Analysis of the spectrum distribution of oscillation amplitudes of the concrete mix at shock vibration molding

Abstract

Abstract. In the production of concrete structures widespread shaking tables of various designs. The effectiveness of vibroforming concrete items largely depends on the choice of rational modes of vibroeffect to the compacting mixture. The article discusses the propagation of a wave packet in the concrete mixture under shock and vibration molding. Studies have shown that the spectrum of a wave packet contains a large number of harmonics. The main parameter influencing the amplitude-frequency spectrum is the stiffness of elastic gaskets between mold and forming machine vibrating table. By varying the stiffness of the elastic gaskets can widely change the spectrum of the oscillations propagating in the concrete mix. Thus, it is possible to adjust the intensity of the process of vibroforming.The theory and practice of vibratory compaction of concrete mixtures are still relevant in the production of concrete items and structures [1][2][3]. The main tasks in easel forming concrete items are the choice of effective modes of vibration effects and rational parameters of the shaking tables.Unfortunately, when using standard molding conditions of existing construction vibrating equipment does not meet modern requirements. This is due to their large resource consumption over the low quality of manufactured concrete items, low operational reliability, as well as the excess of admissible norms of noise and vibration [4,5].To compact firm concrete mix B. V. Gusev [6] developed the theoretical foundations of shock and vibration technology. Staff members of his school were created and installed equipment for implementing low-frequency modes forming concrete items [1,7]. In other works [8,9], as effective modes of compaction of firm mixes it is proposed to use the socalled asymmetrical shock-free oscillations. The advantage of applying these oscillations is the absence of oscillating vibrotable with the balancing frame.In articles [10, 11] described optimization of parameters of shock and vibration shaking tables for efficient modes of forming concrete items of firm concrete.It is interest to consider the process of propagation of a wave packet in concrete mix under shock and vibration effects on the mold and explore a range of pulses, which propagate in the mixture.

Choice of parameters of oscillatory actions in the molding of reinforced concrete products

“…The distribution of the obtained solutions to real concrete mixtures, which are multiphase multicomponent media, will be more correct if we take into account the degree of influence of the shape and spectrum of the shock-vibration impulse on the behavior of the compacted medium [17].…”

Coexisting Regimes in Hysteresis Zone in Platform-Vibrator with Shock

“…The gasket stiffness is one of the most important parameters of this system. It is determined by the shape, sizes and elasticity modulus of the gasket material [5,6]. In [2], the influence of the gasket stiffness on the system dynamics was experimentally investigated in a particular case of a shock-vibrational machine.…”