| S.No. | Checkpoint | IS Requirement | Status |
|---|---|---|---|
| REG. CUBE SPECIMEN LIFECYCLE LOG - COLUMN DEFINITIONS | |||
| COL-01 | S.No Acceptance: Sequential numbering from 1 onwards | Serial number for each cube set entry | |
| COL-02 | Cube Set ID Acceptance: Unique across project; linked to Pour Register (QC-CON-REG-001) | Unique identifier for the cube set (e.g., SET-001, CS-P1-001) | |
| COL-03 | Date Cast Acceptance: Same as pour date; time of casting recorded (HH:MM) | Date and time when cubes were cast from the concrete pour | |
| COL-04 | Pour Ref / Element Acceptance: Pour ID or element description matching Pour Register | Reference to the concrete pour (link to QC-CON-REG-001) and element concreted | |
| COL-05 | Grade Acceptance: As per design specification; must match pour grade | Concrete grade (e.g., M25, M30, M40, M50) | |
| COL-06 | Mix Design Acceptance: Approved mix design ID/reference; traceability to proportions | Reference to approved mix design document (IS 10262:2009) | |
| COL-07 | No. of Cubes Acceptance: Typically 6 cubes per set: 3 for 7-day test + 3 for 28-day test (minimum 1 set per 30 m³) | Total number of cube specimens in the set | |
| COL-08 | Mould IDs Acceptance: Calibrated moulds per IS 456, IDs recorded for traceability | Unique identifiers of the 150mm cube moulds used | |
| COL-09 | Curing Method Acceptance: Standard water immersion at 27±2°C or moist sand/cotton bed; per IS 516 | Curing method used for the cubes (e.g., water immersion, moist burlap) | |
| COL-10 | Lab Sent To Acceptance: Accredited testing lab with valid equipment calibration certificates | Name of testing laboratory | |
| COL-11 | Date Sent Acceptance: Documented delivery date; chain of custody maintained | Date cubes were dispatched to the testing lab | |
| COL-12 | 7-Day Test Date Acceptance: 7±1 days from casting date (per IS 516:1959 Clause 6.5) | Date when 7-day compression test was conducted | |
| COL-13 | 7-Day Results - Cube 1 (MPa) Acceptance: Recorded strength in MPa to 0.5 MPa precision | Compressive strength of first cube specimen at 7 days | |
| COL-14 | 7-Day Results - Cube 2 (MPa) Acceptance: Recorded strength in MPa to 0.5 MPa precision | Compressive strength of second cube specimen at 7 days | |
| COL-15 | 7-Day Results - Cube 3 (MPa) Acceptance: Recorded strength in MPa to 0.5 MPa precision | Compressive strength of third cube specimen at 7 days | |
| COL-16 | 7-Day Average (MPa) Acceptance: Mean of Cube 1, 2, 3; calculated value in MPa | Average compressive strength of 3 cubes at 7 days | |
| COL-17 | 7-Day Pass/Fail Acceptance: PASS if average ≥ fck - 3 MPa (tolerance allowance); FAIL if below | Pass/Fail verdict at 7 days (informational; IS 456 primarily uses 28-day for acceptance) | |
| COL-18 | 28-Day Test Date Acceptance: 28±1 days from casting date (per IS 516:1959 Clause 6.5) | Date when 28-day compression test was conducted | |
| COL-19 | 28-Day Results - Cube 1 (MPa) Acceptance: Recorded strength in MPa to 0.5 MPa precision; primary acceptance criterion per IS 456 | Compressive strength of first cube specimen at 28 days | |
| COL-20 | 28-Day Results - Cube 2 (MPa) Acceptance: Recorded strength in MPa to 0.5 MPa precision; primary acceptance criterion per IS 456 | Compressive strength of second cube specimen at 28 days | |
| COL-21 | 28-Day Results - Cube 3 (MPa) Acceptance: Recorded strength in MPa to 0.5 MPa precision; primary acceptance criterion per IS 456 | Compressive strength of third cube specimen at 28 days | |
| COL-22 | 28-Day Average (MPa) Acceptance: Mean of Cube 1, 2, 3; calculated value in MPa. Accept if: Average ≥ (fck + 0.825×SD) AND Each individual ≥ (fck - 3) MPa | Average compressive strength of 3 cubes at 28 days | |
| COL-23 | 28-Day Pass/Fail Acceptance: PASS if both conditions met: (1) Average ≥ (fck + 0.825×SD) AND (2) All individuals ≥ (fck - 3). FAIL if either condition fails; triggers NCR and remedial investigation | Pass/Fail verdict at 28 days (final acceptance criterion per IS 456:2000) | |
| COL-24 | NCR No (if fail) Acceptance: NCR ID linked to defect management system; leave blank if PASS | Non-Conformance Report number if 28-day test failed | |
| COL-25 | Remarks Acceptance: Document concrete appearance, test anomalies, core sampling decision, or remedial measures | Any observations, defects, or actions taken | |
| CRITERIA. ACCEPTANCE CRITERIA REFERENCE (IS 456:2000 Table 11) | |||
| ACC-01 | Individual Cube Strength Acceptance: Each cube ≥ (fck - 3) MPa. If any cube fails, element requires investigation (core testing per IS 1199:1959 Cl. 15) | Each tested cube must achieve minimum strength | |
| ACC-02 | Average Cube Strength Acceptance: Average ≥ (fck + 0.825×SD) where SD = standard deviation of all results in the acceptance group. Typical SD ≈ 2-3 MPa for controlled concrete | Average of 3 cubes must exceed specified threshold | |
| ACC-03 | Sampling Frequency Acceptance: 1 set per 30 m³ (or part thereof); 1 set per day minimum. Set = 6 cubes (3 at 7-day, 3 at 28-day) | Minimum number of cube sets per project phase | |
| ACC-04 | Core Testing Trigger Acceptance: If 28-day cube average < (fck + 0.825×SD) OR any individual < (fck - 3) MPa. Minimum 3 cores per 1000 m² of element surface, 150mm diameter, tested per IS 1199 Cl. 15 | When core testing of in-situ concrete becomes mandatory | |