Torsion

Question 1

The ___________ is largely
subjected to torsion, some bending
and shear due to own weight.

Answer 1

cantilever member

Question 2

______ subjected to torsion, in
combination with bending and shear.

Answer 2

RC members

Question 3

The __________ is subjected to
substantial amounts of bending,
shear and torsion.

Answer 3

fixed-ended beam

Question 4

Spandrel beams at the edge of a building built integrally with the
floor slab are subjected not only to __________ but also to a
torsional moment per unit length equal to the restraining moment at
the exterior end of the slab.

Answer 4

transverse loads

Question 5

__________ receive torsional moments from the
exterior ends of the floor beams that frame into them.

Answer 5

spandrel girders

Question 6

Torsion on structural systems may be classified into two types:

Answer 6

statically determinate torsion (“equilibrium torsion”)
Statically indeterminate torsion (compatibility torsion”)

Question 7

Torsion can be determined from statics alone

Answer 7

statically determinate torsion

Question 8

Torsion cannot be determined from statics alone and a ________ is
required for deformational compatibility between interconnecting elements, such as a spandrel beam, slab, or column.

Answer 8

Statically indeterminate torsion , rotation (twist)

Question 9

Linear interpolation
between 0.75 and 0.85 shall be permitted, on the basis of _______, when a portion of
the lightweight fine aggregate is replaced with normal weight fine aggregate.

Answer 9

volumetric fractions

Question 10

Linear interpolation between ____ and ______ shall be permitted, on the basis of volumetric fractions, for concrete
containing normal weight fine aggregate and a blend of lightweight and normal weight coarse
aggregates.

Answer 10

0.85 and 1.0

Question 11

Torsion occurs appreciably in many structures, such as in the main
girders of bridges, which are twisted by ______ beams or slabs.

Answer 11

transverse

Question 12

If a plain concrete member is subjected to pure torsion, it will
crack and fail along ________ due to diagonal tension
corresponding to the torsional stresses.

Answer 12

45° spiral lines

Question 13

Maximum shears and torsional forces may occur in areas where
bending moments are _____.

Answer 13

small

Question 14

_______ is assumed to occur when the principal tensile stress reaches 0.33A.

Answer 14

Cracking

Question 15

In a __________ loaded with torsion alone, the
principal tensile stress is equal to the torsional shear stress,

Answer 15

nonprestressed beam

Question 16

For a statically determinate structure, there is only one path along which a
torsional moment can be transmitted to the supports. T or F

Answer 16

T

Question 17

The _________ in a particular part of a statically indeterminate
structure may be substantially reduced if that part of the structure cracks
under torsion and/or rotates.

Answer 17

torsional moment

Question 18

__________, in the sense that part of structure in
question twists in order to keep the deformations of the structure
compatible.

Answer 18

compatibility torsion

Question 19

When appreciable torsion is present, it may be more economical to
select a _______ than would normally be selected so that torsional
reinforcement does not have to be used.

Answer 19

larger beam

Question 20

The _________ adds to the shear stress on one side of
a member and subtract from them on the other.

Answer 20

torsional stress

Question 21

Torsional stresses are quite low near the ______ of a
solid beam.

Answer 21

center

Question 22

_________ are assumed to
have almost exactly the same torsional strengths as solid
beams with the same outside dimensions

Answer 22

hollow beams

Question 23

The tension cracks tend to spiral around members located at
approximately ______angles with the longitudinal edges of those members.

Answer 23

45°

Question 24

Torsion is assumed to be resisted by an imaginary ___________ located in
the outer tube of concrete of the member.

Answer 24

space truss

Question 25

torsional strength of reinforced concrete beams can be
greatly increased by adding __________ consisting
of closed stirrups and longitudinal bars.

Answer 25

torsional reinforcement

Question 26

It shall be permitted to take 0 equal to 45° for
_________ members.

Answer 26

nonprestressed

Question 27

The longitudinal reinforcement required for torsion must be
distributed around the inside perimeter of the closed stirrups with a
maximum spacing of ________.

Answer 27

300 mm

Question 28

Longitudinal bars shall
have a diameter at least ______times the stirrup spacing, but not less
than No. 10.

Answer 28

0.042 ,

Question 29

Torsional reinforcement must be provided for a distance not less than
_______ beyond the point where it is theoretically no longer required.

Answer 29

bt + d