MXPA05007970A - Open-cell mortar for acoustic applications. - Google Patents

Abstract

The purpose of the present invention is to use the properties of some natural materials characterised in that they have a porosity known as open-cell porosity, and generate small intergranular volumes randomly arranged, i.e., both the porosity cavities and the intergranular cavities of the present invention include air molecules which are vibrated about their balance position due to sound vibrations, thus producing collisions against the material walls, and transforming the vibration energy into heat which reduces the vibrations amplitude and the energy thereof, thereby substantially reducing sound levels in buildings. The material grain selection, attained by granulometric selection, is an important factor since small intergranular volumes are obtained so as to produce an open-cell effect, thus simultaneously increasing the dampening coefficient. Vibrated blocks for construction have been designed with the present mortar, the blocks being applied in previously or recently constructed buildings, and provided with a sound insulation dampening coefficient that increases loses by transmission, and an inner dampening coefficient that reduces the energy of sound vibration without being modified, thus reducing the persistence time thereof, and substantially improving the intelligibility.

Description

MORTAR FOR OPEN CELDILLA ACOUSTIC APPLICATIONS OBJECT OF THE INVENTION The present development on the basis of a mortar with open cell volcanic gravel, has as its purpose that upon striking a sound vibration oscillates around its equilibrium position the air molecules used as the fluid in which the waves propagate, converting the dynamic energy of the vibration into heat energy, reducing its amplitude in sound pressure and consequently its energy.

For the realization of acoustic conditioning, by reducing the energy of the sound pressure variations, the persistence time of the sound in the enclosures is reduced adapting these according to its application according to the technically called reverberation time according to the needs of its application.

BACKGROUND Constructive materials are generally developed from the constructive point of view, but not for acoustic applications. There are similar materials on the market, but not with sound deadening properties, that is, what is intended in this development is the damping of sound vibrations that corresponds to the reduction of the amount of energy that the vibrations have, converting energy from the vibration in heat, in such a way that the mortar behaves like a transducer, passing energy from vibration to heat. Additionally, materials have been developed with our product that allow a variety of properties in such a way that, as described below, we can eliminate noise, acoustically isolate the enclosures, dampen the signals and finally, adapt the cloisters according to their use. The manufacture of materials of this type, usually called vibrated mortar blocks follow a procedure similar to that of some of the materials developed by us, however, the fundamental difference with ours is the use of an open cell mortar whose properties for Our applications are fundamental for the purposes described. At present, noise is a form of pollution, so it is necessary in many cases to acoustically isolate the enclosures as the first stage to achieve good acoustic conditioning, secondly, once this is achieved, it is necessary to have a good sound distribution to the interior, characteristics of sound persistence that solve the problem of intelligibility and finally, the elimination of some sound effects such as: echoes, resonances, establishment of standing waves, and in many cases too intense noises that produce discomfort in the human organism , so that the present development solves all these effects to a great extent, which has not been contemplated in the materials usually used for exclusively constructive purposes. There are effects that currently have to be taken care of in installations destined to theaters, music halls, recording rooms, cinemas, auditorium churches, sports halls that are not observed in buildings and whose effect reduces to a large extent needs that the current technological advance requires for losing the sonority, harmonic richness, fidelity in the recordings, free areas of mido for the rest which must be taken care of particularly. The materials used do not have the qualities of the mortar for acoustic applications of open cell that is described here, so the difference with the usual materials is considered important.

DETAILED DESCRIPTION OF THE MORTAR INVENTION FOR ACOUSTIC APPLICATIONS. OF OPENED CEDILLA Mortar for acoustic applications of open cell is a mixture of building materials, with multiple applications in the construction industry. The sound waves are mechanical vibrations of low frequency in the range established between 50 hz. or cycles per second and the 16,000 hz that propagate in an elastic medium, which they use as a means of transmission. For our case, this elastic medium is air, in which when the sound waves impinge, they compress and decompress the molecules of the air, that is to say, they increase or reduce locally the pressure of the medium around the atmospheric pressure called static pressure, the which has a value of 760 mm in the mercury slave, which corresponds to a pressure of 1,013 x 105 Newtons per square meter in the system of measurements M S. When a sound wave propagates, the increase or decrease of the local pressure it is a few millionths of the pressure above or below the static pressure, oscillating the air molecules around an equilibrium position does not occur the displacement of the particles with the wave, but they move around its equilibrium position, without net displacement. As the air molecules oscillate, they transmit their energy quantity from one to the other in a successive way, returning them to equilibrium after a short time, when doing it in this way, the sound propagates. The propagation of sound waves in a vacuum does not occur due to this circumstance. This property is used in our development since the greater the sound intensity, the greater the displacement of the molecules of the air around its equilibrium position, if by some mechanism we can reduce the molecular oscillations, we will reduce the amount of energy of the sound waves and we say that the wave is damped.

