Optimal control of concrete mixtures compacting by vibration method and its features

Formulation of the problem. The first information about the practical application of vibration during compacting concrete mixtures dates back to 1890. Pneumatic and ratchet vibrating devices of various types were used. After this, until 1915, scientific work and new information on the practical application of vibrocompaction of concrete mixtures are not known. In 1915, studies of vibrated concrete and hand-laid concrete as well as comparative assessment of their properties are started. The publications are appeared in various scientific and technical editions [1]. In works [2, 3], a detailed analysis of various methods of vibrocompaction of concrete mixtures, which have been used or are currently used in production, is carried out. Basically, the compaction of concrete mixtures by the vibration method is carried out with the adopted constant parameters characterizing the effectiveness of vibration effects. Such parameters for pure oscillations are the amplitude of the displacement A, the frequency f, and their derivatives [4]. Each of the listed parameters can in a certain degree characterize the vibration impact on the concrete mixture. Purpose of the article – implementation of theoretical and experimental investigations in accordance with the optimal control of concrete mixtures compaction during the production of concrete and reinforced concrete products and structures. Conclusions. The optimal control of concrete mixtures vibrocompaction process (in rapidity) has been developed and theoretically justified with using the maximum principle of academician L. S. Pontryagin, which allows effectively compacting mixtures with minimal time. On the basis of this, a new method of concrete mixtures compaction by the vibration method is offered, which can significantly improve the physical and mechanical properties of concrete. Experimental studies have confirmed the conclusions obtained during theoretical researchers to improve the concrete mixtures compaction. A comparative assessment of different methods and modes of compaction showed that the best results were obtained by applying optimal control of molding, i.e. when using the mode with multiple vibration effects. In this case, the increase in the concrete strength was 25 ... 30% in comparison with the performance of concrete compacted in the traditional way.