Concrete Technology (241-260)

241. The purpose of lateral ties in short RC columns is to

avoid buckling of longitudinal bars.

---

242. In a doubly reinforced rectangular beam, the allowable stress in compression steel is less than the permissible stress in tension in steel

---

243. The side face reinforcement, if required, in a T-beam will be

0.1 % of the web area

---

244. Consider the following statements regarding the working stress design of

under reinforced RC sections

1. The stress in steel in tension will reach its maximum permissible value

first.

2. The moment of resistance will be less than that of the balanced section.

---

245. Which one of the following sections of equal cross-sectional area can resist the torsional moment of RCC beam section more efficiently when working stress

design is being adopted? A box section

---

246. Loss of stress with time at constant strain in steel is called relaxation

---

247. Deep beams are designed for bending moment only

---

248. If 'P' is the prestressing force applied at a maximum eccentricity 'g' at mid-span, (Fig. 14.1), to balance the concentrated load "W", the balancing load will be

4.0 Pg/L

---

249. In a check for development length (L𝒹), L𝒹 shall not exceed M/V + L₀ where M, is moment of resistance of the section after bar curtailment, V is maximum shear in the region of M₁ and L₀ at discontinuous end is equal to 12 Φ (Φ is diameter of bars) or effective depth 'd' whichever is greater

---

250. In the limit state design of concrete structures the strain distribution is

assumed to be. Linear

---

251. Consider the following factors:

i). depth of cable from extreme compression fibre

Those which affect the ultimate moment capacity of a prestressed concrete beam

would include

---

252. Mᵤₗₜ of a singly reinforced balanced RC rectangular beam section is

---

253. Limit state of serviceability of prestressed concrete sections should satisfy

Cracking, deflection and maximum compression

---

254. At limit state of collapse in shear, in case of web shear cracks, it is assumed that the concrete cracks when the maximum principal tensile stress exceeds a value of f₁ equal to 0.24√fck

---

255. The loads to be taken corresponding to limit states of strength, deflection and

crack width are respectively ultimate load, working load and working load

---

256. A reinforced concrete beam is designed for the limit states of collapse in flexure and shear. Which of the following, limit states of serviceability have to be

checked ?

1. deflection

2. cracking

---

257.

Doubly reinforced section - Reduction in sectional depth Limit state design - Ultimate moment capacity Minimum cover - Durability Span depth ratio - Serviceability

---

258. The bending moment at the edges of a square vertical bunker due to a lateral pressure 'p' per unit area is pl²/12

---

259.

A. Continuous bridge - Used for large spans B. Causeways - To allow flood water to pass over C. Economic span - Used for deciding the number of piers D. Viaduct - Bridge to enable road to pass over a cutting

---

260. In concrete bridge design, the impact factor is the same for IRC class A and IRC class AA (wheeled) loadings when the span is large