253. For a rectangular simply supported beam for 4.5 m effective span, based on the code restriction, the depth is :

A. 180 mm

B. 225 mm

C. 300 mm

D. none of these

254. In doubly reinforced beam, tension reinforcement is designed for a stress of 0.87 aw and in compression reinforcement the stress is taken ;

A. equal to that of tension reinforcement

B. greater than the tension reinforcement

C.(c) lower than the tension reinforcement

D. double the tension reinforcement

255. The design of a doubly reinforcement beam section involves the determination of :

A. breadth of no section

B. depth of the section

C. area of tension reinforcement

D. none of these

256. The strain at the level of compression reinforcement is doubly reinforced beam is, where d' is the effective cover in compression reinforcement and Xm is the maximum depth of the neutral axis.:

A. 0.0035 (1 ? Xm d' )

B.(c) 0.087 (1 ? Xm d' )

C.(b) 0.0035 (1 + Xm d' )

D. 0.087 (1. + Xm d' )

257. In doubly reinforced beams, the percentage of the maximum compression reinforcement of the gross cross-sectional area of beam should not exceed:ack At where ay and act, are the characteristic strength of steel and concrete respectively and At is the area of tension steel

A.2%

B.3%

C.4%

D.5%

258. The slab forming the top part of flanged the beam mid span in subject to compression over a length: a

A. greater than the width of the rib

B. equal to the width of the rib

C. less than the width of the rib

D. equal to the perimeter of effective rectangular of the section

259. At continuous supports, the lower portion of

A. the slab is in tension

B. the slab is in compression

C. the slab experiences neither the tension nor compression

D. none of these

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