| S.No. | Checkpoint | IS Requirement | Status |
|---|---|---|---|
| A. SAMPLE DETAILS | |||
| A1 | Date of Casting Acceptance: Valid date, format DD/MM/YYYY HH:MM | Record exact date and time of casting | OK NC NA HOLD |
| A2 | Pour Location / Element Acceptance: Clear identification of structural element (column, beam, slab, etc) | Identify exact location and element being concreted | OK NC NA HOLD |
| A3 | Mix Design Number & Grade Acceptance: Grade designation (M25/M30/M35/M40/etc), valid mix design reference | Link sample to approved mix design and target grade | OK NC NA HOLD |
| A4 | Water-Cement Ratio Acceptance: Within approved mix design ±0.02 | Record actual W/C ratio of sample | OK NC NA HOLD |
| A5 | Slump at Time of Sampling Acceptance: Within target slump ±25 mm | Measure slump before cube casting | OK NC NA HOLD |
| A6 | Ambient Temperature Acceptance: 10°C to 35°C (above/below requires special measures) | Record ambient temperature during casting | OK NC NA HOLD |
| A7 | Concrete Temperature at Sampling Acceptance: 12°C to 32°C, typically 27±3°C | Record fresh concrete temperature | OK NC NA HOLD |
| B. CUBE IDENTIFICATION TABLE | |||
| B1 | Cube ID / Label Acceptance: Format: PRJID-ELEMID-POUR-CUBENUM (e.g., PRJ001-COL01-P001-C1) | Unique identification for each cube specimen | OK NC NA HOLD |
| B2 | Mould Number Acceptance: Valid mould reference, mould calibration within 12 months | Record steel mould identification | OK NC NA HOLD |
| B3 | Date Cast Acceptance: DD/MM/YYYY format | Date cube was filled with concrete | OK NC NA HOLD |
| B4 | Date Tested Acceptance: At 7 or 28 days (±8 hours), or as specified | Date cube was tested for compression | OK NC NA HOLD |
| B5 | Age at Test (days) Acceptance: 7±0.33 days or 28±2 days (typical) | Calculate actual age from cast to test date | OK NC NA HOLD |
| B6 | Cube Dimensions (mm) - Length Acceptance: 150±2 mm (standard 150 mm cube) | Measure length of cube specimen | OK NC NA HOLD |
| B7 | Cube Dimensions (mm) - Width Acceptance: 150±2 mm | Measure width of cube specimen | OK NC NA HOLD |
| B8 | Cube Dimensions (mm) - Height Acceptance: 150±2 mm | Measure height of cube specimen | OK NC NA HOLD |
| B9 | Mass of Cube (kg) Acceptance: 8.0 to 8.5 kg typical (density check) | Weigh cured cube before testing | OK NC NA HOLD |
| B10 | Bulk Density (kg/m³) Acceptance: 2400±50 kg/m³ (normal weight concrete) | Calculate density = Mass / Volume | OK NC NA HOLD |
| C. TEST RESULTS | |||
| C1 | Cross-Sectional Area (mm²) Acceptance: 22500 ± 600 mm² for 150 mm cube | Calculate from measured cube dimensions: L × W (mm²) | OK NC NA HOLD |
| C2 | Maximum Load Applied (kN) Acceptance: Within machine capacity and digital display range | Record peak load from testing machine at failure | OK NC NA HOLD |
| C3 | Compressive Strength (MPa) Acceptance: Result in MPa (typically 20-50 MPa for M25-M50 grades) | Calculate: Strength = Load (N) / Area (mm²) | OK NC NA HOLD |
| C4 | Individual Cube Result (Pass/Fail) Acceptance: Individual ≥ (fck - 3) MPa (e.g., M25: ≥22 MPa) | Compare individual strength vs IS 456 Table 11 lower limit | OK NC NA HOLD |
| C5 | Cube #2 - Compressive Strength (MPa) Acceptance: See C4 acceptance criteria | Second cube test result | OK NC NA HOLD |
| C6 | Cube #3 - Compressive Strength (MPa) Acceptance: See C4 acceptance criteria | Third cube test result | OK NC NA HOLD |
| C7 | Average of 3 Cubes (MPa) Acceptance: Average ≥ fck + 0.825×SD or fck+3 MPa, whichever higher (e.g., M25: ≥28 MPa assuming 4 MPa SD) | Calculate: (C1 + C2 + C3) / 3 | OK NC NA HOLD |
| C8 | Standard Deviation of Set (MPa) Acceptance: Typically 1.5 to 5 MPa for quality control | Calculate SD from 3 cube results if available | OK NC NA HOLD |