In our case, if the air molecules are inside an open cell, this is that they are inside a small volume configured by our material, as they move around in their equilibrium position, they find the walls of our cell and they collide with these, transmitting part of their energy to the walls of the material and consequently transmitting part of their energy to them reducing their amplitude and consequently the amount of energy of the sound wave, for which we dampen the sound wave. In figure 11 we show schematically how when the sound waves impinge, the air molecules suffer collisions inside the open cell with its corresponding loss of energy and its consequent damping. A good example is the current microwave ovens which, with vibrations of a much greater frequency, oscillate around their equilibrium position the molecules of the material to be heated and when they collide with each other, they increase their speed which, in turn, causes more collisions between them making a multiplicative process thus increasing the temperature. To this effect of collisions transmitting energy and generating heat is known as the Joule effect, that is, dynamic energy transformation or movement in heat. Figure 12 shows how in the case of ultrasonic equipment heat is generated by collisions between molecules of the material giving rise to the Joule effect. The material used, selected from the gravimetric point of view, ie the size of the grain, generates cavities in the material in addition to the cavities themselves, which causes small volumes to be generated in which the air molecules move freely and they can be reached by the variations in pressure that when put into oscillation by the incidence of the sound wave generate the collisions described above with the consequent loss of energy and its consequent damping that affects the amplitude of the vibrations causing it to be reduced. Due to the need of the cavities of the material due to its volcanic origin which makes it of low density and its dimensions to select it allow us to generate the effect of open cell which produces the desired effect. Figure 13 shows how having the granules of the material their cavities in addition to the cells produced by the dimensions of the granules allow to achieve the desired effect. The fundamental characteristic for the correct operation of this mechanism is that the cavities or open cells always have an opening through which they can act directly on the air molecules in such a way that they are reached by the variations of sound pressure to put them in motion and generate in this way the collisions that allow us to reduce the energy of the vibrations by the loss that occurs when they are hit in the walls of the material. This is achieved, on the one hand, by the same cavities of the material and on the other by defining a uniform granule size, which is achieved with the selection by size of the same. In our case, we have measured that for granules of at most 3mm. in diameter we achieve the desired effect for the usual frequencies of sound waves. Gravel of volcanic origin commonly known as Tepezil, complies with the first condition, the second is achieved with a strict control of the dimensions of the same by careful separation of the granules achieving homogeneous dimensions in such a way that having a random distribution of the eberturas of the cavities, but with an accommodation that is also random but homogeneous is able to produce the intergranular cavities in such a way that allows us to predict with a random mathematical model always have the same order of damping in our materials and be able to offer homogeneous damping coefficients .

This comes in various forms of blocks for acoustic conditioning of the enclosures, in all cases that require an acoustic treatment in the construction, in the form of a block of different thicknesses and dimensions different from what is currently used in the construction industry, as an acoustic resonator for the construction of walls integrating into the resonant cavities , or in bulk, for firm coating adding an absorption coefficient to them, in such a way that the sounds are damped between floors, and that technically the so-called "sound transmission losses" are increased in the construction industry.

Its fundamental application aims to reduce the mechanical vibrations known as sound, so its application is with acoustic shock absorber targets.

The sound intensity in an enclosure can be reduced, reducing the amplitude of the vibrations. The present development consists in using the property of certain natural materials taking advantage of their porosity of the so-called open cell, that is, the porosity of the materials and the intergranular cavities called open cell, with access of the sound waves when the sound vibrations impinge, they oscillate the molecules of the air inside the cell, causing collisions of the air molecules with the walls of the material and transforming the energy of the vibrations into heat technically known as the Joule effect.

