Mansoura UniversityFaculty of EngineeringStructural Eng. Dept. ( Reinforced Concrete - 3 )

4th Year CivilDate: June 2014Time: 4 hours

Notes: 1. Any missing data is to be reasonably assumed.2. Design Aids can be used ( including PCA Tables ).3. Total grade is 100 points.4. The Exam consists of 2 pages.

Question 1: (25 Points)It is required to design a circular elevated tank with central column of diameter

900 mm and the column capital diameter of 2000 mm. The internal diameter of thetank is 10 m and the internal height is 5 m. Use concrete with!cll = 30 MPa and steel240/350. Draw to scale 1:50 the details of reinforcement.

Question 2: (25 Points)Design the walls and the floors of a rectangular elevated tank rested on two T-

frames spaced 6.0 m. The height of the tank walls is 4.25 m. The length of the flooris equal to 11.0 m and the width of the floor is equal to 5.0 m. Use steel 400/600 and

!ell = 25 N/mm2. Draw to scale) :50 the details of! einforcement.

Question 3: (IS Points)Design the covering cone of the reinforced concrete tank shown in the

following figure. Use steel 360/520 and concrete with !ell = 35 N/mm2. Draw to asuitable scale the deta.ils of reinforcement of the covering cone.

t_ 0 - 24••0 m1----

Eoc:-.,i

o ~11.0 m J-'1

Question 4: (15 Points)Design a cantilever beam of span 3.30 m using the Ultimate Limit State

Method. Assume that the cross-section of the beam is rectangular with dimensions350 mm * 1450 mm. The total ultimate uniform load of the beam is 85.0 kN/m. Theservice load is 55.0 kN/m from which 20 kN/m is sustained dead load and 15 kN/mdue to finishes and partitions. Use concrete with characteristic compressive strength30 N/mm2 and steel 360/520. Check the limit state of cracking.

Question 5: (15 Points)A longitudinal section of a post-tensioned prestressed concrete beam is shown

in Fig.3. has a constant rectangular section ( OAx1.5 m ) and an initial prestressingforce Fo = 300 ton, if the losses = 15 % , ( fei= 135 kg/ern' , fti= 12 kg/ern' ,f" = '4f\ lr~/~~2 +' - 2? kz/cm'' \ v•.is reauired •.•....-cw 1. V l\..c'! ~lU , ·I.tw - v 6' ~lU J ..•. II.. • ••••• """

i. Find the allowable length of the beam L = ? m.ii. Find the maximum allowable live load p = ? t/m' .iii. Check the normal stresses of section (B) at final stage.

~ 0.4

--- -------- ._._._._o_.o_o_.~._._o._._._o_o o_._. --'f'-~':::--'-~'--"'*-~ ~0.~6 --~

A1 O.5_L_o__ o-+- __ 0_.5L iFig. 3

0.2L

Question 6: (15 Points)The continuous post-tensioned prestressed concrete beam shown in Fig. 4, has aconstant rectangular section ( OAx1.5 m). If the losses = 150/0,, ( fei= 135 kg/ern' ,fti= 12 kg/cm' , few = 140 kg/cm', ftw = 26 kg/ern' ) . It is required to;

00 i. Find the allowable initial prestressing force Fo = ? ton,

rii. Find the maximum allowable live load p = ? t/m'.iii Check the normal stresses of section at mid-span AB in final stage.

0.5 0.50.3 0.6 ~. 0.625 =t- 0.6 0.3b-:f. -~~- ---~~~--}--~

10.0 _jr-__ l_o._o_C-II __ lO_.O_-,--_I_O._O __ D_/A

___ IO_.O__ ~ __ I_O._O__ B_f-+-_.20.0 m i\~_.o_m o-+_o. _

.\?igo 4

Best wishes,Prof. Dr. Ahmed Yousef

Dr. Awad El-Mansy