A simply supported beam has a span of R/60 m and has a symmetrical l-shaped cross-section. Following data is available for the beam: fc' = 40 MPa fci' = 30 MPa Class U-member Md + MI = 0.7 R kNm e=R/3 mm St = Sp = 50 R x 10^3 mm3 Ac = 250 R mm2 | = 2500 R x 10^4 mm4 cl = c2= R/2 mm Pi = 1.7 R kN Effectiveness Ratio = 0.85 Calculate concrete stresses at transfer stage and at service load stage for the mid-span as well as for the simply supported ends. Check these values against the ACI limits. (R = 91*4+600= 964)