| S.No. | Checkpoint | IS Requirement | Status |
|---|---|---|---|
| A. INITIAL SET & FINISHING | |||
| A1 | Surface finishing completed before initial set — smoothing, leveling done Acceptance: Surface leveled and screeded at design level ±10mm, no trowel marks or tool indentations present, finished smooth without over-working (which causes dusting), completed within 4–6 hrs of placement | Cl. 13.5 — Surface finishing shall be completed before initial set (typically 4–6 hrs for OPC) | |
| A2 | No disturbance to concrete after finishing — no foot traffic, no vibration Acceptance: Area cordoned off or marked with 'No Entry' signs after finishing, no formwork removal tools dropped/left on surface, no vehicle traffic, no vibration or impact for ≥24 hrs | Cl. 13.5 — Concrete shall not be disturbed until initial set achieved | |
| A3 | Bleed water managed — removed from surface if excessive (>3mm pool depth) Acceptance: Remove standing bleed water using squeegee or absorbent material (hessian), do not allow water to sit on surface >2 hrs, if bleeding continues (W/C ratio issue) document and raise NCR; drain installed if element is horizontal | Cl. 13.5 — Bleed water at surface must be managed to prevent scaling and weak surface | |
| A4 | Surface level verified at 4 corners and mid-point — recorded against design elevation Acceptance: Surface level ±10mm of design elevation (measured with level or laser), levels recorded on site log, any deviations documented and escalated if >10mm; correction approach documented | Cl. 13.5 — Concrete surface shall be at design elevation | |
| B. CURING COMMENCEMENT (Cl. 13.5, 14) | |||
| B1 | Curing started within 24 hours — method decided (wet, compound, ponding) Acceptance: Curing initiated by hour 24 post-placement; method chosen (wet hessian for slabs, curing compound for walls/columns, or ponding for tanks); method consistent with design and climate | Cl. 13.5 — Curing shall commence within 24 hrs of placing concrete | |
| B2 | Curing method selected — wet hessian, curing compound, or continuous water spray Acceptance: Wet hessian: wetted twice daily (morning & evening), hessian not allowed to dry out; curing compound: applied within 24 hrs at rate 0.3–0.4 L/m², not reapplied if compound fails; continuous water: 24/7 moisture via sprinklers or drip lines | Cl. 14.1 — Method must keep concrete continuously moist | |
| B3 | Water supply arranged for curing — quantity and access to source confirmed Acceptance: Water supply line to site confirmed, tanker capacity adequate for daily use (rule of thumb: 0.5–1 L/m² per day), water quality acceptable (not stagnant/polluted), spraying system tested | Cl. 14.1 — Continuous water supply required for minimum 7–14 days | |
| B4 | Curing material cost-optimized or performance method selected per project budget Acceptance: For structural RCC: wet hessian preferred (cost-effective, proven), for large areas: curing compound option (reduces water usage), for critical elements: continuous water spray (best performance) | Curing method choice depends on cost and performance targets | |
| C. CURING DURATION (Cl. 13.5, 14.2) | |||
| C1 | OPC concrete — minimum 7 days curing confirmed Acceptance: Curing period: 7 days minimum for OPC at normal temperature (15–25°C); documented on site log with start date, curing method, end date; if temperature drops below 5°C, extend duration by 3–5 days | Cl. 13.5.1 — OPC concrete cured minimum 7 days under wet conditions | |
| C2 | PPC/PSC concrete — minimum 10 days curing confirmed Acceptance: PPC/PSC: minimum 10 days wet curing (longer hydration time needed for pozzolanic reaction), documented with proof of cement type from MTC, end date clearly marked on site log | Cl. 13.5.1 — PPC (Pozzolana Portland Cement) requires longer curing | |
| C3 | High-performance concrete (strength >M40) — minimum 14 days curing Acceptance: For M40, M45, M50 grades: minimum 14 days continuous wet curing to achieve target strength; extension required if ambient temp <10°C; documented in element QC log | Cl. 13.5.1, 14.2 — High-strength concretes need extended curing for development | |
| C4 | Water-retaining structures (tanks, reservoirs) — minimum 14 days Acceptance: Tank walls, foundations: 14 days minimum wet curing, continuous moisture maintained; test for water tightness after curing period (hydrostatic test or air pressure test) | Cl. 14.2 — Structures holding water need strong, dense concrete | |
| C5 | Temperature correction — curing duration extended if average temp <10°C Acceptance: If daily avg temp <10°C: extend curing by 3–5 days (document daily temperatures), cold weather concreting (IS 7861 Part 2) measures applied; no reduction below minimum 7 days | Low temperature slows hydration; curing extended accordingly | |