Problem V The second floor of a liberary building is to be u

Problem V The second floor of a liberary building is to be used for reading space. Assume the following floor loads: Ceiling 10psf, flooring 20 ps, mechanical ducts 5 psf, partitions 20 psf. The floor live load is 60 psf (unreducible). The floor is 6-in sormal weight reinforced concrete slab. The beams supporting the slab are 30-f long spced at 11.-it on center. The beams are simple supported and weigh 225plf 21) The dead load for the second floor slab of the library is A. 105psf B. 75 psf C. 130 pst D. 110 pst 22) The live for the second floor slab of the library is: A. 80 psf B. 65 psf C. 85 pst D. 60 psf 23) The design load (We) for the second floor slab of the library i A. 262 psf B. 186 psf C 260 psf D. 252 psf ) What of the following statements is NOT true about development lengths of rebars andior hooked rebars A. If the distance from a point where a rebar stress equals fy to the end of the har is less than the development length, the bar will pull out of the concrete B. The development lengths are different in compression and tension C. The development length of a rebar is independent of the size of the rebar D. Hooks are used to provide additional anchorage when there is insufficient straigh length available to develop a bar

Solution

21)ceiling load=10 PSF

Flooring load=20 PSF

Mechanical ducts load=5 PSF

Self weight of slab=(6/12)*150=75 PSF

Total dead load on slab=10+20+5+75=110 PSF

Correct option is D

22)live load=60+20=80 PSF

23) design load=(1.2*110)+(1.6*80) =260 PSF

Correct option is C