Method of preparing concrete mixture

FIELD: chemistry.

SUBSTANCE: invention relates to construction and specifically to the technology of preparing concrete mixtures and articles therefrom. The method of preparing a concrete mixture involves mixing a portion of a calculated dose of grouting fluid with cement in a mixer-activator; feeding the remaining portion of the calculated dose of grouting fluid into a concrete mixer with an aggregate; subsequently feeding the suspension obtained in the mixer-activator into the concrete mixer and final mixing of the obtained mixture; the grouting fluid used is water which is poured into the mixer-activator in a volume of (40-70)% of the calculated formation dose of the grouting fluid which is activated when pouring into the mixer-activator by passing it at a rate of (1-2) m/s through a transverse magnetic field whose strength lies in the range of (500-2000) Oe; after pouring into the mixer-activator, said fluid is subjected to additional secondary activation by cavitation disintegration through exposure to ultrasound with frequency higher than the cavitation threshold in the low frequency range from 20 kHz to 100 kHz, and intensity of said ultrasound is in the range of stable cavitation from 1.5 W/cm2 to 2.5 W/cm2, wherein during cavitation disintegration of the grouting fluid, cement is added and stirred; the grouting fluid is poured into the mixer-activator while simultaneously pouring the remaining calculated formation dose of the grouting fluid into the concrete mixer with an aggregate, which is in form of water which, when pouring into the concrete mixer with an aggregate, is magnetised by also passing it at a rate of (1-2) m/s through a transverse magnetic field whose strength is in the range of (500-2000) Oe; after mixing the suspension - cement paste in the mixer-activator for 1-1.5 minutes, it is then discharged into the concrete mixer and the obtained mixture is finally stirred for 1.5-2 minutes.

EFFECT: faster hardening of the mixture and high strength of concrete.

1 dwg

 

The invention relates to the field of construction, namely, the technology of preparation of concrete mixtures and products from them.

Known activation method of the cement test by exposure to alternating DC in electroactuator [1].

The disadvantage of this method is its low productivity, and the need to use electrical equipment for straightening industrial alternating current and its impact on the cement dough.

Additionally, developed the inner surface of electroactuator in contact with the concrete mixture, complicates the process of its purification from the adhered cement paste.

The closest known methods is the way of separate preparation of the concrete mixture by pre-cooking the cement test in a high-speed mixer-activator with its subsequent mixing with the aggregate in the mixer to the finished concrete mix. Mixer-activator provides mixing of cement with water at a speed of rotation (18÷24) m/s [2].

The disadvantage of the prototype method is the low speed and the degree of cement hydration, long setting time of cement and low strength concrete stone.

The technical problem to address with the inventive method of preparing a concrete mix is povyshenie speed and degree of hydration of the cement, the rate of hardening and strength of concrete.

The solution of this problem is that in the method of preparation of the concrete mixture, comprising mixing in a mixing activator portion of the calculated dose of the liquid mixing with cement, introducing the remaining portion of the calculated dose of fluid mixing in the mixer with the filler, the subsequent introduction obtained in the mixer-activator slurry in the mixer and the final mixture, the fluid mixing water use, which is pre-filled into the mixer-activator in volume (40÷70)% of rated (RX) dose of fluid mixing and in the process of filling in a mixer-activator activate it, for what passed with a speed of (1÷2) m/s through a transverse magnetic field, the intensity of which lies in the range (500÷2000) E. Then, after pouring said liquid into the mixer-activator, it is subjected to additional secondary activation by cavitation disintegration, which affected the ultrasound, the frequency of which is higher than the frequency of the cavitation threshold in the range of mid-frequency ultrasound of 20 kHz to 75 kHz, and the intensity of the above-mentioned ultrasound lies in the area of stable cavitation from 1.5 W/cm2up to 2.5 W/cm2. Moreover, in the process of cavitation disintegration of the liquid for the of its in her fall asleep and mix cement. At the same time with fill fluid mixing in a mixer-activator is poured into the mixer with the aggregate remaining from the settlement (RX) dose of the fluid mixing, which use water, which is in the process of pouring concrete mixer with placeholder passed with a speed of (1÷2) m/s through a transverse magnetic field, the intensity of which lies in the range (500÷2000) E. After stirring the slurry (cement paste in mixer-activator for 1-1,5 minutes it was poured into a mixer and the resulting mixture was finally stirred for 1.5-2 minutes.

The invention consists in the following. The speed and degree of cement hydration are strongly influenced by the properties of the fluid mixing. However, in common, even purified using filters water may be present in organic substances such as sugars and phenols, which slow down the normal flow of the process of hydration of the cement and thereby reduce the strength of the concrete. With a large content of phenols and sugars concrete setting can generally be pulled indefinitely. Therefore, water mixing, the amount of sugar or phenols should be no more than 10 mg/l each.

A particular danger is the presence of water soluble salts, sulfate ions and chloride ions. They can be the cause uncontrollable changes in terms of setting and hardening rate of concrete. But most importantly, there is a risk of corrosion of cement and steel reinforcement in concrete. With a large number of sulfate ions in the concrete begins sulfate corrosion that destroys the cement stone and concrete construction in General. Chlorine ions cause corrosion not only in the cement stone, but in the steel reinforcement.

Soluble salts (great content) after hardening of the concrete crystallize in the pores of cement paste and form on the surface salt deposits, the so - called efflorescence, spoiling the appearance of the buildings.

Therefore, for mixing the concrete mix and watering curing of concrete should be very careful to apply drinking water, as well as river, lake or water from artificial reservoirs, as using any of the following types of water does not guarantee that it is completely absent mentioned impurities. Therefore, in order to secure the elimination of the above disadvantages it is necessary to apply some additional technological measures, in particular, the magnetised water.

The magnetised water allows you to eliminate some of the factors impeding the effective hydration of cements and deteriorating quality properties of concrete, for example, partly to reduce the salt crystals rigidity in comparison with the size of the salt crystals gestco and in the source water.

Magnetic treatment of water involves passing it through a transverse magnetic field. On the still water of the magnetic field are much weaker, because the processed liquid always has some conductivity, moving in magnetic fields excited by a small electric current. Therefore, more accurate to assume that is not magnetic, and electromagnetic water treatment. In the General case, the change of water properties after magnetic treatment increases with the concentration of impurities in the water and change their nature [3]. This is important from the point of view of the directional control properties of water, including increasing its active (reactive) properties and stabilization of this effect. The impact on water of a magnetic field affects the processes of dissolution, wetting, boiling, adsorption, coagulation and other active properties of water, which ultimately affects chemical reactions in many technological processes. These phenomena are entirely the reactions of hydration and hydrolysis of binding agents. Therefore, the magnetised water and use it as a fluid mixing increases the hydration of the cement.

The range of speed of water movement in a transverse magnetic field and the range of tension transverse magnetic field due to the following circumstances.

