Typological classification of defects of making the concrete core of tube confined concrete constructions

Goal. To make the classification of technological defects formation process of the concrete core on the basis of typological comparative analysis. According to the results of the latest research papers and publications, which describe the researches of defects and damages of building constructions, which lead to the reduction of their carrying capacity and reliability, similar researches on the tube-confined concrete in Ukraine are almost absent. Methods. Methods of experimental studies of the impact of existing defects and damages on the strength and nature of the stress-strain state of the tube confined concrete elements are studied. The research of samples was held at the laboratory with the help of two types of samples. One of them is tube confined concrete elements with the defects of concreting, where concrete samples filling were carried out according to various schemes. The characteristics of the cylinder concrete samples without metal shell for reducing the impact of the tube shell were also examined for more detailed study of this subject. Results. The analysis of defects research of concreting the cube confined concrete elements and sample-cylinders, which showed that the presence of even a small concrete strength variability or unsatisfactory concrete work can significantly reduce the carrying capacity of the construction to 30% was held. Sample-cylinders with the strength reinforcement 2/4l and other samples of this type, which have lower meaning of strength from 5 to 9 % have shown positive results. Concrete defects classification and the research of possible causes of their occurrence were made. Scientific novelty. Analyzing the technology of concreting there is the opportunity to estimate the defects of concreting the tube confined concrete elements and the strength of the samples in height and their impact on the carrying capacity. The results of the experimental studiescan be the basis of theoretical ground of defect-free technology of concreting core, energy efficient manufacturing technology of making reinforced-concrete constructions. They will also expand theoretical understanding of the impact of defects on the reliability of concrete core structures of this type. Practical significance. The results of the research can be the basis for preventing concrete defects and developing the main principles of standardization of technical conditions of the concerned type of the constructive elements.