Slab Design
Reinforced concrete slabs are flat, horizontal structural elements that transfer loads to beams, columns, or walls. Slabs can be one-way (spanning in one direction) or two-way (spanning in both directions). Design considerations include flexural reinforcement, shear resistance, deflection control, and crack control. The minimum thickness for deflection control is specified in building codes. One-way slabs are designed as wide, shallow beams, while two-way slabs utilize the direct design method or equivalent frame method.
Knowledge Check
1.A simply supported one-way slab spans 4.5 m. What is the minimum thickness for deflection control? (Use L/20)
2.A two-way slab is supported on all four sides and has a span ratio (L_long/L_short) greater than 2. This slab should be designed as:
3.In a two-way slab, what is the purpose of the drop panel?
4.The minimum steel reinforcement ratio for temperature and shrinkage in a slab (Grade 60 bars) is:
5.A flat slab system does NOT have:
6.The direct design method for two-way slabs can be used when the spans are approximately equal and the live load is less than:
7.A slab with span length L = 6 m, thickness h = 200 mm, and concrete density = 24 kN/m³. What is the self-weight of the slab per square meter?
8.The maximum spacing of reinforcing bars in a slab is typically limited to:
9.In a ribbed (waffle) slab, the ribs or joists:
10.What is the primary purpose of shrinkage and temperature reinforcement in a slab?