The block vibrated see figure 1,2 of dimensions of 0.12 x 0.20 x 0.4 m3 is a block of MORTAR FOR ACOUSTIC APPLICATIONS. OF OPENED CEDULA construction element that benefits from the characteristics of open cell of certain porous materials existing in nature whose density is very low and which selected from the granulométnco point of view, mixed with other construction materials such as binders and construction allow to obtain characteristic special in terms of coefficients of abosorción of mechanical vibrations in the audible range is concerned, particularly employable as materials for acoustic applications in construction. The mechanical vibrations known as sound, are vibrations of low frequency that is to say within the audible range with limits of 50 to 16,000 hertz or cycles per second. In acoustic room conditions it is required in many cases to change the dynamic energy of the vibrations into heat energy in order to reduce the intensity of the sound waves, this is achieved by influencing the vibrations in materials that cause vibrations due to their porosity or fibrousness the molecules of air producing shocks to the interior of the cavities which produce energy losses of the vibration producing heat as a consequence. The use of this property to reduce the intensity of sound waves allows buildings to reduce the persistence of sound vibrations for less time by reducing the so-called reverberation time inside the enclosures. Its application is fundamentally for the damping of sound oscillations inside the enclosures in acoustic conditions of enclosures in such a way to achieve an average absorption coefficient according to the needs to which the premises are destined. Additionally, when talking about acoustic conditioning, there is another complementary theme that refers to the acoustic isolation, that is, the independence from the sound point of view our enclosure of adjacent premises in such a way that the noise generated outside does not enter our room and conversely, in such a way that the so-called losses due to sound transmission increase.

In the energy balance, when a vibration affects a limiting wall, part of the energy is reflected according to Snell's law, the angle of incidence is equal to the angle of reflection, another part of the energy enters the wall and part of the it dissipates superficially, it is the damping effect that we have been describing and finally part of the latter is transmitted to the enclosure, reducing this component are the so-called transmission losses As we have described above, the materials that have the so-called open cell, carefully selected from the granulometric point of view, are materials that have cavities besides that by the selection of the grain from the dimensional point of view produces intergranular spaces with an access to the sound wave of such dimensions that impact sound vibrations with wavelengths of 6.86m for the frequency of 50 hertz or cycles / second considering that the air, acting as the elastic fluid, whose speed of propagation is 343 m / s and 0.0214 m for the frequencies of 16,000 hertz or cycles / second must have lower dimensions so the grain of 0.0030 m diameter is selected in such a way that the granules with air cavities act as transducers converting the dynamic energy of the vibrations or movement in heat energy, the process followed is that when the sound vibrations impinge, they oscillate r around its equilibrium position the molecules of air and these being in motion produce shocks of the same with the walls of the material, when the shocks occur, the molecules lose energy which is transformed into heat that radiates to the environment . This process produces that the reflected wave reduces its amplitude. The energy of a vibration is proportional to the square of the amplitude of the vibration, as a result of the shocks and reduction of the amplitude, and therefore the energy of the vibration, resulting in the reflected vibration having less energy than the incident. If at each relection our vibration reduces its amplitude, in each of them it reduces its energy in such a way that the cells act as shock absorbers of the sound vibrations. This function is the one performed which is equivalent in the energy balance to the superficial reduction of the energy mentioned above.

The addition of mine sand allows us to give our materials a binding element that provides greater rigidity to our materials so that they comply with the norm as far as effort is concerned.

Wealth in cement as a binding element is a very important factor in terms of efficiency, however, by increasing the rigidity of our materials we sacrifice acoustic damping, which is why we must have an adequate proportion in order to maintain our coefficients of sound deadening refers.

The density of the material is of the order of 780 Kg / m3 although the specific density of the same is greater, this results in that our materials are of low density and demand less foundations thus reducing the cost of the work.

MATERIALS USED: Low density volcanic gravel called TEPEZIL 72 dm3 = 56.25 Kg. Portland cement 25 Kg. Mine sand 12 dm3 = 12 Kg. Water 20 dm3 = 20 Kg.

FABRICATION PROCESS Selection of the volcanic gravel by granulometry process with 3.0 mm diameter mesh. Mixing the materials for 10 minutes to obtain a sufficiently homogeneous mixture without lumps or material concentrations. Preparation of molds of the dimensions according to the model in question and for the purposes for which it is intended.

