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CONFIDENTIAL AP/OCT 2008/QSD133/103 yplp V5 UNIVERSITI TEKNOLOGI MARA FINAL EXAMINATION COURSE PRINCIPLES OF STRUCTURES COURSE CODE QSD133/103 EXAMINATION OCTOBER 2008 TIME 3 HOURS INSTRUCTIONS TO CANDIDATES 1. This question paper consists of six (6) questions. 2. Answer four (4) questions in the Answer Booklet. Start each answer on a new page. 3. Do not bring any material into the examination room unless permission is given by the invigilator. 4. Please check to make sure that this examination pack consists of: ) the Question Paper ) an Answer Booklet - provided by the Faculty ) a two (2) sheets of Graph Paper - provided by the Faculty DO NOT TURN THIS PAGE UNTIL YOU ARE TOLD TO DO SO This examination paper consists of 7 printed pages © Hak Cipta Universiti Teknologi MARA CONFIDENTIAL CONFIDENTIAL 2 AP/OCT 2008/QSD133/103 QUESTION 1 a) Using suitable sketches explain how loads are transferred from the roof to the foundation. (10 marks) b) Figure Q1b shows a simply supported beam with a cross-section 300mm x 600mm carrying 300mm thick brickwall. i) Calculate the ultimate design load to be resisted by the beam. ii) Calculate the reaction at the support due to the ultimate design load Given: The density of reinforced concrete = 2400kg/m3 The density of brickwall = 2200kg/m3 2.4m 0.6m 3.0m 6.0m Figure Q1b (15 marks) QUESTION 2 a) Using suitable sketches explain how loads are transferred from one way slab and two way slab to the beam. (8 marks) b) Explain the behaviour of short column when loaded with: i) Axial load ii) Eccentric load (7 marks) ) Hak Cipta Universiti Teknologi MARA CONFIDENTIAL CONFIDENTIAL 3 AP/OCT 2008/QSD133/103 c) Determine the unknown reactions at the support, due to the loads carried by the cantilever beam as shown in Figure Q2c. 5kN 10kN/m 20kN/m 0.5m 1.5m 1.0m *-*- Figure Q2c (10 marks) QUESTION 3 a) Explain the following terms i) Resultant force ii) Centroid (6 marks) b) Figure Q3b shows a free body diagram of concurrent force system. Determine the magnitude and direction of the resultant force. y axis 150l\h«- xaxis 45 u 100N 200N Figure Q3b (9 marks) © Hak Cipta Universiti Teknologi MARA CONFIDENTIAL CONFIDENTIAL 4 AP/OCT 2008/QSD133/103 c) Figure Q3c shows a precast concrete block 300mm thick. Determine the position of its centroid from point of reference P. 3m 2.1m 4.5 m 4m Figure Q3c (10 marks) QUESTION 4 a) The cantilever beam shown in figure Q4a is loaded with uniformly distributed load and point loads. Determine the support reaction and draw the shear force and bending moment diagram. 5kN 3kN 1 <- 10kN/m 2.0m -> 1.0m i 1.0m Figure Q4a (8 marks) © Hak Cipta Universiti Teknologi MARA CONFIDENTIAL CONFIDENTIAL 5 AP/OCT 2008/QSD133/103 b) For the beam shown in Figure Q4b, calculate the reaction at support A and B and draw the shear force and bending moment diagrams. 5kN 10kN f 10 kN/m 20kN/m ^ 11 2.0m 3.0m 1.0m 3.0m 2.0m A B Figure Q4b (17 marks) QUESTION 5 a) Figure Q5a shows the cross section of a timber beam. If the permissible bending stress of the timber is 10N/mm2, determine the maximum bending moment that the beam could safely carry. 75mm x 150mm timber beam Figure Q5a (6 marks) © Hak Cipta Universiti Teknologi MARA CONFIDENTIAL CONFIDENTIAL 6 AP/OCT 2008/QSD133/103 b) A short braced column in the situation of mild exposure is required to support an ultimate axial load of 2000kN. i) If the percentage of main steel reinforcement provided is 2%, calculate the size of square column required and choose the appropriate mild steel reinforcement when grade 30 concrete is used. (14 marks) ii) Determine the height of the above column if it is classified as short column. (5 marks) Given: Equation 38 (a) BS8110 N = 0.4 feu (Ag - Asc) + 0.75 Asc fy Areas of round bar reinforcement (mm2) Diameter Number of bars (mm) 1 2 3 4 5 6 7 8 9 20 314 628 942 1256 1570 1884 2198 2512 2826 25 491 983 1474 1966 2457 2946 3439 3932 4423 32 804 1608 2412 3216 4020 4824 5628 6432 7236 40 1257 2513 3770 5027 6283 5740 8796 10053 11310 QUESTION 6 a) Explain the behaviour of the following beams when subjected to loading. i) Simply supported beam ii) Cantilever beam (8 marks) b) A 300 mm wide singly reinforced concrete beam is required to transmit an ultimate bending moment of 550kNm, inclusive its own weight. The beam is made of grade 30 concrete and high yield reinforcement. Using the simplified stress block formulae given in BS8110 (parti), i) Determine the effective depth of the beam. (5 marks) © Hak Cipta Universiti Teknologi MARA CONFIDENTIAL CONFIDENTIAL 7 AP/OCT2008/QSD133/103 ii) Determine the amount of steel reinforcement required. (7 marks) iii) Choose the appropriate reinforcement for the beam and draw the cross-section of the beam. (5 marks) Given: For singly reinforced concrete, K < K' , K = M/fcubd2 K' = 0.156 z = d [0.5 + V(0.25 - K/0.9)] z < 0.95 d As = M/0.87fy z Areas of round bar reinforcement (mm2) Diameter Number of bars (mm) 1 2 3 4 5 6 7 8 9 6 28 57 85 113 142 170 198 226 255 8 50 101 151 201 252 302 352 402 453 10 79 157 236 314 393 471 550 628 707 12 113 226 339 452 565 678 791 904 1017 16 201 402 603 804 1005 1206 1407 1608 1809 20 314 628 942 1256 1570 1884 2198 2512 2826 25 491 983 1474 1966 2457 2946 3439 3932 4423 32 804 1608 2412 3216 4020 4824 5628 6432 7236 40 1257 2513 3770 5027 6283 5740 8796 10053 11310 END OF QUESTION PAPER © Hak Cipta Universiti Teknologi MARA CONFIDENTIAL