In the process of magnetic treatment of water is not observed any changes in the values of pH and redox potential, and only the fragmentation and reduction in size of the crystals of hardness salts in the water. Experiments have shown that the optimal value of the speeds of the treated water in a transverse magnetic field is in the range (1÷2) m/s, and the optimal value of intensity of the transverse magnetic field lies in the range (500÷2000) E. Research conducted using a microscope showed that when the speed of movement of water less than 1 m/s and intensity of the transverse magnetic field less 500 e, a reduction in the effectiveness of magnetic water treatment, resulting in a slight (1.5÷2 times) reduction of salt crystals stiffness compared to the size of the crystals of hardness salts in the source water.

When the running speed of the treated water in a transverse magnetic field in the range (1÷2) m/s and the value of intensity of the transverse magnetic lying in the range 500÷2000) uh, is more significant (8÷12 times) reduction of salt crystals stiffness compared to the size of the crystals of hardness salts in the source water. Further increase in the rate of movement of water is 2 m/s and increasing the tension transverse MAGN the private field for the 2000 e does not lead to a substantial decrease in the crystals of hardness salts. Therefore, the water magnetization that occurs in the process of filling in a mixer-activator when the velocity of its motion (1÷2) m/S. However, one activating fluid mixing only by magnetised water, can only partly to increase the hydration of the cement and to improve technological and operational properties of concrete and concrete structures.

The effect of cement hydration and improvement of technological and operational properties of concrete and concrete structures increases significantly when additional (secondary) activation fluid mixing by exposure to ultrasound. By their physical nature ultrasound is an elastic wave, and in this he is no different from the sound.

The frequency boundary between sound and ultrasonic waves conditional, it is determined by the subjective properties of the human ear and is the averaged upper limit of the audible sound. It is considered that the ultrasonic range includes frequencies in the range from 20 kHz to 1GHz. Frequency in the range from 16 kHz to 20 kHz, refer to audible sound.

Frequencies below 16 kHz are infrasound, and frequencies above 1 GHz, called supersonic.

The frequency range of the ultrasound can be divided into three sub-regions:

ultrasound low frequency (2×104 -105Hz) - ULF;

the mid-frequency ultrasound (105-107Hz) - USC;

ultrasound-high frequency (107-109Hz) - USVC.

In liquid medium under the action of ultrasound occurs and proceeds specific physical process of ultrasonic cavitation, providing maximum energy impact on the liquid and solid, in particular on the cement particles in liquids.

Cavitation is the formation in fluid pulsating bubbles (cavities, voids)filled with steam, gas or their mixture. In an ultrasonic wave during the half-periods of depression occur cavitation bubbles, which abruptly shut after moving to an area of high pressure, giving rise to strong hydrodynamic disturbances in the fluid, intense radiation of acoustic waves. Thus, in the liquid destruction occurs on solid surfaces bordering the cavitating fluid.

Cavitation is the rapid formation and collapse of millions of tiny bubbles (or cavities) in a liquid. Cavitation is produced by the alternating waves of high and low pressure created by high-frequency sound (ultrasound). These bubbles grow in size from microscopic (in the phase of low pressure) to such an extent (in the high pressure phase), in which they compress the Xia and torn.

Ultrasonic cavitation is the main initiator of physico-chemical processes occurring in the liquid under the action of ultrasound. It is realized through the transformation of the low energy density of the ultrasound in high energy density near and inside the gas bubble.

Cavitation phenomena in a particular environment occur only when exceeding the ultrasound cavitation threshold.

The cavitation threshold is called the intensity of the ultrasound, below which are not observed cavitation. The cavitation threshold depends on the parameters characterizing both the ultrasound and the liquid.

For water and aqueous solutions cavitation thresholds increase with increasing frequency ultrasound and reducing the time of exposure.

In water at frequencies above 20 kHz the threshold unstable cavitation is in the range from 0.3 W/cm2up to 1 W/cm2.

Further increase in intensity of 1.5 W/cm2leads to the violation of the linearity of the oscillations of the walls of the bubbles. Stable cavitation stage begins. The range of intensities of stable cavitation lies in the area of 1.5 W/cm2up to 2.5 W/cm2. The bubble itself becomes a source of ultrasonic vibrations. On its surface waves occur, microcurrents, electrical discharges.

The increased intensity ultrasound for the value of 2.5 W/cm2bring the back to the stage of unstable cavitation. It is characterized by the formation of growing gas bubbles that are in the phase of compression instantly reduced in volume and klapivad, i.e. comes the collapse.

Best hydration of cement particles occurs in the range of stable cavitation occurring at low frequencies. Therefore, to activate the fluid mixing concrete mixes best ultrasound low frequency. The choice of this frequency range due to the following factors.

First, the frequency of 20 kHz is taken as the lower boundary of occurrence of ultrasonic vibrations. At frequencies below 20 kHz is the area of the audible sound and the process of cavitation in this region are not observed.

Secondly, in the low frequency range lying between 20 kHz to 100 kHz, the range of intensities of ultrasound, in which there is a stable cavitation, as it was mentioned above, lies in the field of 1.5 W/cm2up to 2.5 W/cm2.

The frequency range above 100 kHz, relates to the field of mid-frequency ultrasound. In this frequency region can be a number of events that will adversely affect the properties of concrete. In particular, in this frequency range can occur in structural changes of the cement particles, which can lead to lower clinker properties of cements and the strength of the concrete stone. In this frequency range particularly when the th intensity ultrasound can produce the effect spouting jets activated liquid that can also cause adverse effects in the preparation of concrete mixes. In addition, to ensure stable cavitation in the midrange, requires a more powerful irradiator than to create a named region in the low frequency range. This is due to the fact that the cavitation threshold increases with the frequency of the ultrasound. The necessity of a more powerful emitters in the midrange compared to the power of the emitters in the region of low frequencies, results in a complicated and expensive design activator cement.

The cavitation phenomena in the field lead to a number of useful phenomena in the process of mixing cement.

First, the cavitation process leads to active cleaning the surface of the particles of cement from possible organic films, preventing hydration of the cement.

Secondly, the activation fluid mixing by cavitation disintegration is carried out after filling in a mixer-activator by exposure to ultrasound, the frequency of which lies above the frequency threshold, cavitation, and cavitation process of disintegration of liquid mixing in her fall asleep and mix cement. The particles of the medium (cement and water) oscillate with small amplitude (fraction of a micrometer) and huge accelerations of the order of 105×g, where g=98 m/s 2- acceleration of free fall.

Thirdly, ultrasonic vibrations provide an ultrafine dispersion of cement particles in the fluid mixing (not implemented in other ways), increasing the interfacial surface of the reacting elements. This is one of the mechanisms of intensification processes in liquid media.

Fourth, arising under the influence of fluctuations in fluid cavitation and the accompanying powerful mikropotokami, sound pressure and sound the wind impinges on the boundary layer of the particles of cement and "wash" it. This eliminates the resistance of the transfer of the reacting substances and intensified the process of hydration of cement particles.

Fifthly, to increased hydration of the cement results in a local temperature rise in cement paste.