Filling molds and vibrating for 5 minutes in vibrating-compactor machine. Compact of the material by loading 4 Kg / cm2 combined with vibration. PROPERTIES OBTAINED: Sound absorption coefficients by octave depending on mixture and compaction load. The damping coefficients are as indicated above according to the Tepezil grain, the compaction force, the cement load and the amount of sand mine.

With this mortar for acoustic applications of open cell we have designed several products as detailed below, is presented in the form of vibrated partition in dimensions of 0.12 x 0.20 x 0.40 m3 figure 1 and 2 which can be used for the construction of walls with an abosorption coefficient of up to 20 decibels per octave in its face plane form of 0.12 x 0.40 m, of 16 decibels per octave on its face of 0.20 x 0.40 m, It has been designed vibrated block of 0.025 x 0.20 x 0.40 m3 figure 3 and 4 to cover interior walls in housing units in which a balance must be established between sound absorption and minimum decrease of the useful area of the enclosure. It is also presented as a vibrated block of 0.05 x 0.20 x 0.40 m3 figure 5.6 for covering walls with low losses by sound transmission in which it is possible to have a greater reduction in the useful area of the enclosure and require greater acoustic damping . It is presented as a block of 0.12 x 0.20 x 0.40 m3 figures 7.8 with properties that are detailed below with non-parallel walls in order to reduce the so-called normal forms of oscillation of the enclosures, in the same way in the form of resonators. in walls of 0.12 x 0.20 x 0.40m3 figures 9, 10 to reduce the noise generated by low frequencies in particular the voice frequencies in rooms in which sound vibrations are basically produced by voice signals. It is also available in bulk to cover plafond slabs to reduce sound vibrations between floors to increase transmission losses. Additionally, in the form of ceiling for coatings that increase the average absorption of the rooms.

Finally, according to the needs of the enclosures for special applications, we have the capacity to produce other materials according to the needs of the enclosures depending on the needs for the type of sound signals in them, as is known, the characteristics of the rooms in which the reverberation time is concerned depend on the application of the same, when an enclosure is usable for orchestral music the reverberation time must be greater in order to increase 1 persistence of the sound waves than in the case of enclosures in which the prevailing signals are of voice as is the case of theaters or classrooms.

VIBRATED BLOCK of 2.5 x 20 x 40 cm3 figures 3,4 It is a vibrated block of 2.5 cm thickness x 20 x 40 cm, built with our open cell mortar for acoustic applications, it is used for internal coating of dividing walls in which it is necessary to increase the losses due to damping while increasing losses due to the transmission of sound signals in which the dimensions of the premises should not be significantly reduced, particularly in housing units of social interest in which in an area of the order 60 m2 is built a department with all its areas, but in which the sound transmission is important so it is necessary to increase the losses by sound transmission at the same time reduce the amplitude of the sound waves in order to reduce their energy ,, in this case, an average absorption coefficient of 0.15 or higher is sought, which indicates that 15% of the energy inci will be absorbed by our material in such a way that the amplitude is reduced proportionally.

VIBRATED BLOCK of 5 x 20 x 40 cm3 figures 5 and 6 It is a vibrated block of 5 cm thickness x 20 x 40 cms, built with our open cell mortar for acoustic applications, it is used for internal coating of dividing walls in which more space availability is available, as well as increasing absorption losses while increasing transmission losses between dividing walls, in this case, an absorption coefficient of 0.18 will be obtained, that is, at each incidence of the sound wave , 18% of the incident energy will be absorbed superficially by the vibroblocks, in the same way, when covering the surface of the existing wall with these materials there will be an increase in the transmission losses of 18 decibels, that is, the sound pressure transmitted will be approximately 9.5 times less than in the case of the uncoated wall.

BLOCK VIBRATED OF 12 X 20 X 40 cm3 figures 1,2 The vibrated block of 12 X 20 X 40 cm3 figures 1,2 of is an element designed for the construction of both dividing walls and load, for new constructions, which can be employee setting the 20 x 40 plane superimposed on each other. In this case, a 20-centimeter-thick wall with transmission losses of the order of 22 decibels will be available, that is, the external sound waves will be damped in terms of sound pressure in a ratio of 11.5 times the incident pressure so that if you have a sound pressure of 100 times the reference pressure, the transmitted pressure will be only 8.5 the same reference pressure.

