Buckling of Reinforced Concrete Plates

Four prediction equations are developed based on the assumptions that the composite material will behave either orthotropically or isotropically when buckling occurs and that in either case, the tangent modulus theory or the double modulus theory would prevail. The results of these analyses are applied to 24 reinforced concrete plates which were tested in uniaxial compression. The buckling loads obtained for these plates are compared with those predicted by the various formulas. The maximum difference between predictions obtained from these formulas is about 25%. It is concluded that the assumption of isotropic behavior along with the tangent modulus buckling theory yields essentially conservative, yet fairly accurate results. Formulas based on this case and incorporating certain simplifications are developed and proposed for the analysis and design of these plates.