PRECAUTIONS WHILE PURCHASING CEMENT
Cement is the most important raw material used in a building. You should ensure the quality of ‘Cement’ using the following guidelines.
1. The cement should be factory manufactured instead of plant manufactured.
2. The cement should be packed in the bags of synthetic jute or polypropylene bags.
3. The cement bags should not be hand stitched.
4. The cement bag should bear manufacturer's name or his trade mark on it if any.
5. The cement bag should bear the grade and type of cement.
6. The cement bag consignment must have identification mark on package.
7. The cement bag should indicate the date of manufacturing.
8. One cement bag should have 50 Kg. weight.
9. The cement bags should not be older than six weeks from the date of manufacturing.
10. Do not purchase cement bags which are partially set due to moisture. Do not purchase if there are small lumps in the bags.
11. Do not purchase cement bags which are pressed or have lumps due to high pressure of stack having more than 10 to 12 bags.
12. Do not take cement bags which are torn by side and stitched in later.
PRECAUTIONS WHILE TRANSPORTING THE CEMENT BAGS
1. Care should be taken to carry the bags in a clean vehicle which is not dustier or on earth etc. It will reduce the strength of the cement.
2. During monsoon season the cement should be carried under covered Polythene or ‘Tarpaulin’.
3. Care should be taken that the labor should not tear the bags while loading and unloading the cement bags.
WHILE STACKING CEMENT AT SITEStore cement in a moist proof storage area other wise quality of cement will be affected.
1. Cement should be stacked in a shed/fumes which is dry, leak proof and moisture proof.
2. Cement should be placed on dry brick floors, on wooden crates or on the planks.
3. In any case the cement bags should not be stored on the earth.
4. The stack should not be higher than 10 bags to avoid lumps under pressure.
5. The cement bags should not be stacked with outer wall.
6. Cement from different manufacturers should be stacked separately.
7. The cement should be used on first come first used basis.
8. During monsoon season cement bags should be covered with polythene.
9. The cement bags should be kept close together to reduce air circulation.
CAUTION:
1. When construction work is given to a contractor, make sure he takes proper care of the cement. A lot of time contractors do not care for proper storage of the cement at site as it costs them labor time (money). This results in reduction of strength of cement as the table below shows.
2. In some cases it has been seen that after laying the RCC slab on some part of the building, the contractor dismantles his temporary store at the site and places cement on ground floor of the building which is under construction. This is not good as the cement bags may draw moisture from the floor and walls as the new building is wet due to construction work in progress, which results in reduction of strength in cement.
REDUCTION IN CEMENT STRENGTH DUE TO STORAGE
| S. No |
Storage Period |
Reduction in Strength |
| 1 |
Fresh cement |
Nil |
| 2 |
Three months old |
20% |
| 3 |
Six months old |
30% |
| 4 |
12 Months old |
40% |
| 5 |
24 Months old |
50% |
1. Due to absorption of moisture by cement during storage, cement retards in hardening and reduces the strength.
2. It is okay for cement to absorb up to 1.2% moisture as this level of moisture is acceptable but if absorption exceeds 5%, cement, the cement is destroyed for all practical purposes.
3. Different types of cements should not be mixed while using them for constructional purposes.
PRECAUTIONS WHILE PURCHASING BRICKS
Before you go to buy ‘Bricks’, keep in mind the points given below.
1. Bricks should be purchased from the kilns which are not situated on salty earth and water-logged area.
2. Some kilns owners prepare bricks under size and sell them at cheap rates but these bricks will be consumed more in numbers because the bricks are under sized. So the size of the bricks should be checked i.e. 9” X4-3/8” X 2-11/16”.
3. Bricks under size create problems of joints during construction of masonry.
4. Bricks should be first class having uniform color i.e. Cherry red free from cracks and bricks should have ringing sound when these are struck against each other.
5. Bricks should not show appreciable sign of efflorescence (Whiteness).
6. Sample of bricks should be kept at site if the rate and quality suit to your requirements. While accepting delivery make sure whether the delivered material matches the sample agreed upon.
PRECAUTIONS WHILE TAKING SUPPLY OF THE BRICKS AT SITE
Be careful while taking the supply of ‘Bricks’
1. Generally it is seen, if the payment is given in advance, there is a chance for the kiln owners to supply mixed or sub standard bricks.
2. The supply should be taken during the day in the presence of you or person deputed for this job.
3. Some suppliers use the following practices during the supply of bricks. Make sure you keep an eye on these.
- Sub standard bricks which are not seen at the time of counting are put in the middle of stack while stacking the bricks at site.
- In some cases while stacking the bricks they put some bricks bats or broken bricks in stacks.
- In some cases while stacking the bricks, labor leaves the gaps in middle in one or two layers at ground and this will affect the quantity of bricks during counting.
- While taking supply of the bricks give the receipt of quantity after counting the bricks every time.
- If the supply is not made in your presence, give the receipt of bricks after counting and checking the quality of the bricks properly.
- While making payments to the supplier, the quantity should be checked from the receipt given by you and take the receipts back after making the payments. Also take proper receipt of the payments to avoid any dispute in later.