It can also be placed by seating the 12 x 40 face in such a way that the resulting wall will have a thickness of 12 centimeters, in which case the transmission losses will be 18 decibels, that is, the pressure incident on one side of the wall will be reduced 9.5 times, as a consequence, if with the previous example there is an incident pressure on one side of the wall, the pressure transmitted will be 11.5 times the same reference pressure.

BLOCK VIBRATED 0.12 x 0.20 x 0.40 m3 stationary wave eliminator. Figures 7,8 The VIBRATED BLOCK of 0.12 x 0.20 x 0.40 m3 of MORTAR FOR ACOUSTIC APPLICATIONS. OF OPEN CEDELLA whose geometry inhibits reflections in the perpendicular to the plane of the material with which it is sought to avoid the normal modes of oscillation of the enclosures that constitute a habitual form of noise in acoustically adapted rooms for use as auditoriums, recording rooms, theaters, churches, sports venues in which generally the existing signals are voice signals or as it is known in the language of low frequency acoustics, in general all the enclosures naturally have the so-called normal modes of oscillation or also known as Stationary Wave (OE) so that with the present design it is desired to eliminate these waves that constitute a form of permanent noise in the rooms.

The application of the OE material seeks to improve the properties of the generic material with reflection properties that eliminate this form of noise.

The design of OE has a geometry that eliminates the possibility of reflection, in the perpendicular to the wall eliminating the successive reflections in the paraleos planes avoiding the standing wave.

The reflections of mechanical vibrations, obey the so-called Snell's Law, this is commonly known as the Law that establishes that the angle of incidence is equal to the angle of reflection, which produces the effect that when inciting a vibration perpendicular to the plane of the wall and have parallel walls, the vibration is reflected perpendicular to the plane and upon finding in its reflection again the opposite wall also perpendicular, the vibration is reflected in the same angle with it the vibration prevails longer in its reflections which results in which becomes a permanent wave for some time which constitutes a form of noise that we call Stationary Wave, for which we designate this model "OE".

By modifying the surface parallel faces of the material, we generate an effect of modifying the angle of reflection in the face, forcing the vibration to reflect in a different direction to the normal one. This reflection produces the effect that when striking the opposite wall, the vibration will not incline perpendicularly and consequently the thickness of the absorbing material that the vibration finds in its reflection increases, consequently increasing the absorption coefficient and consequently increasing the losses of energy in each reflection which allows to cushion our vibration in less time by increasing the losses in each reflection and consequently dampening in a shorter time the vibrations which reduces the so-called Stationary Wave.

BLOCK VIBRATED 0.12 X 0.20 X 0.40 m3 figures 9,10 wall resonator. We start from a model of simple mechanical harmonic oscillator, constituted by an elastic constant represented by a spring, of elastic constant k whose inverse we denominate Mechanical Compliancy Cm = 1 / k to which a mechanical resistance Rm is connected in parallel we use a viscous resistance, this is that the force that opposes the movement is proportional to the speed and a mechanical mass Mm in series.

The force due to the elastic constant is: f = kx = k u dt = (1 / Cm) u dt where u is the linear velocity of the movement. As can be seen in figure 1, the point of union between the three elements moves with the same speed in such a way that the speed of the elements is common. The force due to the mass obeys Newton's Laws and we know that it is equal to mass by acceleration, that is: f = Mm (d2x / dt2) = Mm (du / dt). The force that opposes movement due to mechanical resistance is: f = Rm u, The sum total of the existing forces is: F = Mm (du / dt) + Rm u + (1 / Cm) u (dt) If our speed is a harmonic velocity we have u = u0 e Exp (jwt) which gives us once our equation is developed: F = (Rm + j (wMn - 1 / wCm)) u We define the impedance of the mechanical circuit as: Zm = (Rm + j (wMn - 1 / wCm) On the other hand, we can write that the mechanical impedance is the quotient between force and velocity: Zm = F / u = (Rm + j (wMn - 1 / wCm) The mechanical impedance will be minimal, when the angular frequency w is such that the parenthesis term is zero and we define it as resonance frequency, that is when: w0 = (1 / Mm Cm) 1/2 and in this case the mechanical impedance will be : Zm- Rm being the maximum velocity and equal to u max = F / Rm.

