User talk:Mahsrt

Steps involved in design of Slab:

Find the depth of Neutral axis(Xu/d): given by:(Xu/d)=(0.87*fy/0.37*fck)*(Ast/*b*d).(given by IS:456); Where (Ast/b*d)is Reinforcement ratio(p')=(Area of steel/Area of                                                         slab). where, (Area of slab=1000*d) But, p'is the limiting value, which is=(k^2/(1-k)*2*m); where k=factor for neutral axis depth=700/(1100*0.87*fy); m=modular ratio=180/(3*Ccbc); where Ccbc=permissible comp. stress in compression, (for particular Grade:M15,M20...) Substitute for p'& find (Xu/d) the limiting value of which is (Xumax/d); (for slab since a critical or balanced section, k=Xumax/d) By which the limiting values we get are: for fy=250 it is 0.53; for fy=415 it is 0.48; since, (Xu/d)=(Xumax/d), substitute for (Xumax/d) value & get the value of "d"(for formula refering IS:456) which requires Mulim,which is taken to be Max.BM            (ex.where Max.BM=w*l^2/8,for SS span ; similarly for Cont & cantilever spans the values get from BMD);w=(Dead Load+Live Load),taking "D" the overall depth of slab for finding Dead Load. Note:for overall Depth "D" value (ex:D=Span/M.F*20,for Simply Supported(SS) span.(Similarly refer IS:456, for span/D,for Cantilever& continueous spans);          (Value,M.F=Plot of tensile stress against p')(Refering IS:456)

Mahsrt (talk) 14:45, 24 July 2009 (UTC)