| S.No. | Field / Checkpoint | Reference | Status |
|---|---|---|---|
| A. SAMPLE | |||
| A1 | Sample no. + truck no. + element being poured Acceptance: Logged | 1 per truck typical | OK NC NA |
| A2 | Time of sampling + concrete temperature Acceptance: Per code | IS 1199 Sec 2 | OK NC NA |
| B. TEST PROCEDURE | |||
| B1 | Slump cone — 300mm height, 200mm bottom dia, 100mm top dia Acceptance: Apparatus checked | IS 1199 Cl. 5 | OK NC NA |
| B2 | Three-layer filling + 25 tamps per layer Acceptance: Per procedure | IS 1199 Cl. 6 | OK NC NA |
| B3 | Cone lifted + slump measured (mm) Acceptance: Read to 5mm | Within 30 sec | OK NC NA |
| C. ACCEPTANCE | |||
| C1 | Slump within mix design target ± 25mm typical Acceptance: Pass / Fail | Per mix design | OK NC NA |
| C2 | Slump out of range → reject load / adjust admixture Acceptance: Action logged | Pour-side decision | OK NC NA |
The slump test is the simplest, fastest, most-performed test on fresh concrete — it measures consistency / workability. Done per IS 1199 Part 2:2018, the test takes 5-10 minutes and provides immediate feedback on whether the concrete is suitable for placement.
Slump value indicates: - Water content + cement-to-water ratio - Workability for the placement task - Mix consistency vs design
For any RCC pour, slump testing is mandatory at delivery + before placement — per IS 456 Cl. 16.2. The Slump Test Log records every test result for every batch / delivery.
Apparatus: Standard slump cone (300 mm height, 200 mm bottom dia, 100 mm top dia), tamping rod (16 mm dia, 600 mm long), flat steel plate.
Procedure: 1. Wet inside of cone + steel plate; place cone on plate, hold firmly down 2. Fill cone in 3 equal layers; each layer tamped 25 times with rod 3. Strike off excess concrete at top with edge of rod 4. Lift cone vertically + smoothly within 5-10 seconds 5. Measure 'slump' = original cone height (300 mm) minus collapsed concrete height 6. Record slump value
Slump classification per IS 1199 Part 2: - 0-25 mm: Very low slump — for very stiff concrete (pavements with vibrating screed) - 25-50 mm: Low slump — mass concrete, foundations, vibrated placement - 50-100 mm: Medium slump — most beam / column / slab pours; standard for RCC - 100-150 mm: High slump — heavily reinforced sections; flowing concrete (with proper admixtures) - 150-220 mm: Very high — self-compacting concrete (SCC) or excessively wet - > 220 mm: 'Collapse slump' — concrete is over-watered or admixture overdose; reject
Typical project specification: 75 ± 25 mm for routine RCC (50-100 mm acceptable range).
1. Slump too high (> spec) — over-watered or admixture overdose; reject the batch. 2. Slump too low (< spec) — under-watered or low workability; risk poor placement. 3. Shear slump — concrete falls sideways instead of slumping uniformly; indicates segregation or wrong gradation. 4. Collapse slump — > 220 mm; concrete totally lacks cohesion; reject. 5. Inconsistent tests — cone not properly cleaned; rod tamping not standardized; results vary. 6. No retest after add-on — water added at site to increase slump; retest needed. 7. No log — slump tested but not recorded; later disputes about whether concrete met spec. 8. Wrong test time — slump measured at batch plant vs site delivery; significant difference due to time-temperature-evaporation. 9. Inadequate sampling frequency — IS 1199 mandates one slump test per batch / delivery / 10 m³; some sites do once a day.
Companion formats: - Daily Concrete Pour Register (FMT-SIT-015) — per-pour log - Curing Register (FMT-SIT-025) — curing duration tracking - Formwork Removal Schedule (FMT-SIT-024) — stripping timeline - Cube test register — strength verification
Codes: - IS 1199 Part 2:2018 — Slump test procedure - IS 456:2000 — RCC code (Clause 16.2 — acceptance of concrete) - IS 10262:2019 — Concrete mix design (workability requirements) - IS 516 Part 1 Sec 1:2021 — Cube compressive strength test