Explanation of how a temperature increase in the particles of cement, is simple enough: penetrating the cement particles, ultrasonic waves lose energy, passing it the system through which they pass. The transferred energy is converted into heat and the temperature rises considerably, especially at the boundary of liquid and solid phases, with different degree of acoustic impedance.

For different fluid pressures, which yields the cavitation is in the range of from 1.0 to 3.9 and the m For water, this pressure is 1 ATM.

Thus, in the fluid mixing occur such physico-chemical phenomenon of acoustic cavitation, intensive mixing, the alternating motion of the particles of cement, the intensification of mass transfer processes.

The impact of ULTRASOUND with a frequency of 20-100 kHz is characterized by the separation of molecules and ions with different mass, the waveform distortion, the appearance of an alternating electric field, capillary-acoustic and thermal effects, the activation of diffusion.

Under the action of ultrasonic cavitation accelerates the reaction of mechanical origin that took place in a busy environment before exposure to ultrasound, in particular the processes of cement hydration. The main type of proceeding here chemical processes are redox reactions.

All chemical reactions begin with a certain threshold, coinciding with the beginning of cavitation. Initially, the product yield of the reaction is proportional to the power density and the time of speaking. After exceeding a certain intensity speed zvukokhimicheskie reaction decreases sharply. This is because at high intensity ultrasound increases the maximum size of the bubbles and they do not have time to slam half-cycle of the wave.

At low frequencies cavitation nachinaetsya smaller intensities and, accordingly, the reactions take place at lower intensities.

Ultrasound accelerates autoxidation solids, especially the processes of hydrolysis, cleavage, oxidation. When exposed to the dissolution of ultrasound in a liquid medium arise alternating acoustic pressure, facilitating the penetration of the liquid into the cracks and capillaries of the cement particles, and fast currents: the sound of the wind, cavitation. The intensification of the process of hydrolysis of cement, as well as the diffusion coefficient depend on the values of the amplitude and frequency of forced oscillations of the liquid. When exposed to the environment of ultrasound decreases the dynamic viscosity of polar liquids; microcracks and pores present in the particles of cement, branch, increase their size and depth. Considering the hydrodynamics of the environment in a single capillary (crack), it is possible to distinguish three zones: turbulent fluid flow, viscous sublayer and the diffusion sublayer. At the edge of open microcracks during intensive movement of fluid occurs turbulization of mikropotokami, and then stall vortices. Here the process of dissolution of the solid phase is limited by the coefficient of turbulent diffusion. Coming from the first to the second zone of turbulent pulsations transfer the main mass of the dissolved substance. In the third zone mass transfer due to the Yong chaotic molecular movement. Longitudinal and transverse cracks are an important factor in the process of hydrolysis. When the ultrasonic appearance of alternating pressure (±5×105PA) in the liquid in the crack created oscillatory tangential displacement of microvolumes of liquid mixing along the walls, moving in a unidirectional movement of the solution. Molecular diffusion is practically replaced fast enough by convective mass transfer.

Thus, with the use of ultrasound as a means of intensification of the process of cement hydration are essential to micropulsation fluid mixing, especially if the wavelength is equal to or smaller than the size of solid particles (cement) or linear dimensions of microcracks, pores, capillaries.

The combination of magnetic water treatment with the processing of its ultrasonic disintegration is not a simple addition to these factors, and complement and strengthen one another. Joint magnetic activation of water and additional water activation ultrasound gives a cumulative effect.

Any concrete mix is prepared in accordance with the selected recipe. Each recipe provides, how much you need to mix cement, liquid mixing and fillers in order to obtain concrete with the desired properties. These recipes su is basically a lot of [4]. Therefore, for each specific recipe and the required volume of concrete mix is calculated required intake of cement, liquid dose mixing and dose placeholder for any single batch. Total calculated dose of liquid mixing in a single batch, which is required for the preparation of concrete mix in some recipe, taken as 100%. In the claimed method in a turbulent mixer-activator filled (40÷70)% of the volume of the sealing liquid from its calculated dose. The rest (30÷60) of the liquid mixture is poured into a mixer with a placeholder. The division estimated (RX) dose of the liquid into two parts, one of which is poured into the mixer-activator is mixed with particles of cement, and the second part is poured into the mixer where it is mixed with a filler, due to the following factors.

First, this separation of the liquid mixing is necessary to improve the performance of the process as a simultaneous mixing liquid mixing with cement in turbulent mixing activator, and mixing the remainder of the settlement (RX) dose of fluid mixing with the aggregate in the concrete mixer.

Secondly, to make slurry (cement grout) and the mixture in the mixer with the placeholder can be used for p is increasing process efficiency, different physico-chemical properties of the fluid mixing, for example, manicina water past the secondary activation by cavitation disintegration, and manicina water is not affected by secondary activation. The volume of fluid mixing, which is poured into the turbulent mixing of the activator depends on the water-cement number In a/C, characterizing the ratio of the weight of water to weight of cement C required to prepare 1 m3concrete mix according to the given recipe prepared concrete mix. The higher water / cement ratio, the lower part of the liquid mixture is calculated from (RX) dose of the sealing liquid may be filled in a turbulent mixer-activator. At high water-cement number, for example,/C=1,28 in turbulent mixer-activator enough to fill 30% of the calculated dose of a liquid mixture that is high enough for satisfactory hydration of the cement and high quality obtain slurry (cement grout). If you fill in the turbulent mixing of the activator is less than 30% of the calculated dose of fluid mixing, this can lead to reduced hydration of the cement and reduce the quality of the concrete mix. At low water-cement number, for example, the W/C=0.3 turbulent mixing activator, you need to fill at least 70% of the calculated dose of fluid mixing, since p and a smaller amount of the sealing liquid will be difficult to provide a satisfactory hydration of the cement and obtaining high-quality slurry (cement grout).

After magnetic treatment of fluid mixing it poured in a turbulent mixer-activator and subjected to secondary activation by cavitation disintegration, in which a turbulent mixer-activator poured cement.

The resulting cement paste, stopping to affect this dough ultrasound, mix in a turbulent mixer-activator. Turbulent mixing in the mixer-activator, increased hydraulic liquid mixing with the particles of the cement caused by ultrasonic cavitation and magnetic treatment of fluid mixing is facilitated by the active removal of films that occur around the cement grains and preventing their hydration. Due to this, the active surface of the cement grains exposed on the increase, due to their fragmentation in the process of cavitation disintegration, thereby creating more favorable conditions for the development of the hydration process in the depth of the cement grains. Due to the intensive mixing in turbulent mixing activator slurry (cement paste) provides active engagement of the entire mass of the cement liquid was prepared.

The remaining portion of the liquid mixing volume (30÷60)% of the calculated dose is administered, pre-exposing her treatment in a magnetic field, fill in neposredno is but in a mixer with a placeholder. Additional cavitation disintegration of this remaining part of the liquid mixture is poured into a mixer, to conduct impractical because the basic processes of hydration of cement particles occur in the mixer-activator. After stirring the slurry (cement grout) for 1÷1.5 minutes it was poured from a turbulent mixing of the activator in the mixer, which produces its mixing with a filler to obtain a uniform consistency for 1.5-2 minutes.

