Unformatted text preview: Name ______________________________ Student Number ______________________________ Department of Building, Civil & Environmental Engineering BCEE 345 – Structural Design II (Reinforced Concrete Design) Second Midterm Exam Winter 2007 Dr. K. Galal Duration of examination: 11:45 am to 1:00 pm This examination paper includes 3 questions in 3 pages. You are responsible for ensuring that your copy of the paper is complete. Bring any discrepancy to the attention of your invigilator. Special Instructions: 1- This is a CLOSED BOOK exam with the exception that students will be allowed to use an unmarked copy of the design standard CSA A23.3 i.e. PART I of the “Concrete Design Handbook”. The rest of the handbook should not be used. 2- This exam is for a total of 100 points. 3- Attempt ALL THREE questions. 4- The use of any programmable calculator is not allowed. 5- Use information provided. 6- If given data is not sufficient, assume reasonable values for any additional needed information. 7- State clearly all assumptions made. 8- This examination paper must be returned. Design aids: ⎛ 2 K r ⎞ α 1φ c f c′ ⎟ ▪ ρ = ⎜1 − 1 − ⎜ α 1φc f c′ ⎟ φ s f y ⎝ ⎠ φ s ρf y ⎞ ⎛ ▪ K r = φ s ρf y ⎜1 − ⎜ 2φ α f ′ ⎟ ⎟ c 1 c⎠ ⎝ ▪ ≤ ρ max = α 1 β1φ c f c′ ⎛ 700 ⎜ φ s f y ⎜ 700 + f y ⎝ ⎞ ⎟ ⎟ ⎠ Mr = bd 2 × 10 −6 Kr ▪ s ≥ 1.4 db , ≥ 1.4 amax , ≥ 30 mm ▪ min. clear cover to the outside of stirrups: 40mm (exposed), and 30mm (non-exposed) ▪ Note: Areas and diameters of reinforcing rebars are in page 220 of the Concrete Design handbook Continued on page 2 2 Problem 1: [40 points] The following figure shows the top plan view of a floor that is supported by three RC beams. Section X-X shows the dimensions and reinforcement of the beam along axis B. It is required to calculate the factored moment resistance, Mr, of the beam along axis B. Data: fc' = 25 MPa; fy = 400 MPa; Interior exposure; amax = 25 mm; 10M stirrups; 400x400 columns.
A h = 600 mm 100 B C 1 10-30M
400 6000 mm 400 2 1500 mm 1500 mm Section X-X
X X [Hint: No need to check minimum reinforcement, crack control, horizontal spacing between rebars, and skin reinforcement]
400 Problem 2: [35 points] The following figure shows the cross-section of a RC T-beam. The beam has U-shaped 10M stirrups at a uniform spacing of 200 mm.  It is required to calculate the factored shear capacity, Vr, of the beam.  If the factored shear force at the critical section, Vf , is equal to 300 kN, check the adequacy of the shear resistance of the beam. Check if the 200 mm spacing meets the code requirements for maximum spacing between the stirrups. [Hint: If the web reinforcement is not sufficient, no need to provide a revised design]. 500 h = 600 mm Data: fc' = 30 MPa; fy = 400 MPa. 300
Continued on page 3 d = 510 mm 3 Problem 3: [25 points] Section Y-Y shows the cross-section of the continuous beam A-B-C-D at the mid-span of panel BC. The instantaneous deflections at the mid-span of the panel B-C due to service dead load and total load are 4.0 mm and 10.0 mm, respectively. It is required to:  Calculate the instantaneous deflection due to service live load.  Check long-term deflection at the mid-span of panel B-C according to the CSA A23.3-04 deflection limitations, given that partitions were installed after 3 months of removing the shoring and that 25% of the live load is sustained. Note that partitions are likely to be damaged by large deflections.  Comment on the results, and suggest solutions to meet the code requirements without changing the concrete dimensions of the elements. Y A B
Columns 300x300 mm Y C D 6.00 m 6.00 m 6.00 m h = 600 mm 300 Section Y-Y The End Best wishes
Continued on page 4 d = 510 mm ...
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This note was uploaded on 03/11/2009 for the course ENGR BCEE 345 taught by Professor Drgala during the Winter '07 term at Concordia Canada.
- Winter '07
- Environmental Engineering