METHOD OF DETERMINATION OF LONG-DURATION STRENGTH OF CONCRETE Russian patent published in 1997 - IPC

FIELD: analysis of strength of concrete. SUBSTANCE: prismatic sample is loaded to destruction with compressing axial load to value 0.75-0.85 N_max, where 2 N_max is calculated value of maximal load which sample can endure. Loading is conducted with decreasing rate and values of stresses in sample are determined simultaneously. Values of stresses and deformations are used to plot diagram, to find area of figure limited by it and to plot Prandtl diagram limiting area equal to that of diagram mentioned above. Point of crossing of diagrams and stress corresponding to this point which is assumed as parameter used to evaluate strength of concrete are determined. EFFECT: enhanced authenticity of method. 1 dwg , 1 tbl