Materials and Building Components
This domain tests acceptance of materials and components at site: sampling, testing, and the decision to accept, reject or retest. The governing documents are Mabhas 5 (materials and products), Mabhas 9 for concrete, and the national standards (استانداردهای ملی ایران) for cement, reinforcement, masonry units and insulation.
What you must control
- Traceability: every delivery needs a certificate of conformity or a test report matching the specification; unlabelled rebar or cement is rejected regardless of appearance.
- Concrete: slump on arrival, sampling frequency tied to volume and to each pour day, cube curing and 28-day compressive strength evaluation.
- Reinforcement: grade and diameter verified against the bar schedule; bending, hook and lap geometry checked before pouring.
- Masonry and finishes: unit strength and absorption, mortar mix, block curing, and the substrate condition before plastering or tiling.
- Insulation and components: thickness and density as specified; damaged boards are not "good enough".
Worked example
Specified concrete class is C25. Three 150 mm cubes give 31, 28 and 26 MPa at 28 days. Average = 28.3 MPa ≥ 25 MPa. Lowest = 26 MPa, which is above a commonly applied floor of 0.85 × 25 = 21.25 MPa. Both conditions satisfied → accept the pour. If instead the results were 30, 26 and 19 MPa, the average 25.0 MPa passes but the 19 MPa cube fails the floor, so the batch is referred for core testing rather than quietly accepted.
Traps
Accepting results from cubes cured on site in the sun. Testing only the strongest cube. Mixing cement types or brands in one structural pour without design approval. Approving plaster on a dusty, uncured substrate because the schedule is tight.