High alumina,portland slag,Low heat,Air entraining Portland etc cement Different kinds of cement as per IS code Following are some of the Different kinds of cement as per IS code manufactured to suit the different requirements. Important Different kinds of cement as per IS code             1.  Rapid hardening or high early strength cement. This cement gains strength faster than the ordinary Portland cement. Its initial and final setting times are the same as those of ordinary cement. It contains more of tri-calcium silicate and is more finely ground. It gives out more heat while setting and is as such unsuitable for mass concreting. It is used for such structures as are to be subjected to loads early e.g. repair of bridges and roads etc. It is more costly than the ordinary cement. It is…

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