RCC methodology ppt

1. RCC FOUNDATION
METHODOLOGY FOR CONSTRUCTION OF R.C.C FOUNDATION

2. SURVEY & SETTING OUT
• Survey department will establish baselines and benchmarks from which co-
ordinates and elevations will be taken to set out the foundation works.

3. CHECKLIST AS PER QAP

4. EXCAVATION
• Excavation will be executed in open cut to the size, slope and
elevation as per drawing.
• Excavation will be carried out with excavator and soil loaded into
dumper and transported to stockpile area.
• The final bottom level of foundation will be checked by survey
team and surface will be trimmed as per the size and shape.

5. PCC
• Bottom of the excavation should be dry and tamped in uniform level before
placing lean concrete blinding layer.
• After inspection of the prepared foundation level, blinding concrete will be laid.

6. PLACING OF REINFORCEMENT
• Reinforcement shall be bent and fixed in position shown in the
drawings.
• Cover block shall be provided and required support for reinforcement
will be ensured.
• Spacing, Lab length and cover to the reinforcement shall be as per
drawing.
• The cover shall in no case be reduced by more than one third of the
specified cover or 5 mm, whichever is less.
• Any embedded items, fixtures etc., to be fixed as per drawing with
proper support to avoid dislocation during concrete pouring.
• Reinforcement shall be properly stored in firm, levelled ground at-least
above 150mm from ground to avoid contact with water, oil, grease,
slush/ mud which will reduce the bonding with concrete.

7. CHECKILIST AS PER QAP

8. FORM WORK
• The formwork shall be designed and constructed to the shapes, lines and dimensions
shown on the drawings. All forms shall be sufficiently watertight to prevent leakage
of mortar.
• Formwork shall be aligned vertically and horizontally with line and level as per
drawing.
• Rigid support to be ensured to withstand load during pouring of concrete.
• Formwork interior surface shall be properly lubricated by oil for ease for removal and
good surface finish.
• Damaged formwork shall not be used for shuttering works.
• Proper working platform to be provided for safe moving of manpower for
consolidation of concrete.
• Formwork shall be removed in such a manner as would not cause any shock or
vibration that would damage the concrete.

9. CHECKLIST AS PER QAP

10. FORMWORK REMOVAL DURATION

11. PLACING OF CONCRETE
• Before placing the concrete in trenches or on sub-grade or sub base, the sub-grade/ sub
base shall be cleaned of all injurious or foreign matter, watered and well consolidated, if
necessary.
• The concrete shall be deposited as nearly as possible in its final position to avoid re-
handling.
• The concrete shall be placed and compacted before setting commences and should not be
subsequently disturbed.
• Methods of placing should be such as to prevent segregation.
• Care shall be taken to avoid displacement of reinforcement or movement of formwork
during placing.
• Concrete shall not be allowed to free fall of height more than 1.5m to prevent segregation.

12. CONSOLIDATION OF CONCRETE
• Concrete shall be placed in a layers and each layer shall be thoroughly compacted and
fully worked around the reinforcement, around embedded fixtures and into the corners
of the formwork.
• The concrete shall be consolidated by means of internal vibrators vertically into it.
• Vibrator shall not be moved laterally to spread the concrete. Shovel/ spade shall be
used to move the concrete from one place to other.
•

13. FINISHING METHODS
• Screeding
• Floating

14. CHECKLIST AS PER QAP

15. POST CONCRETE FINISH
• Immediately after stripping the formwork, all concrete shall be carefully inspected
for any defective work and defects either removed or made good before the
concrete has thoroughly hardened.

16. CHECKLIST AS PER QAP

17. CURING OF CONCRETE
• Exposed surfaces of concrete shall be kept continuously in a damp or wet condition by covering
with layer of sacking, canvas, Hessian or similar materials or a layer of sand or by ponding for at
least seven days from the date of placing of concrete.
• Approved curing compounds may be used in lieu of moist curing.
• Such compounds shall be applied to all exposed surfaces of the concrete as soon as
possible after the concrete has set.

18. CHECKLIST AS PER QAP

19. BACKFILLING
• Backfilling will be carried out upto top of the
foundation level in loose layers not more than
250mm in thickness.
• Suitable vibrator/ rollers will be used to achieve
the 90-95% compaction as per MDD of the soil
used in each layer.
• Density test will be carried out for each layer to
confirm the compaction requirement.