SU845097A1 - Method of monitoring compactness of concrete mixture at vibroforming - Google Patents

Description

I. the invention refers to (pos (bam congrol of technological processes of building production).

A known method of controlling the quality of a concrete cMecii V / v from that measured by the power consumed by the vibrator and comparing it with a given one, upon reaching which, the process of vibroforming f i j is stopped.

However, this method does not provide sufficient control accuracy.

There is also known a method for controlling the compaction of a concrete mix during vibroforming, including the H3Mepeiuie signal from the vibration sensors and fixing the stabilization moment Kiiii of the properties of the laid concrete mix 2. With this method, the end of the process is determined by the phase difference.

However, this method does not provide sufficient () accurate control of the vibrating compacting process during the molding of particularly hard concrete mixtures due to incomplete reflection of the physical picture of the phenomena occurring in the treated medium, as a result of which it is possible to conditionally take the moment of stabilization of measurements for optimal compaction time

The purpose of the invention is to increase the accuracy and reliability of the controls.

This is achieved by the method of controlling the compaction of a concrete mixture during vibroforming, which includes measuring the signals of the vibration sensors and fixing the moment of stabilization of the properties of the laid concrete concrete, then calculate the characteristics of the hysteresis loop using a pressure sensor and calculate the angle the slope and area of the hysteresis loop, and the fixing of the moment of stabilization of the properties of the compacted concrete mix is carried out to achieve the maximum angle of inclination and the minimum square hysteresis loop.

FIG. Figure 1 shows schematically an apparatus for carrying out the proposed method; in fig. 2 shows graphs of the dynamic modulus of elasticity and energy dissipation in a layer of concrete mix with time.

The method for controlling the compaction of a concrete mix is carried out as follows.

Claims (2)

The concrete mixture is placed in the form 1 (see Fig. 1). In a layer 6-8cm thick, a massdose 2 is installed, and displacement sensors 3 are placed along its boundaries. The form is fixed on the vibrating plate 4, and a submersible device 5 is placed on the surface of the concrete mix if necessary. The outputs of the sensors are connected through an amplifier 6 to the oscilloscope 8, and through the converter 9 - to the integrator 10. To perform the vibro-forming, they include the vibrator AND and follow the indicators of the logometer 7, which records the dynamic modulus of elasticity, the integrator 10, which measures the amount of energy dissipated and behind the oscilloscope screen, where the overall change in the hysteresis loop is reflected. At the beginning of the vibroforming of a concrete mix, the dissipated energy begins to rise sharply to its maximum value. (see Fig. 2, curve 1), and then begins to decrease with time and stabilizes (point A), the elastic modulus (E) increases more smoothly and reaches the value of .Kc. (see Fig. 2, curve II). Experimental data are given for the following source data; concrete mix of 1: 1.2: 3.3, B 0.37 F 40s according to the technical viscometer, vibration parameters: f 50 Hz, A 0.5 mm. Both E and AW are stabilized at the same time (in Fig. 2 at point A). At this point, vibroforming is stopped, because the compaction process is completed, and a further increase in the vibrating time does not increase the density of the concrete mix, and sometimes can lead to its decompression, which can be observed by reducing the angle of inclination and increasing the area of the hysteresis loop. mixtures during vibroforming, including measurement of signals from vibration sensors and fixing the moment of stabilization of the properties of the laid concrete mix, characterized in that, in order to improve the accuracy In addition to measuring the characteristics of the hysteresis loop with the help of a mass-dose, and based on the measured signals of the vibration sensors and the mass-sensors, the slope and the area of the hysteresis loop are calculated, and the moment of stabilization of the properties of the compacted concrete mix is determined hysteresis loops. Sources of information taken into account in the examination 1. USSR author's certificate number 490009, cl. G 01 N 33/38, 1970. 2. USSR author's certificate number 591764, cl. G 01 N 33/38, 1975 (prototype). four but. / 3 // ./ fJpoffo / fJKi / 777e / 7M (C777 & yn / ffm ef / i / s / fl / 1 / Schg / H iPveJ