The select time range mixing cement paste in the mixer-activator due to the following circumstances. When mixing time in the mixer is the activator is less than 1 minute may not be complete hydration of the cement. Increase mixing time in the mixer-activator for 1.5 minutes is impractical because it reduces productivity.

Selecting a time range for the mixing of concrete mix in the mixer due to the following circumstances. The filler with the liquid mixture is mixed in the mixer simultaneously with the mixing of the cement paste in the mixer-activator during the same time 1÷1.5 minutes. During this time not only cement the batter evenly promahivaetsya throughout the volume of the mixing activator, but also evenly promahivaetsya in betonosmesitel the filler with a liquid dissolution in the whole volume of the mixer. After draining the cement grout from the mixer-activator in the mixer for uniform mixing of the formed concrete mix requires at least 1.5 minutes. Increase mixing time during 2 minutes leads to reduced productivity.

Figure 1 shows a diagram of concrete preparation, explaining the essence of the invention.

Figure 1 introduced the following notation: 1 - motor turbulent mixing activator; 2 - the motor shaft; 3 - the case of turbulent mixing activator; 4 - stationary blades turbulent mixing activator; 5 - blades turbulent mixing activator; 6 - industrial sound processor; 7 - water tank; 8 - water dispenser in turbulent mixing activator; 9 - pole magnets; 10 - drive cement; 11 - dispenser cement; 12 - water tank; 13 - dispenser water in the mixer; 14 - pole magnets; 15 - drive placeholder; 16 - spout filler; 17 - mixer; 18 - valve for discharge of slurry (cement grout); 19 - discharge system of the concrete mix; 20, 21 - water.

Turbulent mixing activator provided with a motor 1, the transmitting torque of the blades 5 through the shaft 2. To the body of the activator 3 is attached stationary blade 4, promote turbulent mixing of the mixture. In turbulent mixing is ctivator entered the industrial sound processor 6. Turbulent mixing activator has a shutter 18 for discharging slurry (cement grout). The case of turbulent mixing activator is equipped with nozzles for water supply and delivery of cement.

Method of preparation of activated concrete mixture as follows.

From the drive water 7 through the water dispenser 8 is poured into the mixer-activator (40÷70)% of the volume from the prescription dose of fluid mixing at a speed of (1÷2) m/s of its motion through the water supply 20, which is passed through a transverse magnetic field (pole magnets 9), the tension of which lies in the range (500÷2000) E. After magnetised and fill in the mixer-activator required dose of fluid mixing include industrial sound processor 6. With an industrial sound processor 6 produce secondary activation fluid mixing by cavitation disintegration. Cavitation disintegration fluid mixing is carried out by ultrasound, the frequency of which is higher than the frequency of the cavitation threshold in the low frequency range from 20 kHz to 100 kHz, and the intensity of the above-mentioned ultrasound lies in the area of stable cavitation from 1.5 W/cm2up to 2.5 W/cm2. Simultaneous with the start of the industrial sound processor 6 from the drive cement dispenser 10 through the cement 11 is poured into the mixer-cement activator is, and without cavitation disintegration of liquid mixing, include motor turbulent mixer-activator 1, which is stirred formed by the cement paste. Simultaneously with the pouring of liquid mixing in a mixer-activator, is poured into the mixer estimated dose placeholder from the drive placeholder 15 through the spout 16, and pour remaining from the settlement (RX) dose of the fluid mixing in the mixer 17 with a placeholder.

As mentioned poured into the mixer doses of liquid mixing also use water, which is poured from the drive water 12 through the spout 13, and in the process fill in the mixer 17 with placeholder her Magnificat. To activate the water magnetization that it passed with a speed of (1÷2) m/s through a transverse magnetic field (pole magnet 14), the tension of which lies in the range (500÷2000) E. Then, after stirring the slurry (cement paste in mixer-activator for 1-1,5 minutes, open the shutter 18 for discharging slurry (cement grout) and the suspension is poured into a mixer 17. The resulting concrete mixture is finally stirred in the mixer for 1.5-2 minutes.

After preparing the concrete mix evenly mixed concrete is discharged from betonom is sites in the discharge system of the concrete mix 19.

An example of a specific playback method.

The inventive method was carried out according to the scheme depicted in figure 1.

Study of the effect of liquid mixing on the cement hydration and properties of concrete and concrete was carried out in two stages. In the first step, experiments were conducted on cement stone, it was investigated characteristics such as the setting time of cement, hydration of cement and increase the strength of cement stone. In the mix were used Portland cement.

To compare the proposed method with the method of the prototype was prepared with 3 kneading. The first batch was prepared according to the method prototype. In this mixture as a liquid mixing was used ordinary tap water.

The second difference from the first batch consisted in the fact that it is as fluid mixing was used the same tap water, but activated by a magnetic field. To activate the water in this batch it was passed with a speed of 1.5 m/s through a transverse magnetic field, the intensity of which was equal to 1500 E.

The third batch was made by the present method. In this mixture as a liquid mixing water was used, since a double activation: original by passing it with a speed of 1.5 m/s through a transverse magnetic field, the intensity of which was Ravna E. Then, after filling the required dose of this minichannel water, it is in the process of filling in a mixer-activator cement, was affected by the ultrasound frequency was 20 kHz, and the intensity of the above-mentioned ultrasound lay in the field of stable cavitation and was equal to 2 W/cm2. As cavitation cage was used industrial sound processor "Hielscher Ultrasound Technology UP" brand UIP 1000 hd [5]

All technological operations in the manufacture of these three mixtures were identical: first mix the activator was poured liquid mixing, which amount was the same in all three mixtures, and it was 50% of the prescription (current dose), then mix the activator was filled required in accordance with the prescription dose of cement. The difference in these mixes was only a preparation operation of the fluid mixing described above.

The experiments were conducted on cement stone, it was investigated characteristics such as the setting time of cement, hydration of cement and increase the strength of cement stone. In the mix were used Portland cement. Water / cement ratio in these experiments was equal to the W/C=0.3, and where In - water consumption for 1 m3concrete, kg; C - consumption of cement per 1 m of concrete, kg

The experiments showed that the setting time of the cement test, prigotovlennogo the method prototype, was 3 hours 10 minutes. The setting time of the cement dough, cooked the second batch was 2 hours and 10 minutes. The setting time of the cement test prepared by the present method, was 1 hour 5 minutes. Plastic strength cement paste prepared according to the method prototype, after 4 hours of curing was 0.15 MPa. Plastic strength cement paste, cooked the second batch was 0.35 MPa. Plastic strength cement paste prepared by the present method, after 4 hours of curing amounted to 0.78 MPa. The hydration of the cement was investigated by x-ray diffraction method to install a DRON-4. Studies have shown that cement paste prepared according to the method prototype hydration of cement amounted to 65%. In the second batch hydration of cement was 72%, whereas by the present method it was equal to 86%.