Similarly in electrical circuits we have the series circuit called R, L, C, constituted by an electrical inductance L, commonly known as a coil, an electric capacitor that stores electrical charges also called capacity C and an electrical resistance R that defines the degree of selectivity of the circuit at a certain frequency, see figure as in the mechanical case but now in voltage we have: V = Ri + L (di / dt) + (l / C) i dt As in the previous case, if our electric foundation i is of the harmonic type, the form: i = io e Exp. (jwt) we will have for the steady state: V = (R + j (wL- (l / wC)) i We define in this case an electrical impedance Z which is the quotient of the voltage at current and we have: Z = V / i = R + j (wL - (1 / jwC)) There exists as in the mechanical case a frequency w such that (woL- (l / w0C) = 0 that we call resonance frequency w0 that it cancels the reactive part so that the current is maximum and in this case our electric impedance is only the reasistive part, that is, ZO = R.

Analogously in acoustics, we can make an analog circuit with an acoustic resistance as an element that hinders the flow of air Ra, an acoustic mass as the amount of air contained in a volume of air enclosed in a tube called Ma or acoustic mass and an acoustic elastic constant formed by the air enclosed in a volume of capacity V called acoustic compliance Ca. In our case, we will have the produced sound pressure associated to the circuit is p and whose expression in this case will be: P = (Ra + j (wMa - (l / wCa)) U If, as in the previous cases, we have that the volume velocity is a harmonic velocity of the form U = U0 and exp (jwt) we have for the permanent state, an acoustic impedance Za that equals the ratio of the sound pressure p divided by the volume velocity U remaining in this case: Za = p / U = (Ra + j (wMa- (l / wCa)) By similarity with the mechanical and electrical cases, we have that there is a frequency w such that: (wMa - ( 1 / wCa)) = 0 also called resonance frequency in our acoustic case and equivalent to 0 = (1 / Ma Ca) in this condition the volume velocity U is the resonance that we call Uo = p / Ra which causes that all the acoustic signals of this frequency are eliminated by changing its dynamic energy from the vibration in heat to the interior of our acoustic circuit.

The presence of acoustic resistance produced by filling the cavity that configures acoustic complainance Ca will give greater opposition, less selectivity to our signals to be acoustically eliminated which is the subject of our development. In this way, we constitute an acoustic filter called band eliminator from the technical point of view that we call resonant because it corresponds to the resonance frequency. This circuit is obtained by giving the geometry indicated in the drawing with a polyurethane filling inside the cavity that constitutes our acoustic resistance Ra.

In this case, if a signal of the aforesaid frequency is circulated, having this circuit in a parallel branch thereof, said branch behaves like a virtual earth and the signal upon finding a low impedance path is conducted to ground behave like a short circuit. We will have built a band eliminator filter with central frequency in the resonance filter.

