Reference no: EM133112755
Question: A 150 mm thick reinforced concrete slab is supported on all 4 sides as denoted in the diagram.
• The design moment capacities are
ΦMux+
|
10 kNm/m
|
ΦMux-
|
12 kNm/m
|
ΦMux+
|
15 kNm/m
|
ΦMux-
|
18 kNm/m
|
• All reinforcing is Grade N.
• Permanent load (DL) and imposed load (LL) factors are as given in Lecture 1.
• In addition to the self-weight there is a nominal permanent load of 1 kPa for permanent partitions.
• Reinforced concrete nominal density is as given in Lecture 1.
Show all working (including differentiation for the yield-line method).
Question 1: If the slab is supported on all 4 sides as denoted in the diagram, use published coefficients that apply only to ductile rectangular slabs with standard support conditions and uniform loading in AS 3600 to calculate the nominal value of uniformly distributed imposed load (LL) that the slab can support.
Question 2: If the slab is supported on 4 sides as denoted in the diagram, use yield-line theory to calculate the nominal value of uniformly distributed imposed load (LL) that the slab can support. [Additional information: The distance in the x direction from the left edge (the simply supported edge) to an intersection point of yield-lines is 1.747 m].
Question 3: If the slab is supported on 4 sides as denoted in the diagram, use the strip method to calculate the nominal value of uniformly distributed imposed load (LL) that the slab can support. For the strip method distribute the total load 30% spanning in the long direction and 70% spanning in the short direction, and calculate the moments in the strips using elastic analysis.
Question 4: If the slab is simply supported on 4 sides (instead of supported as denoted in the diagram), use yield-line theory to calculate the nominal value of uniformly distributed imposed load (LL) that the slab can support.
Question 5: In 100 words or less, explain why the 4 values for the nominal value of uniformly distributed imposed load (LL) that the slab can support are different.