ANALYSIS AND DEFLECTIONS OF REINFORCED-CONCRETE FLAT SLABS

The results of a test on a full-scale 5 m continuous slab are used to study the methods of analysis and calculation of deflection of reinfor ced concrete flat slabs. The most commonly used methods for the analys is of flat slabs, namely the equivalent frame method, the prismatic me mber method, the direct design method, and the finite element method, are critically compared using the results of the slab tested. Based on the comparison with the unbalanced column moments in the test, improv ements for the prismatic member method are suggested. For the deflecti on calculations of cracked reinforced concrete flexural members, three methods are investigated: the effective moment of inertia approach, t he mean curvature approach, and the bilinear method given in the CEB m anual for deflections. To calculate the deflections of flat slabs as c olumn and field strip deflections, new coefficients for distributing t he bending moments between the column and middle strips are proposed.