In this case, the cavity with an air intake incorporated in our block, behaves as a signal eliminator of this frequency, greatly reducing the signals emitted in this way. As we have seen in the previous description of Block resonate, from the theoretical point of view, all the mechanical systems have a natural frequency of oscillation which was described when establishing the resonance frequency, using the same principle described above we configure a hybrid block constituted by two blocks, one of 0.025 m. Of thickness and another one of 0.05 m of thickness described previously constituting a sandwich as it is shown in figure 15 which we denominate system mass-spring-mass which to the being of different masses the associated blocks by means of an agglutinate inter-fuel combos of high density configure us an arrangement of two blocks with an intermediate layer of elastic material that allows us to increase the transmission losses, improving the acoustic insulation in the newly created enclosures. Because it is thick, in order to increase the stability of walls, it is necessary to intercalate every five rows of blocks of this type a thin cement chain using a metal ladder between rows. This block is shown in figure 15. BRIEF DESCRIPTION OF THE FIGURES Figure 1 shows an isometric view of the vibrated block material of dimensions 0.12 x 0.20 x 0.40 m3 considering the dimensions, figure 2 isometric of the block seen from another angle which can be used as shown in figure 1 but also as shown in this figure 2, increasing the thickness of the wall built in this way and increasing the damping coefficient. Figure 3, shows an isometric image of the vibrated block of 0.025 x 0.20 x 0.40 m3 from a dimension view and its construction for application in damping of enclosures in which it requires little damping coefficient at the same time of enclosures in which it can not be dispose of important areas to be reduced by its attached to previously built walls. Figure 4 shows isometric of the block with a flat view in which its thickness can be better appreciated. Figure 5 shows a product similar to the previous one, but in this case, the material is 0.05 x 0.20 x 0.40 m3 as in the previous case but applied for enclosures in which the damping needs are greater and more area is available for reduce by its placement. Figure 6 shows isometric of the block in which the thickness of the block can be seen .. Figure 7 shows the product of 0.12 x 0.20 x 0.40 m3 stationary wave eliminator that allows to avoid that the incidence of sound vibrations are reflected in the perpendicular to the plane, in such a way that the successive reflections produce noise by the normal modes of oscillation in the enclosures, figure 8 shows the isometric image of the block in which the eliminating angles of the standing wave are best appreciated. Figure 9 presents the design and dimensions of the mortar for acoustic open-cell resonator applications that allows us to eliminate noise of certain frequencies, in particular the voice frequencies used in sports venues, work rooms or in those cases in which predominant signals are those of voice, figure 10 shows isometric in which the cavities achieved and their entrance to the resonant cavity can be appreciated that as it is appreciated is a cavity opened on both sides, its application is defined according to the frequencies to be eliminated . The higher the frequency to be eliminated, the smaller the number of resonators that will be necessary to place on the wall. Figure 11 shows schematically how to dispose of a porous material called open cell, when the sound waves impact they set in motion the air molecules contained in these cavities, which when colliding with the interior walls of the material transform part of their energy movement in heat by losing part of its energy in the collision. Figure 12 shows, as in the case of microwave ovens, the high frequency vibrations known by this adjective, since they are vibrations of frequencies higher than 100 Khz. they oscillate the element molecules to heat up and cause collisions between them that transform their energy of movement into heat energy producing more and more collisions between them in a multiplicative process that in turn, increases the temperature of the material under treatment. Figure 13 shows schematically how the intragranular cavities are manufactured by a strict selection of these from the point of view of their dimensions producing cavities between them in such a way that when the sound waves impinge they reach the air molecules setting them in motion and producing collisions , likewise, if the pore cavities of the volcanic material have an entrance to it, when the air molecules contained in them are reached by the variations in sound pressure, we obtain a large system of molecules of air in movement with a number of collisions that transform the sound energy into heat producing the sound deadening. Figure 14 schematically shows a block constructed with our open cell mortar, that is to say that the pores of the material and the intergranular volumes contain air molecules that when oscillating and producing collisions lose part of their energy in these collisions in such a way that the The amplitude of the incident wave is greater than that of the reflected wave with the consequent loss of energy and reduction of sound waves over time. Figure 15 shows the constitution of a hybrid block constituted by a block of 0.025 x 0.20 x 0.40 described in figures 3 and 4, 5 and 6, in which a sandwich is constituted by placing between them an elastic material constituting in this way, a block of the so-called mass-spring-mass system. Generally, a layer of polyurethane or fiberglass of 0.025 m thickness is used. with greater losses by transmission. The block indicated with number 1 is a block of 0.05x0.20x0.40 m3, the block indicated with the number 2 is an elastic layer (polyurethane), the block indicated with the number 3 is a block of 0.025x0.20x0.40m3.

Claims (3)

CLAIMS Having sufficiently described my invention, I consider as a novelty and therefore claim as my exclusive property, what is contained in the following clauses:

1. MORTAR FOR OPEN CELDILLA ACOUSTIC APPLICATIONS The open cell mortar is made up of low density volcanic sand (Tepezil) mine sand, prtland cement as agglutinate characterized by a careful selection of the volcanic gravel from the dimensional point of view and built with a pressure at the moment of its manufacture, an accommodation of the granules is made, which configure small volumes called open cells to these intergranular spaces allowing the molecules of the air to be reached by the sound vibrations making them oscillate around their equilibrium position, as a consequence the molecules produce collisions with the walls of the cell changing their dynamic energy into heat energy and as a consequence reducing the amplitude of the vibrations and therefore their amount of energy, reducing the persistence of the sound vibrations in the time property used in the acoustic conditioning . Similarly, for sound insulations, vibrations penetrate the material and as they transmit their energy to the inner layers of the material, they reach the air molecules contained in the open cell, thus reducing the amplitude of the vibrations and rejecting the amount of sound energy transmitted increasing transmission losses, improving the sound insulation. The absorption coefficients are a function of the thickness of the material placed ranging from 10 dB per octave to 30 dB. By octave depending on the thickness. For prefabricated slabs, transmission losses will be 10 dB per octave in 2.5 cm thickness. up to 20 Db. By octave for 8 cm slab coating thickness.