In the second series of experiments studied the selective activation of cement and aggregates. For such studies was prepared 3 batch concrete mix. The concrete composition in all three mixes was almost identical. Water / cement ratio in all three batches were equal to the W/C=0,55. Part 1 m3the concrete mix consisted of: In=200 l; p=365 kg; sand N=600 kg; gravel G=1145 kg

The first batch of concrete mixture was carried out according to the method-ol is the totype, and as a liquid was prepared as in the preparation of cement paste and in the final concrete mix was used with ordinary tap water. When cooking the first batch volume of water was divided into parts: 109,5 l 90,5 L. One part 109,5 l was used for mixing concrete test. The second part 90,5 l was poured into the mixer with a placeholder.

In the second batch as fluid mixing was used the same tap water, but activated by a magnetic field. To activate the water in this batch it was passed with a speed of 1.5 m/s through a transverse magnetic field, the intensity of which was equal to 1500 E.

The third batch was made by the present method. In this mixture as a liquid mixing water was used, since a double activation: original by passing it with a speed of 1.5 m/s through a transverse magnetic field, the intensity of which was equal to 1500 E. Then, after filling the required dose of this minichannel water on it in the process of filling in a mixer-activator cement, was affected by the ultrasound frequency was 20 kHz, and the intensity of the above-mentioned ultrasound lay in the field of stable cavitation and was equal to 2 W/cm2. As cavitation cage was used industrial sound p is ocessor "Hielscher Ultrasound Technology UP" brand UIP 1000 hd.

The procedure for preparation of cement grout in all three batches were identical. In a turbulent mixer-activator poured liquid mixing in the number 109,5 l when the engine 1 in the mixing mode. Then fell asleep in a turbulent mixer-activator cement from the drive 10 through the spout 11 in the amount of 365 kg Duration of mixing cement paste in the mixer-activator in all three mixtures was 1 minute. The duration of mixing in a mixer concrete mixture, after overflow in him cement grout was 2 minutes. Thus the total duration of the preparation of the concrete mix was 3 minutes. The mixture was discharged into a vehicle for transportation to the place of installation. To estimate the strength of concrete under normal conditions made reference samples-cubes rib 150×150×150 mm, which was tested at age 28 days of storage in the camera normal setting.

The test results strength showed that in 28 days age strength of concrete prepared by the present method in the second batch, exceeded the strength of concrete prepared according to the method prototype is 20%, and the strength of concrete stone, prepared by the present method in the third batch - by 42%.

Thus, the inventive method has the following advantages : the STV before the method of the prototype: the increased hydration of the cement by 21%; reduced 2.92 times the setting time of the cement, high 5, 2 times the plastic strength of cement paste at early stages of mixing, increased by 42% strength concrete stone at 28 days age.

Sources of information

1. USSR author's certificate No. 146228, CL VS 5/00, 1961.

2. Solomatov V. and other Intensive technology of concrete. - M.: stroiizdat, 1989, p.69-75.

3. Golikov A.N., Zaslavsky A, Stupachenko percentage POINTS the Use of magnetic water treatment plants in the Far East // Vladivostok: publishing house of the far Eastern University. 1990, str. - (Prototype)

4. B.C. Batalov. Theoretical foundations vibrotechnics of monolithic concrete: Monograph. Magnitogorsk: GMA, 1998, p.41-53.

5. Inquiry from http://www.hielscher.com.

The method of preparation of the concrete mixture, comprising mixing a portion of the calculated dose of the liquid mixing with cement in the mixer-reactor, introducing the remaining portion of the calculated dose of fluid mixing in the mixer with the filler, the subsequent introduction obtained in the mixer-activator slurry in the mixer and the final mixture, wherein as fluid mixing water use, which is pre-filled into the mixer-activator in volume (40÷70)% of rated (RX) dose of fluid mixing, which in the process is filling in a mixer-activator activate, why miss with the rate (1÷2) m/s through a transverse magnetic field, the intensity of which lies in the range (500÷2000) uh, then, after filling in a mixer-reactor, the said liquid is subjected to additional secondary activation by cavitation disintegration, which affected the ultrasound, the frequency of which is higher than the frequency of the cavitation threshold in the low frequency range from 20 kHz to 100 kHz, and the intensity of the above-mentioned ultrasound lies in the area of stable cavitation from 1.5 W/cm2up to 2.5 W/cm2and in the process of cavitation disintegration of liquid mixing in her fall asleep and mix the cement, at the same time with fill fluid mixing in a mixer-activator also pour remaining from the settlement (RX) dose of the fluid mixing in the mixer with a placeholder, which use water, which is in the process of pouring concrete mixer with placeholder Magnificat, which it passed with a speed of (1÷2) m/s through a transverse magnetic field, the intensity of which lies in the range (500÷2000) uh, then after stirring the slurry (cement grout) in a mixing activator for 1-1,5 min, it is poured into a mixer and the resulting mixture was finally stirred for 1.5-2 minutes



 

Same patents:

FIELD: chemistry.

SUBSTANCE: invention relates to construction, particularly to a method of producing heat insulating material based on wood processing wastes. The method of producing heat insulating material involves mixing solution-pretreated wood aggregate, portland cement, an additive and water, followed by moulding and hardening. The wood aggregate used is industrial chips. The solution used to treat the aggregate is 30% sodium glass solution in amount of 10% of the weight of the wood aggregate. The portland cement used is based on portland cement clinker with ultimate strength of 40 MPa, which is premixed with the additive which is in form of powdered calcium chloride with weight content of calcium chloride of at least 90% and in amount of 2% of the weight of portland cement. After mixing said components with water, the mixture is further mixed with process foam from an aqueous solution of 1% protein hydrolysate, with the following ratio of components, wt %: industrial chips - 38-40, said sodium glass solution - 3.8-4.0, portland cement - 39-42, calcium chloride - 0.3-0.36, said process foam - 0.8-0.85, water - the balance. The material is moulded in a press mould at pressure of 0.1÷0.35 MPa, followed by hardening at temperature of 50÷60°C and relative air humidity of 70÷80%. After hardening, a cladding is deposited, the cladding consisting of a polyol and a polyisocyanate, with the following ratio of components, wt %: polyol - 55, polyisocyanate - 45.

EFFECT: low density of the material and improved heat insulation properties thereof.

1 dwg, 1 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to the industry of construction materials and specifically to methods of preparing a concrete mixture. The method of preparing a concrete mixture involves measured feeding into a concrete mixture of cement, aggregate and hardening liquid, followed by agitation of said mixture. The disclosed method is characterised by that before feeding cement into the concrete mixture, the cement particles are charged with a positive or negative electrostatic charge by passing them through a mesh electrode across which a high negative or positive potential is applied, the magnitude of which lies in the (8-10) kV range. The hardening liquid used is activated water, wherein if the cement particles are charged with a negative electrostatic charge, the activated hardening liquid is an anolyte having redox potential (Eh)an in the range of [250≤(Eh)an≤1200] mV, and if the cement particles are charged with a positive electrostatic charge, the activated hardening liquid used is a catholyte having redox potential (Eh)cat in the range of [-820≤(Eh)cat≤300] mV.

