prestressed concrete beam of section 250 mm wide by 600 mm deep is used over an effective span 10 m to support an imposed load of 8 kN/m. If the unit weight of concrete is 25 kN/m³, find the agnitude of: (a) the concentric prestressing force necessary for zero stress at the bottom fibre at the midspan section when the beam is fully loaded. (b) the eccentric prestressing force of the tendon located at 200 mm from the soffit of the beam that would nullify the flexural stress due to the combined dead and imposed load. (c) Discuss the implication of the results in (a) and (b) above.

prestressed concrete beam of section 250 mm wide by 600 mm deep is used over an effective span 10 m to support an imposed load of 8 kN/m. If the unit weight of concrete is 25 kN/m³, find the agnitude of: (a) the concentric prestressing force necessary for zero stress at the bottom fibre at the midspan section when the beam is fully loaded. (b) the eccentric prestressing force of the tendon located at 200 mm from the soffit of the beam that would nullify the flexural stress due to the combined dead and imposed load. (c) Discuss the implication of the results in (a) and (b) above.

Principles of Foundation Engineering (MindTap Course List)

8th Edition

ISBN:9781305081550

Author:Braja M. Das

Publisher:Braja M. Das

Chapter14: Sheet-pile Walls

Section: Chapter Questions

Problem 14.11P

See similar textbooks

Similar questions

A prestressed concrete beam 200 mm wide and 300 mm deep, is used over an effective span of 6m to support an imposed load of 4 kN/m. The density of concrete is 24kN/m3. At the quarter span section of the beam, find the magnitude of: a) the concentric prestressing force necessary for zero fiber-stress at the soffit when the beam is fully loaded.b) the eccentric prestressing force located 100 mm from the bottom of the beam which would nullify the bottom fiber stress due to loading.
A 5-m simply-supported beam supports a uniformly distributed load equal to 40 kN/m applied throughout the beam. What is the maximum flexural stress if the beam has a triangular cross-section with b = 300 mm and h = 600 mm? (in MPa)
A prestressed concrete beam 400 mm x 800 mm is to carry auniform load of 40 kN/m on a simple span of 11 m. the beam is prestressed to2200 kN applied 200 mm below the neutral axis.a) Which of the following most nearly gives the stress at the bottom of thebeam at midspan.b) Which of the following most nearly gives the stress at the top of the beamat midspan.c) If a concentrated load P is to be applied at midspan, which of the followingmost nearly gives the the value of P so that the stress at the bottom of thebeam at midspan becomes zero.
A 5 m simply supported beam supports a uniformly distributed load equal to 40 kN/m applied throughout the beam. What is the minimum flexural stress if the beam has a triangular cross section with b= 300 mm and h = 600 mm? (in MPa)
A prestressed rectangular beam 500x750mm has a simple span of 30m and is loaded by a uniform load of 4.5 kN/m including its own weight. The prestressing tendon is 225mm from the bottom and produces an effective prestress of 1600 kN. A.Compute the fiber stress distribution at the bottom of the concrete mid section due to the loads in kPa. B.Compute the fiber stress distribution at the bottom of the concrete mid section due to axial force in kPa. C.Compute the fiber stress distribution at the top of the concrete mid section due to prestress eccentricity in kPa D.Compute the fiber stress distribution at the top of the concrete mid section due to the loads in kPa E. Compute the total stress at the bottom of the concrete mid section in kPa. F.Compute the total stress at the top of the concrete mid section in kPa.
The channel section carries a uniformly distributed load totaling 6W and two concentrated loads of magnitude W. Determine the (a) location of the neutral axis from the bottom, (b) the moment of inertia about that axis, (c) the maximum allowable value for W if the working stress are 4.0 MPa in tension, 8.0 MPa in compression, and 2.4 MPa in shear.
. A pre-stressed concrete beam 200 mm wide and 300 mm deep is used over an effective span of 6 m tosupport an imposed load of (8+24) kN/m3. at mid span section;a) Find the concentric pre-stressing force necessary for zero fiber stress at the soffit of the beam when itis fully loaded.b) Find the eccentric pre-stressing force necessary for the stress to be zero at the bottom if eccentric prestressing force is located at 100mm from the bottom of the beam.
A 360 mm thick footing slab supports a 300 mm thick wall carrying uniform service dead load of 264.7 kN/m and service live load of 111 kN/m. The base of the wall footing slab is 1.1 m from the ground surface. Use 16 mm diameter for main bars. Design parameters are as follows: γsoil = 18 kN/m3, γconc = 24 kN/m3, qa = 233.2 kPa, f’c = 27 MPa and fy = 414 MPa. Calculate the allowable nominal beam shear stress in MPa. Express your answer in 3 decimal places.
The floor of a wholesale store building is made of 100 mm thick cinder concrete. If the floor is a slab having a length of 3m and width of 2.5m, determine the resultant force in kN caused by the dead load and the live load.
In a reinforced beam having a width of 300 mm and an effective depth of 600 mm, carries a moment of 80 KN m which developed a maximum stress of 5 MPa in the concrete. Determine the area of steel reinforcement required if n = 9. What stress is developed in the steel?
A 5-m simply-supported beam supports a uniformly distributed load equal to 40 kN/m applied throughout the beam. What is the maximum flexural stress if the beam has a rectangular cross-section with b = 300 mm and h = 600 mm? (in MPa) answer in 3 decimal places
The simple beam carries a concentrated load P = 15kN. Dimension a and b are 2.5m and 1.2m. respectively. What is the required section modulus of the beam, in mm^3, if the stress is 120Mpa?