2. The mortar for open cell acoustic applications characterized according to claim 1, for which a vibrated mortar block is made for open cell acoustic applications in the form of a vibrated block of 0.12 x 0.20 x 0.40 m m3 (employable in the construction of new walls to dampen sound signals both in the insulation and in the conditioning of enclosures). The damping coefficient is 0.14 to 125 hz., Which indicates that in each reflection 14% of the incident energy is lost. Which will have a coefficient for 250 hz. is 0.145, for 500 hz it is 0.15, for 1000 hz it is 0.16, for 2000 hz it is 0.17, for 4000 hz the coefficient is 0.18.This block, can be used flat to achieve greater isolation or placed in one of its sides in which case we have less isolation for cases of enclosures located in less noisy areas.

3. The mortar for open-celled acoustic applications characterized according to claim 1, for which a vibrated block of 0.025 x 0.20 x 0.40mm3 is made (used to provide a damping coefficient in previously constructed walls in which it is required a damping and a reduction of the important useful area is not available, particularly in the housing units of social interest). Which will have a coefficient of damping is 0.08 to 125 hz., Which indicates that in each reflection 8% of the incident energy is lost. The coefficient for 250 hz. it is 0.085, for 500 hours it is 0.085, for 1000 hours it is 0.09, for 2000 hours it is 0.10, for 4000 hours the coefficient is 0.12. The mortar for open cell acoustic applications characterized according to claim 1 for which a Vibrated Block of 0.05 x 0.20 x 03.40mm3 is made (used to provide a damping coefficient in previously constructed walls in which a damping is required) and a greater reduction of the useful area is available than in the previous case, particularly in the housing units of social interest). Which will have a damping coefficient of 0.12 to 125 hz., which indicates that in each reflection is lost 12% of the incident energy. The coefficient for 250 hz. it is 0.125, for 500 hours it is 0.125, for 1000 hours it is 0.13, for 2000 hours it is 0.14, for 4000 hours the coefficient is 0.145. The mortar for open cell acoustic applications characterized according to claim 1 for which a vibrated block is made with the geometry of non-parallel walls allows to eliminate certain reflections thus eliminating the so-called standing wave or normal modes of the enclosures and whose dimensions are 0.12 x 0.20 x 0.40 m m3 called standing wave with non-planar faces in one of its planes in order to reduce the perpendicular incidence of vibrations in such a way that the reflections are not continuous and avoid the establishment of standing waves in the enclosures. This block eliminates the standing waves according to the dimensions of the enclosure, above all for use in small-volume enclosures, that is, greater than 100 m3 and less than 1000 m3. The Mortar for acoustic applications of open cell characterized according to claim No. 1 for which a vibrated block of dimensions of 0.12 x 0.20 x 0.40 mm is produced with resonant cavities that allows to eliminate certain frequencies in the enclosures in such a way that they behave as band eliminators in particular voice frequencies in different construction applications. As mentioned in its description, the amount of resonant blocks to be placed is a function of the central frequency that is to be eliminated since, depending on this, it is the volume required in the cavities and the required air intake. The mortar for acoustic applications of open cell, characterized according to claim No. 1, 3 and 4 by the development of a hybrid block by placing between them an elastic material called mass-spring mass system that allows us to improve the losses by sound transmission for acoustic insulation, in order to improve the sound insulation in the newly constructed enclosures El Mortero for open cell acoustic applications Characterized according to claim No. 1, because the cedillas are produced by placing the granules of the previously selected volcanic gravel by separation gravimetric in such a way that small intergranular volumes are created in a random distribution with the particularity that these volumes are reached by the sound vibrations in such a way that the air molecules can be set in motion oscillating around their equilibrium position, producing collisions of is with the walls of the intergranular cells, losing in each collision part of the energy of the oscillation and consequently reducing the amplitude of the same consequently reducing the energy of the waves and at the same time, reducing the persistence of the sound waves in the enclosures, that is, dampening the sound waves in the case of conditioning as well as increasing the energy losses by transmission in the sound insulations.