301. The load carrying capacity of a column designed by working stress method is 500 kN. The collapse load of the column is 750.0 kN
302. Shear span is defined as the zone where shear force is constant
303. Shear cracks start due to high diagonal tension in case of beams with their webs and high prestressing force
304. For ultimate load design of prestressed concrete girders used for bridges,
combination of load factors used is (here DL and LL are dead and live loads
respectively)1.5 D.L.+ 2.5 L.L
305. For a pretensioned rectangular plank the uplift at centre on release of wires from anchors due to pretensioning only (force P, eccentricity e) will be
PeL²/8EI
306.Deflection can be controlled by appropriate
span/depth ratio
307.In limit state approach, spacing of main reinforcement controls primarily
cracking
308. For the section of the beam shown in Fig. 14.2, span of the beam = 6.0 m,
concrete = M20, steel = Fe415.
If the section is checked for serviceability limit state of deflection, then it will be
found that the section is safe
309. Unequal top and bottom reinforcement in a reinforced concrete section leads to shrinkage deflection
310. A pretensioned plank (depth D₁) is placed over simple supports and additional in situ concrete (depth D₂) is laid on top. What is the probable shape of stress block on hardening of in situ concrete?
311.Design of foundation for a large generator is guided primarily, by frequency
312
A concrete pedestal made of M20 mix is shown in Fig. The tan a value in this
case will be grater than or equal to 3.6
313. The reduction coefficient of a reinforced concrete column with an effective length of 4.8 m and size 250 x 300 mm is 0.85
314.Given that
d = effective depth
b = width and
D = overall depth
the maximum area of compression
reinforcement in a beam is 0.04 bD
315.The final deflection due to all loads including the effects of temperature, creep
and shrinkage and measured from as-cast level of supports of floors, roofs and all
other horizontal members should not exceed span/250
316
Figure 14.5 shows the position of concentrated wheel loads on a bridge
deck. For determining the bending moments in the girders by Courbon's
theory, the reaction factors are respectively
1.80 W, 1.33 Wand 0.87 W
317. A reinforced concrete slab is 75 mm thick. The maximum size of reinforcement bar that can be used is 8 mm diameter
318. In the design of two-way slab restrained at all edges, torsional reinforcement required is Nil
319. At the time of initial tensioning, the maximum tensile stress in tendon
immediately behind the anchorage shall not exceed. 80% of the ultimate tensile strength of the wire or bar or strand
320. The cable for a prestressed concrete simply supported beam subjected to uniformly distributed load over the entire span should ideally be parabolic with zero eccentricity at the ends and maximum eccentricity at the centre of the span