EFFECT: more efficient use of cement and high strength of the hardened cement, as well as faster setting of the cement.

2 tbl, 1 dwg

FIELD: process engineering.

SUBSTANCE: invention may be used for making concrete mixes, mortars and other mixes containing cement. Method of processing puzzolanes including slag and flue ash such as Class F and/or Class C comprises subjecting puzzolanes to high-intensity grinding in appropriate grinders. Note here that low-density hollow particles as larger particles of slag get decomposed to activate surface of said particles to make finished product feature the following distribution of particles by sizes (in wt %): ≤5 micron - 15-25, ≤10 micron - 30-40, ≤30 micron - 90-95. Invention is developed in its subclaims.

EFFECT: higher activity of puzzolanes and strength of construction materials.

7 cl, 3 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to production of concrete filler and the industry of building materials and can be used in producing concrete or mortar used in making concrete and reinforced concrete articles and structures for prefabricated and monolithic construction. The method of producing dry concrete filler involves separating the 0-40 fraction, re-grinding in a grinding apparatus the product of grinding the fraction larger than 20, and separating and dispersing the 0-20 fraction. Further, the product of grinding the 0-40 fraction is activated in two steps. The first activation step is carried out in a drying apparatus and the second step is carried out in a grinding apparatus: particles of the 2.5-40 fractions are cubed and particles of the 0-2.5 fractions are granulated. When separating the 0-20 fraction, along with known fractions 15-20; 10-15, the 3-10; 0-3 fraction is selected and the 0-3 fraction is dispersed on an air classifier with separation of the 1.25-3 fraction; along with known fractions 0.63-1.25; 0.31-0.63; 0.16-0.31, 0-0.16. An area for producing dry concrete filler using the disclosed method is also described.

EFFECT: obtaining high-quality dry concrete filler with high environmental friendliness of production.

2 cl, 1 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing gypsum binder. The method of producing gypsum binder by dry processing of starting material which is phosphogypsum and/or gypsum rock and a modifying additive, involving mixing, heat treatment and grinding the starting material under the action of an external alternating electromagnetic field in the frequency range of 10-1000 Hz with field strength of up to 100 kA/m in the presence of magnetic-susceptible granular filler with further separation of the obtained dry powder into gypsum binder and magnetic-susceptible granular filler.

EFFECT: high quality of the obtained product, simple technique of production and low power consumption.

11 cl, 7 tbl, 7 ex

FIELD: chemistry.

SUBSTANCE: invention relates to the industry of structural materials and can be used when making construction products and structures from acid-resistant concrete. In the method of producing acid-resistant concrete, involving preparation of an aluminosilicate binder component, feeding an aggregate and binder components, mixing, moulding articles, ageing and subsequent solidification thereof, the aggregate used is a waste ash-slag mixture from Irkutsk TPP-6, Bratsk, with packed density ρ=1200-1450 kg/m3, grain size of 0.315-10.0 mm and moisture content of 1-1.5%, with the following ratio of grains of fractions, %: 10 mm - 9.9; 5 mm - 49.6; 2.5 mm - 10.2; 1.25 mm - 13.9; 0.63 mm 10.6; 0.315 mm - 5.8; the binder used is alkaline-ash binder consisting of 35 wt % field I flue ash and 65 wt % field II flue ash, obtained from burning Kansk-Achinsk brown coal at TPP-7 Bratsk, Irkutsk region, and liquid glass made from large-tonnage wastes from production of ferrosilicon at the Bratsk Ferroalloy Plant - microsilica, consisting of 10-15% crystalline and 85-90% amorphous component, with silica modulus n=0.9-1.5 and density ρ=1.3 0-1.42 g/cm3, with the following ratio of components, wt %: said field I ash - 7.30-7.50; said field II ash - 13.05-13.90; said liquid glass - 14.40-16.70; said ash-slag mixture - 62.50-64.20; preparation is carried out by grinding the aluminosilicate component in a ball mill for 15 minutes; the articles are moulded by vibration, after which they are held for 3 hours at temperature T=18-22°C, and solidification takes place in a steam treatment chamber at temperature T=85-90°C in a 2+4+2 hour mode.

EFFECT: low steam treatment temperature of articles and faster solidification, wider range of crude components.

6 tbl

FIELD: chemistry.

SUBSTANCE: method of producing a wet concrete composition, including a step of mixing: portland clinker in form of grains having Dv97 from 10 to 30 mcm or having a Blaine specific surface of not less than 5300 cm2/g, preferably not less than 5500 cm2/g, the minimum quantity of the clinker in kg/m3 being determined according to formula (V) for clinker having Dv97 from 10 to 30 mcm, or according to formula (VI) for clinker having Blaine specific surface of not less than 5300 cm2/g: [(90 x ln(Dv97k)) - 150] x (Weff - 140) (V) wherein Dv97k is Dv97 of clinker given in mcm, Weff is the quantity of effective water in l/m3; [(-0.021 x BSSk) + 263] x (Weff - 140) (VI) wherein BSSk is the Blaine specific surface of clinker given in cm2/g, Weff is the quantity of effective water in l/m3; - slag, of which the minimum quantity in kg/m3 is determined according to formula (VII) in the case of a mixture with clinker having Dv97 from 10 to 30 mcm, or according to formula (VIII) in the case of a mixture with clinker having Blaine specific surface of not less than 5300 cm2/g: (3500 - BSSS) x [-90 x ln(Dv97k) + 310] x (Weff - 140) (VII) wherein Dv97k is the Dv97 of clinker given in mcm, BSSS is the Blaine specific surface of slag given in cm2/g, (3500 - BSSS) x [0.021x BSSk - 103] x (Weff - 140) (VIII) wherin BSSk and BSSS are respectively the Blaine specific surface of the clinker and the slag given in cm2/g, Weff the quantity of effective water in l/m3; - calcium sulphate; additional materials having Dv90 of not more than 200 mcm, of which the minimum quantity in kg/m3 is determined according to the following formula (IX): 220- (quantity of slag)-(quantity of clinker)-(quantity of calcium sulphate); - 1500-2200 kg/m3, preferably, - 1700-2000 kg/m3 aggregates; plasticiser; - optionally an accelerator and/or an air-entraining agent and/or a thickening agent and/or a retarder and/or a clay-inhibiting agent; with 140-220 l/m3 of effective water, the total quantity of clinker in the wet concrete being not more than 200 kg/m3. The present invention also relates to a wet concrete composition obtained by mixing with water and an object made from the solidified concrete mix.

EFFECT: low consumption of clinker while preserving strength of the concrete.

4 cl, 4 ex, 4 dwg

FIELD: chemistry.

