Building Technology, Structures, and Construction Materials
This section combines three examined subjects: how a building stands up, what it is made of, and how it is assembled. In the Iranian exam they map onto مبحث ۶ (loads), مبحث ۸ (masonry), مبحث ۹ (concrete), مبحث ۱۰ (steel), مبحث ۵ (materials) and استاندارد ۲۸۰۰ for seismic behaviour.
Core rules
- Follow the load path: slab → beam → column or shear wall → foundation → soil. A break in the path is a wrong answer even if every member is individually sized correctly.
- Load types: dead (self-weight and finishes), live (مبحث ۶: residential floors about 2.0 kN/m², corridors and stairs higher), snow, wind, earthquake.
- Common factored combination in Iranian practice is 1.25D + 1.5L, with seismic combinations checked separately.
- Span economics: تیرچهبلوک to roughly 6 m, solid slabs for short spans, beam-and-column frames beyond that.
- Concrete is commonly C25 with AIII rebar; cover, curing and vibration control are examined as much as strength.
- Masonry needs کلاف horizontal and vertical at corners and openings, with مبحث ۸ limits on height and wall length.
Worked example
Estimate a 25 cm تیرچهبلوک floor: joist and block ≈ 0.32 t/m², floor finish ≈ 0.11 t/m², ceiling plaster ≈ 0.04 t/m², giving dead load ≈ 0.47 t/m² ≈ 4.6 kN/m². With 2.0 kN/m² live load: 1.25(4.6) + 1.5(2.0) = 5.75 + 3.0 = 8.75 kN/m² design load. The reasoning matters: the finish and ceiling are part of dead load, and partitions must be added if they are not shown on the plan.
Traps
- Mixing kgf and kN.
- Omitting self-weight of the slab or the partition allowance.
- Treating a designed load-bearing wall as infill in the detailing.
- Using span/depth rules without a deflection check on long spans.