| S.No. | Checkpoint | IS Requirement | Status |
|---|---|---|---|
| A. SAMPLE PREPARATION | |||
| A1 | Mortar samples collected during laying; 9 cubes (70.6 mm) prepared per batch Acceptance: Standard moulds; 2 layers, 32 blows per layer; 3 cubes each for 7-day and 28-day testing | Cl. 4 — Specimen preparation | OK NC NA HOLD |
| A2 | Cubes cured in moist condition at 23±2°C until testing Acceptance: Moist curing chamber; temperature 23±2°C; humidity >90%; no disturbance | Cl. 4.1 — Curing procedure | OK NC NA HOLD |
| B. 7-DAY TESTING | |||
| B1 | Cubes tested at exactly 7 days; surface-dried before testing Acceptance: Age ±30 min from 7 days; wiped dry; room temperature 20-27°C | Cl. 5 — Testing age | OK NC NA HOLD |
| B2 | Load applied at 0.6-1.2 MPa/s until failure; load recorded to 0.1 kN Acceptance: Constant rate; proper centering; 3 cubes tested; failure recorded | Cl. 5.1 — Loading rate | OK NC NA HOLD |
| B3 | 7-day strength calculated and average determined Acceptance: Strength = Load / Area; average of 3 cubes; typical 3.5-5 MPa for 1:3 mortar | Cl. 6 — Calculation | OK NC NA HOLD |
| C. 28-DAY TESTING | |||
| C1 | Cubes tested at exactly 28 days from casting Acceptance: Age ±30 min from 28 days; properly cured; dry before testing | Cl. 5 — Testing age | OK NC NA HOLD |
| C2 | Load applied at constant rate until failure Acceptance: Rate 0.6-1.2 MPa/s; 3 cubes tested; failure load recorded | Cl. 5.1 — Loading procedure | OK NC NA HOLD |
| C3 | 28-day strength calculated; average determined Acceptance: Strength = Load / Area; typical 10-15 MPa for 1:3 mortar; minimum per spec | Cl. 6 — Calculation | OK NC NA HOLD |