SUBSTANCE: invention relates to the industry of building materials and can be used when making construction products and structures from concrete. In the method of producing concrete, involving preparation of an aluminosilicate binder component, feeding an aggregate and binder components, mixing, moulding articles, ageing and solidification thereof, the aggregate used is screenings from grinding diabase with crushing strength Cr=8, packed density ρ=1560-1585 kg/m3 and fineness modulus Mf=3.6-3.9, with the following ratio of fractions, %: 5-10 mm - 15.1-47.3, 1.25-2.5 mm - 22.8-33.1, 0.315-0.63 mm - 7.8-46.2, 0.14 mm and less - 4.0-16.3, and the binder used consists of 50 wt % field II flue ash and 50 wt % waste ash-slag mixture obtained when burning brown coal from KATEK at Bratsk Thermal Power Plant, and liquid glass produced from large-tonnage ferrosilicon wastes from Bratsk Ferroalloy Plant - microsilica, with packed density of 180-200 kg/m3 and containing up to 10-15 wt % impurities, with silica modulus n=0.9-1.3 and density ρ=1.28-1.42 g/cm3 with the following ratio of components, wt %: said field II flue ash 10.75-10.94, said waste ash-slag mixture - 10.75-10.94, said diabase screenings - 64.50-65.64, said liquid glass - 12.48-14.00; preparation of the aluminosilicate component involves mixed grinding in a ball mill of ash and the waste ash-slag mixture for 20 minutes; moulding is carried out by vibration, after which ageing is carried out for 6 hours in air-dry conditions at temperature of 18-20°C, and solidification is carried out by steaming at temperature of 85°C in the 2+4+2 hour mode.

EFFECT: high strength of the concrete and shorter duration of the technological process.

8 tbl

FIELD: chemistry.

SUBSTANCE: invention relates to the industry of building materials and can be used when making construction products and structures from acid-resistant concrete. In the method of producing acid-resistant concrete, involving preparation of an aluminosilicate binder component, feeding an aggregate and binder components, mixing, moulding articles, pre-ageing and subsequent solidification thereof, the aggregate used is screenings from grinding diabase containing 5-9 wt % powdery and clay impurities, characterised by crushing strength Cr=8, packed density ρ=1550-1700 kg/m3 and fineness modulus Mf=4.0-3.7, with the following ratio of fractions, %: 10 mm - 12.3; 5 mm - 22.8; 2.5 mm -16.6; 1.25 mm - 7.1%; 0.63 mm - 14.6; 0.315 mm - 15.1; 0.14 mm- 8.2; less than 0.14 mm - 3.3; the binder used is composite ash-alkaline binder consisting of 60 wt % field I flue ash and 40 wt% waste ash-slag mixture consisting of 17 wt % ash and 83 wt % slag, obtained from burning KATEK brown coal at Bratsk Thermal Power Plant, and liquid glass made from large-tonnage ferrosilicon wastes from the Bratsk Ferroalloy Plant - microsilica, containing 1-3 wt % ρ-SiC and 5-7 wt % C, with silica modulus n=1 and density ρ=1.30-1.45 g/cm3 with the following ratio of components, wt %: said field I flue ash 12.9-13.2; said waste ash-slag mixture 8.6-8.8; said diabase screenings 64.5-65.7; said liquid glass 12.4-14.0; the aluminosilicate component is prepared by mixed grinding in a ball mill of the ash and waste ash-slag mixture for 30 minutes to sieve No.008 residue or 0.7-0.8%; articles are moulded by vibration for 1-2 minutes, after which they are held at temperature of 18-20 C in a moist chamber for 3-6 hours, and solidification is carried out by steaming at temperature of 80-85°C and atmospheric pressure for 7 hours.

EFFECT: high acid-resistance of concrete.

8 tbl

FIELD: construction.

SUBSTANCE: mixture according to the invention may be produced so that a) at least one quarternary organic ammonium compound and at least one water soluble organic polymer are mixed with each other in water and optionally the produced water mix is then dried, or b) at least one powdered quarternary organic ammonium compound and at least one powdered water soluble organic polymer are mixed with each other, or c) at least one liquid and/or dissolved quarternary organic ammonium compound is applied onto at least one powdered water soluble organic polymer, in particular, with the help of spraying, adsorbing, mixing, drying in a pseudofluidised layer and/or granulation.

EFFECT: elimination of fading of construction materials with preservation of their physical and mechanical properties.

17 cl, 4 ex, 2 tbl

FIELD: ceramic binder and ceramic materials made from the same.

SUBSTANCE: ceramic binder is obtained by thermal treatment of raw materials containing (mass %) clay (e.g., clay waste) 20-45; limestone (e.g., limestone waste) 5-30; and ash (e.g., ash from thermoelectric plant) 25-75, at 900-11500C. Method for production of ceramic materials using the claimed binder includes mixing of raw materials, forming, and thermal treatment at 174-2100C under pressure of 0.8-1.6 MN/m2 in saturated water steam.

EFFECT: low-cost ceramic materials with reduced volume weight and high mechanical strength.

2 cl, 3 ex, 3 tbl

FIELD: manufacture of building materials.

SUBSTANCE: quick-hardening bound cement mortar including, vol parts: cement 6-9, water 2-3, aqueous epoxide resin dispersion 1, and hardener 1, said cement being of quick-hardening type and said dispersion additionally containing polyurethane rubber. Quick-hardening cement can be alumina-based cement. In a method of preparing quick-hardening bound cement mortar including mixing cement with aqueous epoxide resin dispersion and hardener on a surface immediately before underwater application, one volume part of water is diluted with one volume part of hardener and stirred, after which one volume part of aqueous dispersion of epoxide resin and polyurethane rubber are added, resulting mixture is agitated and then, depending on particular application, 1 or 2 vol volumes of water are added and, after agitation, resulting composition is used to temper quick-hardening cement, and stirred in low-speed mixer until soft plasticine-type plastic homogenous mass is obtained, after which mortar is held up to 5 min and agitated once more. Escort method of repairing concrete and reinforced concrete underwater structures comprises conveying quick-hardening cement mortar into underwater repair operation zone and manually laying thus prepared mortar onto prepared surface with defective spots. Conveyance of mortar can be accomplished by means of containers or buckets, or yet by means of worm mortar pumps. Invention enables preparation of repair material characterized by dimensional stability, short setting time and fast hardness development, non-diffuseness in aqueous media, waterproofness, frost resistance, crack resistance, resistance to corrosive media (salt and alkali solutions, petroleum products), high adhesion to cement, concrete, and metallic surfaces, and not leading to corrosion of hardware.

EFFECT: improved performance characteristics of cement mortar.

6 cl

FIELD: no-fines concrete production useful in drainage systems and curb construction building.

SUBSTANCE: claimed method includes mixture preparation containing of Portland cement, water and target additive in wing blender; blending of said mixture with dense coarse aggregate and subsequent laying of obtained concrete mixture. Said aggregate is charged into blender-capsulator, then mixture of Portland cement, water and target additives is fed, and cotreatment is carried out for 1-3 min. Claimed concrete mixture contains (mass %): Portland cement 5-15, said aggregate 82-88, target additive 0-1.0, and balance: water.

