Uploaded by nawirbalo

BLINDING

advertisement
PLAIN CEMENT CONCRETE WORK PROCEDURE
-
Before starting any structural or masonry work directly on the excavated soil, PCC is done to
form leveled surface
Unless specified, a volumetric mix proportion of 1:4:8 or 1:3:6 is normally used for PCC
PCC mixing is generally a manual process
PREPARATION OF PCC
1. Check the center of the excavated pit
2. Check the dimensions and orientation of the excavated pit (length, breadth and depth). Record
the joint measurement.
3. Get the strata checked and approved by the consultant.
4. Clean the pit by removing all loose materials.
5. Water the excavated pit and ram it for better compacted strata.
6. If the surface level of the pit is uneven, do the soling or plum concrete to avoid the excess depth
of the PCC.
7. Prepare the shuttering box of PCC size and place it in position.
8. Get the required material stocked a day in advance.
9. Get the cement checked and keep it ready by cleaning, washed, lubricating, etc.
WORK PROCEDURE FOR PCC IN FOUNDATION
1. After completing the preparation, PCC should be done. It includes batching, mixing, placing and
compacting. The procedure to be adopted is as follow.
2. Prepare the volumetric depos of sand and metal on the mixing tray, by taking the specified
proportionate quantities. It is advisable to dump depos required for half a bag for better and
uniform mixing.
3. Mix half bag, at a time, with proportionate depo of the aggregate.
4. Mix the dry depo thoroughly using spade. Confirm that the cement, sand and metal are
uniformly mixed.
5. Pour the required quantity of water in the above mixture, to maintain the water-cement ration
and to get workable concrete.
6. Pour the concrete in place.
7. Spread and level the concrete.
8. If the depth of the pit is more, one labour should receive the concrete in the pit and pour the
concrete in position to avoid segregation.
9. The concrete can be compacted depending upon the depth of the PCC
10. The sides of the shuttering should be tamped and finished with thapi to get a smooth and
uniform finish after deshuttering
11. The top surface should be level and finished by randha or tipani to get a uniform finish.
CURING OF PCC
1. Curing of PCC may be done either by pouring water with bucket or with a curing pipe.
2. The centers of the respective columns are marked on the PCC either by nailing or by using a
cement mortar.
DO’S AND DON’T OF PCC WORKS
DO’S
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Check and get the strata approved by the structural consultant before PCC
PCC shuttering should be of the exact size and thickness
Dry depo should be uniformly mixed before adding water to it.
Water should be mixed with a bucket, in a measured quantity as per W/C ratio.
Use the chute or additional labour to pour the concrete where the depth is more.
Remove any loose material from the sides of the pit, so that no soil or other material will
collapse in the pit during concreting.
If the water table is high, de-watering should be carried out simultaneously during concreting.
Compact and level the concrete properly.
Maintain the level of PCC
Mark the center of the column, the next day.
DON’T’S
1.
2.
3.
4.
5.
6.
Do not mix the depo on bare hand.
Do not mix the water in depo by mean of a pipe.
Do not allow the PCC without formwork
Do not pour concrete without leveling and compacting.
Do not pour the concrete in the pit from a height of more than 1.5m.
Do not allow extra cement mortar on top of PCC for smooth finishing.
Download