摘要：The mechanical state of reinforcement concrete beams with cracks, which are acted by axial force and bending moment, is investigated. The considered ZI method is a compromise between high accuracy and volume of costs, when real curve diagrams are applied to describe the properties of materials and solution is rationally simplified by engineering assumptions. The paper presents the main formulas and algorithm for solving of engineering problems by using the ZI method. Three groups of beams have been calculated to represent the results. Two cross sections of cracked reinforced concrete beams have been analysed: at the crack and in the middle between cracks. Depending on increasing of the bending moment, the change of the location of the neutral line has been determined, diagrams of strains and stresses have been made. The possibility to take into account the deviations of the reinforcement strains from the plane section has been illustrated. The values of the bending curvatures of the beams have been also determined. The calculation results have been compared with the results of laboratory experiments, conclusions have been presented.
