Points to be Considered for Effective Storage of Cement

The cement should be stored carefully. Otherwise it may absorb moisture from the atmosphere and may become useless for the structural work. Following precautions are to be taken for the storage of cement:

(1) Moisture: 

If moisture is kept away from cement is found that cement will maintain its quality for indefinite period. An absorption of one tola per cent of moisture has no appreciable effect on quality of cement. But if moisture absorption exceeds 5 per cent the cement becomes totally useless. Hence, when cement is to be stored for a long period, it should be stored in airtight containers.

 

(2) Period of storage: 

The loose cement may be stored indefinitely in air tight containers. But it is advisable to avoid storing of cement in jute bags for a period longer than 3 months. If it is unavoidable, the cement should be tested to ascertain its properties.

(3) Piles: 

The cement bags are stacked in piles. It is economical to form a pile of 10 bags of cement. A distance of about 300 mm should be kept between the piles of cement bags and exterior walls of building. The passage of width about 900 mm should be provided between the piles. For long storage, the top and bottom of piles should be covered with tarpaulin or water-proof paper.

(4) Quality of cement: 

The cement which is finely ground is more active and consequently, it absorbs moisture rapidly from the atmosphere. Hence extraordinary precautions should be taken to store finely ground cement.

(5) Removal of cement: 

When cement bags are to be removed from piles of sufficient height, the steps should be formed by taking out two or three bags from front piles. It is also advisable to remove cement in order of its storage period e cement which is stored previously should be taken out first. In other words, the rule of first in, first should be followed.

(6) Storage sheds: 

For storing cement for a sufficiently long period, the storage sheds of special design should be constructed. The walls, roof and floor of such sheds should be of water-proof construction.

Few small windows should be provided and they should be kept tightly shut. The floor should be above ground. If necessary, the drainage should be provided to drain water collected in vicinity of such shed. For determining the size of storage shed, it is found that 20 bags or 10 kN of cement will require about 1 m of space It should be noted that cement, even if stored in the most favourable conditions, loses its activity when stored for a long time. For instance, the storage duration of 3 months and 12 months will cause a reduction in the activity of cement to the extent of about 20% and 40% respectively. Hence it is advisable to reactivate the cement stored for prolonged period. The most effective method of reacting such cement consists in vibro-grinding which ensures greater fineness of cement and makes cement fit for use.