Excellent

Q.I/ 25% The one-way slab system with three consecutive spans, 27 ft center-to-center. The slab is supported on 2-ft wide beams. Unbonded tendons are specified and given the following information: normal weight concrete ϒc = 150 pcf, fc’= 5,000 psi, fci’= 3,500 psi, Ec = 4.287×106 , minimum concrete cover to the centroid of the prestressed reinforcement = 1.25 in. The tendons are strands with fpu = 270 ksi, fpe = 160 ksi. A uniform live load of 100 psf is prescribed. Note: assume any data that you think is missing. 1-design the prestressing tendons. 2- check the effect of unbalanced load for an exterior span. Q.II/ 25% A simply supported beam has a span of 66’, the section to be used is Double Tee 10’- 0” x 32” Normal weight concrete with 2” topping. fc’= 5,000 psi, fci’= 3,500 psi and fpu = 270 ksi. The diameter of the strand is 0.5”, the super imposed live load is 0.8 klf. 1- Determine the required no. of strands and the no. of depressed points? 2- What is the estimated long-term camber. What will be that camber if the superimposed live load is included? Q.III/ 25% A cylindrical wall for a water tank, with 2’ free board, has a total height of 36’ and an interior radius of 72’. The tank is assumed to have a free sliding base. Concrete: fc’= 5,000 psi; fci’= 4,000 psi; ftc’ = -283 psi; ; σci = 2,000 psi; σcs = 1,500 psi; Ec = 4230 ksi; Eci = 3834 ksi; np = 6.54. Steel: fpu = 270 ksi; fpi = 190; ksi fpe = 150 ksi; fpy = 243 ksi Determine: 1- Minimum wall thickness and prestressing steel area. 2- Safety against cracking. Q.IV/ 25% A railway bridge having the following section shown. The bridge is a composite section with prestressed posttensioned girders spaced 57” center to center. The compressive strength for the deck slab and the girder is 3,500 psi and 5,500 psi, respectively. The simply supported span is 110’. Design a section located10’ from the left support for shear where Vd ,Vl , Md ,and Ml are 130 kips,150 kips,1300 kip-ft and 1500 kip-ft, respectively.