Iakov Iskhakov – författare

One of the main goals of a good and effective structural design is to decrease, as far as possible, the self-weight of structures, because they must carry the service load. This is especially important for reinforced concrete (RC) structures, as the self-weight of the material is substantial. For RC structures it is furthermore important that the whole structure or most of the structural elements are under compression with small eccentricities. Continuous spatial concrete structures satisfy the above-mentioned requirements. It is shown in this book that a span of a spatial structure is practically independent of its thickness and is a function of its geometry. It is also important to define which structure can be called a spatial one. Such a definition is given in the book and based on this definition, five types of spatial concrete structures were selected: translation shells with positive Gaussian curvature, long convex cylindrical shells, hyperbolic paraboloid shells, domes, and long folders. To demonstrate the complex research, results of experimental, analytical, and numerical evaluation of a real RC dome are presented and discussed. The book is suitable for structural engineers, students, researchers and faculty members at universities.

The theoretical stress-strain model for compressed concrete (Iskhakov and Ribakov, 2018), is based on the structural phenomenon and requires no empirical coefficients. It includes such main parameters of concrete behavior as stresses and strains at the border between the elastic and non-elastic behavior, ultimate elastic strains and stresses and strains at the end of the post-peak region. Particular attention was focused on the descending branch of the stress-strain diagram and on concrete elastic and plastic potentials that are important for dynamic response of concrete element section and for concrete creep.The book presents experimental and numerical results confirming this model. It deals with experimental verification of theoretical models of cracking and failure scheme for cylindrical specimens. The importance of using transverse deformations for analysis of initiation and development of inelastic deformations under high loading rates is verified. The experimental and numerical results are in good agreement with the theoretical ones, which significantly reduces the number of empirical coefficients in compressed concrete elements design.