Singly Reinforced Sections · Reinforced Cement Concrete · GATE CE
Marks 1
In the context of elastic theory of reinforced concrete, the modular ratio is defined as the ratio of

At cross-section $$XX,$$ which of the following statements is TRUE at the limit state?
Marks 2
Consider a reinforced concrete beam section of 350 mm width and 600 mm depth. The beam is reinforced with the tension steel of $800 \mathrm{~mm}^2$ area at an effective cover of 40 mm . Consider M20 concrete and Fe415 steel. Let the stress block considered for concrete in IS 456:2000 be replaced by an equivalent rectangular stress block, with no change in (a) the area of the stress block, (b) the design strength of concrete (at the strain of 0.0035), and (c) the location of neutral axis at flexural collapse. The ultimate moment of resistance of the beam (in kN.m) is __________ (round off to the nearest integer).
Consider a reinforced concrete beam section of 300 mm width and 700 mm depth. The beam is reinforced with the tension steel of $2000 \mathrm{~mm}^2$ area at an effective cover of 50 mm . Concrete in the tension zone is assumed to be cracked. Assume the modular ratio of 12 and Young's modulus of 200 GPa for steel. When the extreme fibre in the compression zone undergoes the strain of 0.0004 due to the applied bending moment, the stress in the steel (in MPa ) is _________ (rounded off to the nearest integer).
Consider the singly reinforced section of a cantilever concrete beam under bending, as shown in the figure (M25 grade concrete, Fe415 grade steel). The stress block parameters for the section at ultimate limit state, as per IS 456: 2000 notations, are given. The ultimate moment of resistance for the section by the Limit State Method is ________ kN.m (round off to one decimal place).
[Note: Here, As is the total area of tension steel bars, b is the width of the section, d is the effective depth of the bars, fck is the characteristic compressive cube strength of concrete, fy is the yield stress of steel, and xu is the depth of neutral axis.]


Adopt the stress block for concrete as given in $$IS$$ $$456$$-$$2000$$ and take limiting value of depth of neutral axis as $$0.48$$ times the effective depth of the beam.
The limiting value of the moment of resistance of the beam in $$kN$$-$$m$$ is
Adopt the stress block for concrete as given in $$IS$$ $$456$$-$$2000$$ and take limiting value of depth of neutral axis as $$0.48$$ times the effective depth of the beam.
The limiting area of tension steel in $$m{m^2}$$ is
The depth of neutral axis for the balanced failure is
$$1.\,\,\,\,\,\,$$ The width-to-thickness ratio limitations on the plate elements under
$$\,\,\,\,\,\,\,\,\,\,\,$$ compression in steel members are imposed by $$IS:$$ $$800$$ - $$1984$$ in order to avoid
$$\,\,\,\,\,\,\,\,\,\,\,$$ fabrication difficulties.
$$2.\,\,\,\,\,\,$$ In a doubly reinforced concrete beam, the strain in compressive reinforcement is
$$\,\,\,\,\,\,\,\,\,\,\,$$ higher than the strain in the adjoining concrete.
$$3.\,\,\,\,\,\,$$ If a cantilever $${\rm I}$$-section supports slab construction all along its length with
$$\,\,\,\,\,\,\,\,\,\,\,$$ sufficient friction between them, the permissible bending stress in compression
$$\,\,\,\,\,\,\,\,\,\,\,$$ will be the same as that in tension.
The TRUE statements are
At the limiting state of collapse in flexure, the force acting on the compression zone of the section is
Ignoring the presence of tension reinforcement, the value of load $$P$$ in $$kN$$ when the first flexure crack will develop in the beam is
The theoretical failure load of the beam for attainment of limit state of collapse in flexure is
$${\rm I}.\,\,\,\,\,\,\,\,\,\,\,\,$$ Maximum strain in concrete at the outermost compression fibre is taken to be $$0.0035$$ in bending
$${\rm II}.\,\,\,\,\,\,\,\,\,\,\,\,$$ The maximum compressive strain in concrete in axial compression is taken as $$0.002$$ Keeping the provisions of $$IS$$ $$456$$-$$2000$$ on limit state design in mind, which of the following is true?
$${\rm I}.\,\,\,\,\,\,\,\,\,\,\,\,$$ Failure takes place by crushing of concrete before the steel has yielded.
$${\rm II}.\,\,\,\,\,\,\,\,\,\,$$ The neutral axis moves up as the load is increased.
With reference to the above statements, which of the following applies?

A rectangular under-reinforced concrete section of $$300$$ $$mm$$ width and $$500$$ $$mm$$ effective depth is reinforced with $$3$$ bars of grade $$Fe$$-$$415,$$ each of $$16$$ $$mm$$ diameter. Concrete mix is $$M20.$$
The depth of the neutral axis from the compression fibre is

A rectangular under-reinforced concrete section of $$300$$ $$mm$$ width and $$500$$ $$mm$$ effective depth is reinforced with $$3$$ bars of grade $$Fe$$-$$415,$$ each of $$16$$ $$mm$$ diameter. Concrete mix is $$M20.$$
The depth of the neutral axis obtained as per $$IS:$$ $$456$$-$$2000$$ differs from the depth of neutral axis obtained in $$Q.08$$ by