DESCRIPTION DATA A prestressed concrete simply supported beam of section 120 mm wide by 300 mm deep will be spanning 6 meters. The beam should be carrying a uniformly distributed live load of 4 kN/m. If the said beam is prestressed by a straight cable carrying a force of 180 kN at an eccentricity of 50 mm. 1. Determine the stresses calculation and diagram for top and bottom extreme fibres. 2. Explain whether the beam can safely carry the live load. 3. If the maximum eccentricity is 50 mm, calculate the maximum Prestress force to produce a negative stress diagram.

A prestress concrete beam of section 200 mm wide and 300 mm deep is used over an effective span of 6m to support an imposed load of 4kN/m. The density of concrete is 24 kN/m3. Find the   (a) The dead load moment (Mg) in kNm shall be equals to (b) The live load moment (Mq) in kNm shall be equals to (c) Tensile stress at the bottom fibre due to live and dead loads in N/mm2 is (d) At the centre of span section of the beam,find the magnitude of the concentric prestressing force in kN neccesary for zero fibre-stress at the soffit when the beam is fully loaded. (e) At the centre of span section of the beam,find the magnitude of the eccentric prestressing force in kN located 100 mm from the bottom of the beam which would nullify the bottom fibre stress due to loading.

Question 5 A rectangular presressed concrete beam of span 15 m and width 500 mm is loaded with a live load of 30 kN/m. The prestressing force is KN. [Take permissible stresses in concrete and steel as 15 MPa and 1200 MPa respectively]

Problem 1 The members of the truss shown below are of plain concrete. The compressive cylinder strength of concrete is 30 MPa. Determine whether the structure can carry the applied load. 31 KN 24 KN D 120x120mm 40x40mm 40x40mm 120x120mm 300 mm 40x40mm 400 mm

A beam having a width of 500 mm and a total depth of 800mm is reinforced with 6-32mm dia bars, Compressive strength of concrete is 28 MPa and yield strength of reinforcing bars is 420MP.. 640 mm 800 mm 6 #32 80 mm 80 mm Determine the following: 1. depth of the compression block 2. strain in the tension reinforcement 3. moment reduction factor 4. nominal moment capacity 5. ultimate moment capacity 6. actual steel ratio 7. minimum steel ratio 8. maximum steel ratio 9. Tension force 10. Compression force

The end block of a post-tensioned beam is 100 mm x 150 mm. A prestressing cable consisting of 7 wires of 6 mm dia strand and stressed to 800 MPa has to be anchored at the center of the block. The anchorage plate is 75 mm x 75 mm. If the concrete mix is M45 and the permissible bending stress in M. S. steel plate is 165 MPa, determine the thickness of the anchorage plate.

Three high-strength concrete poles, with an effective cross- sectional area of 40, 000m * m ^ 2 and a length of 2 m, support a stiff steel plate. The center post is 1 mm shorter than the others before the load P is applied. If the concrete's allowed compressive stress is 20 MPa, calculate the maximum load that can be carried. E = 30GPa for concrete

The concrete post is reinforced axially with four symmetrically placed steel bars, each of cross-sectional area 900 mm2. Compute the stress in each material when the 1000-kN axial load is applied. The moduli of elasticity are 200 GPa for steel and 14 GPa for concrete. Compatibiltiy Equation . Ust Bearing |1000 kN plate Steel- Concrete 300 mm 300 mm Section a-a

Question A pre-stressed concrete beam has a width of 200 mm and an overall depth of 400 mm. The permissible stresses in tension and compression due to pre- stressing alone are 4 N/mm and 25 N/mm respectively. Find the required pre- stressing force in the tendon and the eccentricity of the tendon, if a straight tendon with a constant eccentricity is to be provided in the beam. No external load or self weight effect is to be considered.

A simply supported beam 300 mm wide, 500 mm deep and spans 6 m supports a service super imposed dead load of 10 kN/m and service live load of 6 kN/m.  Concrete strength f’c = 21 MPa and steel yield strength fy = 415 MPa.  Concrete cover to bar centroid is 70 mm.  Determine the type of failure when ultimate loading is applied.   A. Tension Controlled   B. Transition Failure   C. Compression Controlled   D. Balanced Strain Failure