1. Marking for excavation
2. Excavation up to 5'x5'x5' or as mentioned by St. engg
3. PCC 1:4:6 (40mm) up to 3" to 4" and curing
4. Marking inside the excavation area/pit for ensuring steel work placed are aligned - I dont recall the exact technical term for this
5. steel work - Making and placing of Steel mat, pedestal and column
6. placing centering plates around the steel work to hold the concrete mix
7. pouring concrete mix of M:20 ratio at a height as specified, usually 15" to 21". Using vibrator to ensure concrete is uniformally set. Curing for 4 to 5 days
8. pedestel/column job will be next
From my recent expericence things to keep in mind,
1. Excavated soil should be put as far away as possible from the pit or else it keeps pouring back. Soil when mixed with cement will reduce cement strength - This was a problem at my site as, soil would keep falling back
2. Contractor should get or make a temprory ladder for 2 reasons,
a) owner/engg can climb down the pit and inspect work
b) it helps reduces soil pouring back to the pit each time worker goes inside or outside
No contractor does this as they can get away cheating by placing less thinkness of cement.
3. Ensure PCC thinkness is per specification given to you - For me the sump flooring per plan it should have been 6" PCC, but they placed only 4", However i was able to hold contractor responsible for the same
4. When doing centering work (placing steel board to hold the concrete on all 4 sides of the footing/steel mat), ensure there is gap of 2" b/w steel and board on all 4 side and also 2" gap b/w steel and the PCC flooring. This will ensure concrete will cover steel from all side. This job should be done before next step. So demand that your contractor does the centering job on saturday and concrete pouring on sunday. make this a condition. - For me 4 and 5 where done on the same day and I was running b/w two place and keeping tight control of both work to ensure quality. very difficult
5. Concrete mix (for sqft contractor and item rate contract) - All contractor and gangmen have understanding, they dont even need to speak to each other to plan out
hence ensure you have one person either friend or relative at the mixer and ratio is per specification and another person or yourself at the pit location where they are pouring concrete. To ensure quality of concrete mix
a) Based on the specification your engg has given you can calculate the amount of cement bags required and then actual quantity used . What i mean here is, calculate the total cft of concrete required from 1) WxLxB of concrete required in each pit 2) no. of pits, 3) sump area if any 4) concrete mix ratio.
b) if you see all the gangmen are very busy putting sand, cement and jelly continously into the mixer, you are being dumped. Just check this, when they follow the speification of mix, there will be wait time for both sand and jelly workers and only cement worker will be busy.
6.while pouring concrete due to it's mass and since laborer pour only from one side of the pit, steel mat can get displaced and you will end up with misalinged column. hence in #5 I mentioned you need one person at the pouring location. This happened to one of the column but contractor didnt do anything till i noticed it but by then concrete job was done (I was runnning b/w mixer and pit), when i mentioned they adjusted it by putting a pole and pulling it back.
Need to discuss with engg to see what are the outcome of this action. If anyone here on this forum with exp/knowledge on this please help.
7. While pouring concrete one of the rings on the pedestel opened up, it can be placed back while doing pedestel concrete. However my uncle who has exp. in this field and he is from Delhi, mentioned that in Delhi, they weld steel instead of using binding wire as here in Bangalore. Please find out how much feasible this would be as welding will be better option. Also they paint antirusting paint on all steel work before placing it in Delhi. As mostly we use borwell water for construction work, this also is a good thing to check cost benefit. The binding wires are low grade and they start rusting within 1 day
8. gunngy bag should be placed and curing should start from next day of pouring concrete
Heart ache to see after paying them agreed money (which is also market standard), contractor's cheat at all possible places or do substandard work.