Prob.5: A rectangular reinforced concrete beam has dimensions b = 300 mm, d = 530 mm and h = 600 mm, and is reinforced with 3 Ø32 mm bars. Materials strength are fe = 28 MPa, fy= 414 MPa. a) Find the moment that will produce the first cracking at the bottom surface of the beam basing your calculations on Ig. b) Determine the maximum stress in the steel and in the concrete under this Design of Reinforced Concrete Structures moment.

Prob.5: A rectangular reinforced concrete beam has dimensions b = 300 mm, d = 530 mm and h = 600 mm, and is reinforced with 3 Ø32 mm bars. Materials strength are fe = 28 MPa, fy= 414 MPa. a) Find the moment that will produce the first cracking at the bottom surface of the beam basing your calculations on Ig. b) Determine the maximum stress in the steel and in the concrete under this Design of Reinforced Concrete Structures moment.

Materials Science And Engineering Properties

1st Edition

ISBN:9781111988609

Author:Charles Gilmore

Publisher:Charles Gilmore

Chapter12: Composite Materials

Section: Chapter Questions

Problem 12.7P: Estimate the transverse tensile strength of the concrete in Problem 12.6.

See similar textbooks

Similar questions

The point loads are placed at the fixed positions shown in the figure and they are live loads. A k a b a b dn = 1₂ Icr= M B 7 Ast Stress profile (concrete) Cross section before cracking Aso Cross section Asc Ast N.A. Q2) Now, the live load increases gradually and the moment at the critical section just exceeds the cracking moment (Mcr), but the compressive section of the concrete is still under the linear elastic region. Please be reminded that in the flexural design, the crack of the concrete section starts where the tensile stress reaches the tensile strength. It is assumed that the cracks then propagate rapidly up to the entire tension section (up to the neutral axis) and this cracked concrete section cannot resist the tension. It should be noted that in reality, concrete sections between the primary cracks can still resist some tensile stresses as shown in the figure, which should be considered in the displacement design. However, in flexure design, we design the critical section…
A composite beam is made of two brass [E = 106 GPa] plates bonded to an aluminum [E = 60 GPa] bar, as shown. The beam is subjected to a bending moment of 1720 N-m acting about the z axis. Assume b=45 mm, d₁-53 mm, d₂-13 mm. Determine: (a) the maximum bending stresses Obr, Gal in the brass plates and the aluminum bar. (b) the stress in the brass Obrj at the joints where the two materials are bonded together. Brass (2) Aluminum (1) Brass (2) b ↓ d₂ d₁ d₂
A composite beam is made of two brass [E = 97 GPa] plates bonded to an aluminum [E = 72 GPa] bar, as shown. The beam is subjected to a bending moment of 2420 N-m acting about the z axis. Assume b=64 mm, d1=36 mm, d2=13 mm. Determine: (a) the maximum bending stresses opy,Gal in the brass plates and the aluminum bar. (b) the stress in the brass obrj at the joints where the two materials are bonded together. Brass (2) d2 Aluminum (1) Brass (2) dz b Answers: (a) obr = i MPa, oal = i MPа. (b) Obrj MPa.
A composite beam is made of two brass [E = 99 GPa] plates bonded to an aluminum [E = 63 GPa] bar, as shown. The beam is subjected to a bending moment of 2210 N-m acting about the z axis. Assume b=44 mm, d1=28 mm, d2=13 mm. Determine:(a) the maximum bending stresses σbr, σal in the brass plates and the aluminum bar.(b) the stress in the brass σbrjσb⁢r⁢j at the joints where the two materials are bonded together.
A singly reinforced rectangular section has a width of 250mm and an effective depth of 460mm. The concrete has a compressive strength of 21MPa. The steel has a yield strength of 275 MPa and E = 200,000 MPa. Calculate the ideal flexural strength for the following areas of steel: a. 2580 mm² b. 5160 mm² c. The value at balanced failure
1. Differentiate the permanent and the variable action with suitable examples 2. Analyze the stress-strain relationship of steel. Notes : Internal forces Fcc = 0.567fck(b x 0.8x) = 0.454 fck bx Fst = 0.87 fyk As Moment of resistance with respect to steel, M = Fcc.z Moment of resistance with respect to concrete, M = Fst.z Mbal = Kbal fck bd2 where Kbal = 0.167 As ‘ = (M-Mbal) / 0.87 fyk (d-d’) As = Mbal / 0.87 fyk zbal + As’
1. Shown is a composite plate joined together by rivets. The components consist of two tension bar plates that is % X 4 inch and riveted together by two splice plates which is 0.8 X 6 inch. Each rivet has a diameter of 25.4 mm. Considering that the allowable stress for the tension bar plates and splice plates is o=20.0 ksi, the allowable shear stress for the rivets is o=25.0 ksi and the allowable bearing stress on the rivets and splice plates is o=25.0 ksi. What will be the maximum permissible load P such that none of the allowable stresses will be exceeded? Splice Plates a-0.75 in Bar Lc =0.80 in. Bar P d = 1.0 in. b=4.0 in. Rivets 'e = 6.0 in.
Both of the tension and compression forces are exerted on the concrete specimen when investigating the flexural strength. However, the specimen fails due to the flexural forces. * True False Other:
A circular aluminum alloy [E = 70 GPa; a = 22.5 x 10-6/°C; v = 0.33] pipe has an outside diameter of 270 mm, a wall thickness of 15 mm, and a length of 5.5 m. The pipe supports a compressive load of 635 kN. After the temperature of the pipe drops 45°C, determine: (a) the axial deformation of the pipe. (b) the change in diameter of the pipe. Answer: (a) 8 = i AD= i mm mm
An axial centric force of magnitude P = 450 kN is applied to the composite block shown by means of a rigid end plate. Knowing that h = 10 mm, determine the normal stress in (a) the brass core, (b) the aluminum plates. Aluminum plates (E = 70 GPa) 300 mm Brass core (E = 105 GPa) 40 mm h Rigid end plate 60 mm
2. A long steel pipe is subjected to a state of plane strain (ɛzz = Ezx = Ezy = 0) when the design loads are applied. At the critical point in the pipe, the non-zero stress 143.28 MPa , components are found to be oxx = 53.28 MPa , ơyy Oxy 40 MPa and o22 = 57 MPa . The material has a yield stress of = 245 MPa . Determine the factor of safety in the design based on the von Oy Mises criteria.
1) A rectangular reinforced concrete beam with dimensions b = 14 in, d = 25 in, and h = 28 in is reinforced with three No. 10 bars. Material strengths are fy = 60000 psi and fc' = 5000 psi. a. Find the cracking moment based on the uncracked transformed section b. Determine the maximum moment that can be carried without stressing the concrete beyond 0.45fc' or the steel beyond 0.6fy. Hint: Assume maximum compressive stress in the concrete to be 0.45fc' and check whether the maximum steel stress reaches 0.6fy. This way you can check which one is reached first C. Find the nominal moment capacity of the beam