In a theoretical bean-column analysis it is necessary to know the value of the effective modulus of elasticity in order to compute the critical buckling load of the member in compression. The composite specimens of this study had a slenderness ratio, 1/k « 62.7 and were not in the Euler range of buckling. The application of the tangent modulus or double modulus for analysis in the inelastic buckling range was anticipated. The writer*s approach to the problem was to ascertain the modulus of elasticity of concrete mortar and steel by compression and tension tests on cylinders and coupons. With this information it was his intention to calculate an effective modulus of elasticity of the composite specimen. Since the mortar was restrained by a steel shell it was further intended to determine the effective compression strength of the mortar annuli. All test data contained in this study are within the elastic range of the materials. Deflection readings were taken, but have not been included in this study.