EFFECT: simplified technology of no-fines concrete; concrete of improved quality.

3 ex, 1 tbl

FIELD: manufacture of building materials.

SUBSTANCE: method consists in preliminarily affecting only tempering water directly in supply tank of concrete-mixing unit by means of high-voltage electric discharges emerging in interelectrode spaces of electrode system followed by adding chemical additives before mixing tempering water with binder and fillers, all operations being accompanied with active agitation of with mechanical agitator driven from electric motor.

EFFECT: considerably shortened total mixing time, improved quality of mix because of more evenly distributed activated water molecules and chemical additives, and reduced consumption of power on activation of water.

1 dwg

FIELD: manufacture of building materials.

SUBSTANCE: method consists in preliminarily affecting only tempering water directly in supply tank of concrete-mixing unit by means of high-voltage electric discharges emerging in interelectrode spaces of electrode system followed by adding chemical additives before mixing tempering water with binder and fillers, all operations being accompanied with active agitation by means of air bubbles bubbling through water, e.g. from gas collector with nozzles supplied with air from compressor.

EFFECT: considerably shortened mixing time, improved quality of mix, and reduced consumption of power on activation of water.

1 dwg

FIELD: manufacture of large-size cement-fiber plates used for facing buildings and making roof covering.

SUBSTANCE: method comprises steps of mixing cement, sand, micro-filler, reinforcing synthetic fibers, plasticizing additive and water; shaping and drying; using wollastonite as micro-filler. At first in turbulence mixer dry loose components such as cement, sand, wollastonite are mixed. Then reinforcing synthetic fibers are added and composition is mixed. Plasticizing additive and water are added at next relation of ingredients, mass.%: cement, 68 -81; sand, 9.5 -13.5; wollastonite, 9.25 - 12.50; synthetic reinforcing fibers, 0.16 -0.55; plasticizing additive, 0.38 -0.43; water, the balance. Articles are dried in air in natural condition. Polypropylene fibers are used as synthetic reinforcing fibers. Mixing of cement, sand and wollastonite in turbulence type mixer is realized during time period no more than 30 s at using water heated up to temperature no lower than 40°C. Size particle of wollastonite is in range 100 -170 micrometers.

EFFECT: enhanced quality of plates.

5 cl, 1 ex, 1 tbl

FIELD: building materials, particularly for forming heat insulated and structural heat insulated articles, for forming cast-in-place heat- and noise-insulation floor panel filling of cellular concrete.

SUBSTANCE: method involves preparing cellular concrete mix; pouring the mix into mold or formwork; applying additive on cellular concrete mix surface; treating the surface layer with device having rotary disc provided with needles variable in length and heat treating the concrete mix. Cellular concrete mix is prepared with the use of composite gas-foam pore former in tubular mixing means during cellular concrete mix heating up to 45-65°C. Additive is applied on convex concrete surface just after cellular concrete mix heaving. Fibrous agent and/or water-soluble component taken in amount of 2-8% of the cellular concrete mix weight is used as the additive. The surface layer has 2 cm thickness. Disc comprises needles gradually decreasing in length from disc center to periphery thereof. Fibrous agent is asbestos, wool, rock wool and polymeric fiber waste. Water-soluble polymer is polyvinyl acetate, polyvinylchloride, polysterene or polyacryl.

EFFECT: improved service characteristics of the ready article, reduced time of production due to optimal combination of above mix preparing and mechanical surface treatment operations.

3 cl, 1 tbl

FIELD: construction.

SUBSTANCE: method comprises supplying water and cement or water, cement, and sand to the cavitation mixer, mixing the ingredients in the presence of an activator during 5-15 min, introducing the dry blowing mixture to the solution produced, and further mixing during 15-60 s. The dry blowing mixture is composed of, in mass %, 70 of cement, 12 of pigment aluminum powder, 12 of water-soluble aluminum powder, 2 of antifreeze plasticizer, and 4 of water.

EFFECT: reduced cost and enhanced efficiency.

4 tbl

FIELD: manufacture of building materials.

SUBSTANCE: invention relates to manufacture of polystyrene-concrete parts for use in construction as wall and heat-insulating material. Manufacture of heat-insulation products comprises preparation of molding mix from Portland cement (60.0-65.6%), water, and granulated foamed polystyrene with loose density 10-20 kg/m3 (2.2-4.4%), molding, and heat treatment of products. Invention resides in that molding mix additionally includes microsilica (6.6-12.0%) and superplasticizer S-3 (0.6-0.66), starting mix Portland cement/microsilica/foamed polystyrene is first stirred for 2-3 min, then water containing superplasticizer is added, resulting mix is stirred for further 3-5 min and loaded into molding boxes. Molding involves vibrocompaction and pressing followed by unloading of products from molding boxes and heat treatment: 2 h at 15-25°C, 8 h at 40-60°C, and 1 h at 15-30°C.

EFFECT: reduced consumption of cement, improved placeability and moldability of mix, increased strength of products, and increased productivity.

2 tbl

FIELD: construction industry.

SUBSTANCE: the invention is pertaining to the field of construction industry, in particular, to the production of glass containers, in particular, to the methods of production of an items out of a concrete mix, which may be used in municipal landscape improvement of overall decor accomplishment of the modern town-planning in the form of the decorative fencing, lawns, roads, gardens in front of buildings, flower beds, at paving of territories and in other cases of the landscape design. The technical result is production of the items with a high strength, life duration, frost-resistance, increased chemical durability, watertightness, cement saving due to substitution of its optimum amount for microsilica. The method of production of an item our of a concrete mixture provides for preparation of concrete mixture by stirring of cement, sand, an pigment of organic or inorganic generation, C-3 superplasticizer and water with the subsequent laying of the concrete mixture in the form with an relief insert, placing the form on a molding table, compaction by vibration. At that they use sand with the grade modulus of Mgr-2.4-3.2. The concrete mixture is added with microsilica, and components take in the following ratio (in mass %): cement - 19.5-22.0, the indicated sand - 69.0-69.2, the indicated pigment - 0.7-1.0, C-3 superplasticizer - 0.1-0.21, microsilica - 1.0 3.4, water - the rest. At that first they stir the indicated sand and the indicated pigment for 45-50 seconds, then this mixture is added with the cement and microsilica and again the mixture is stirred during 60-70 seconds, then it is added with water with C-3 superplasticizer and the mixture is stirred for 120- 180 seconds, and compaction by vibration is carried out for 1-2 seconds with the subsequent simultaneous compaction by vibrations and pressure of 10-15 atm during 6-15 seconds. After that the newly formed item is placed in the chamber of the hygrothermal treatment with the temperature 0f 17-23°C and the relative humidity of 90-100 % and keep there for 15-20 hours. At that the form is made out of a steel and the figure inserts are made out of polyurethane.

EFFECT: the invention ensures production of the items with a high strength, life duration, frost-resistance, increased chemical durability, watertightness, cement saving due to substitution of its optimum amount for microsilica.

2 cl, 3 tbl, 1 ex

Up!