A DAMPNESS-REMOVING CONSTITUENT UNIT FOR MASONRY SYSTEMS

Abstract: A dampness-removing constituent unit (1) for masonry systems, which is intended both for reclamation interventions and for prevention of dampness formation, in particular of the rising dampness, said constituent unit (1) being made up of a brick- or tiles material or of concrete, and consisting, in succession from its upper surface, of a first layer (2) which is made up of a homogeneous brick- or tiles material, a layer of resin material (3), a second layer made up of a brick- or tiles material (4) and having a continuous top portion and a lower portion (5) in which some alternate longitudinal holes (6) are provided which have in their upper portion some longitudinel metallic bars (inserted into the constituent unit (1) or connected to the same by means of supporting members) which are intended for priming the electroosmotic phenomenon.

Description: This invention relates to a constituent unit for the prevention of dampness formation in masonry systems. More particularly this invention relates to a dampness-prevention constituent unit which is intended both for restoration of masonry structures and for prevention of dampness formation in newly built masonry structures. This invention is more particularly intended for solving problems causes by capillary rising dampness, as opposed to dampness caused by rain or by condensation, and in a particular way both for the physical type effects and for the chemical type effects arising in the masonry itself. As is well known, the rising dampness level depends on the compactness degree of the material as well as on the priming absorption degree. Various and different means have been adopted up to now to counteract the bad effects caused by dampness in masonries and to prevent its formation. Thus, the British Patent Specification GB-A-259101 discloses bricks or blocks having a number or grooves and channels forming a series of open-ended air passage through the wall of the building, the inner ends of these passages communicating with the space below the floor or directly with the airspace in the floor all around the building. These bricks or blocks clearly do not prevent the formation of dampness but serve to discharge the condensation or infiltration water into the ground below the floor or around the building. Moreover, such bricks do not prevent the capillary rising dampness which within a certain time will penetrate the masonry material arranged above the channaled bricks. There are know some methods used for blocking the capillary dampness. One of many such methods which could be mentioned is the so-called "wall-partition method" that contemplates the insertion of resins or metallic plates which comprise a barrier preventing water from ascending. Such a method, though a safe operating principle from the theoretical standpoint as regards the problem of capillary rising, is also affected by remarkable drawbacks which are due in particular to the method employed for installation. Indeed, it is difficult to check whether the arrangement of the resin inserts has been carried out in the best way by means of well connected and welded joints, so as to warrant the presence of a homogeneous masonry. Moreover, the metal oxidation phenomenon in case of adoption of metallic plates, or the resin depolymerization by the action of atmospheric agents often give rise to the breaking or cracking of the material in contact with water so as to damage its functional properties. Finally, such method is also affected by the drawback that when the resin layers are put directly in contact with the masonry, the shrinkage and the different expansion with respect to the masonry itself are often a cause of breaking or crumbling of the masonry material and/or of the dampness-removing material employed. Even in systems in which the resin is injected under pressure or by a slow transfusion, as in the Peter Cox method, often a depolymerization of the materials occurs . Moreover, both by the method of injection under pressure and by the method of the slow transfusion of the material, the drawback can occur consisting in an incomplete filling with such materials or, in the case of the first-mentioned method, the drawback consisting in the breaking of the capillary tubes with the consequent formation of pits of larger sizes, in which a larger amount of water becomes concentrated. Alternatively, in order to limit the phenomenon of dampness rising up the capillary tubes, the electroosmosis method is employed, which consists in creating an electric polarity inversion between the soil and the masonry, so as to invert also the path of the water particles and to direct them from the masonry itself towards the soil. This is generally performed by inserting copper electrodes into the masonry. One of the biggest drawbacks of such system is the oxidation of the metallic members which, if positioned improperly, damage the operating properties of the system. The removal and exhaustion of dampness from masonries by means of such system is anyway affected by the drawback of requiring a particularly long time and, as a consequence, of failing quite often to give the desired effects. Moreover, this phenomenon only occurs if strong dampness concentrations are formed, and it stops when the percentage of the dampness diffused in a masonry is still too high for the wall to be accepted as hygienically suitable. On the contrary, the use of siphoning devices, and in particular of the method by Knapen, has the drawback of making reference to a member which is so inserted into the masonry as to cause the hole in the masonry itself not to be in direct contact with air. Moreover, it is inserted at such a slope as to perform its effective operation just under some atmospheric conditions. The methods mentioned above, like other methods already known in the prior art, result from a theoretical standpoint in efficient systems for restoration and prevention of dampness formation in masonry structures, are affected by remarkable limits in their application, because they all consist in interventions which are carried out directly on the masonry. Moreover, taking into consideration the specific character of the installation systems, it is quite often impossible to perform restoration works by summing together the effects of different methods. Accordingly, there is an evident need for a dampness removing system endowed with a high degree of adaptation to the various masonry systems, which system should allow a rapid exhaustion of dampness, and should be easily usable both for restoration works and in new buildings for prevention purposes; such system should also remove all installation problems typical of the methods described above and all functional drawbacks connected to such methods. In order to meet such requirements, the present invention suggests a restoration and prevention method against dampness, which method makes use of a masonry constituent unit derived (as regards its conformation) from the baked brick, which unit has morphological and functional properties that allow, together with the other adjacent constituent parts, a homogeneous barrier to be created, by means of which the formation of dampness can be obviated through the employment of both the electroosmosis principle and the thickness-decrease system, as well as through the employment of the aeration, the siphoning, and the resin insertion systems, this last being applied simultaneously with the formation of the constituent unit made up of a lattice grid or a resin plate. Moreover, again according to the present invention, the realization is suggested of a building constituent unit which, in addition to perform the restoration function, can also perform an aesthetic function in masonries in which it is inserted. More particularly, the dampness-removing modular constituent unit of this invention exerts its dampness-removing function due to the presence of resins which are introduced in such article at the moment of formation of the same, such resins being distributed throughout the article itself in a homogeneous way, as well as to the contribution of the electroosmotic process that occurs owing to the presence of metallic members arranged in the portion of the constituent unit itself that shows a higher dampness density, to the presence of grooves or channels which are similar to siphons inside which a circulation of air streams occurs (with respect to a neutral axis), and to the decrease in the contact surface between the basis of the masonry and that of said constituent unit. Again according to the present invention, provision is made so that, thanks to the arrangement of the resin layer inside each component, the barrier against the capillary rising which is so formed has some discontinuity points which allow the residual dampness amounts that can be exhausted by evaporation to pass, so avoiding the danger of stagnation in the masonry portion below the barrier itself. Moreover, again according to the present invention, the particular arrangement of the metallic members in the upper portion of the aeration holes, which arrangement is connected to the possibility of causing hot air streams to circulate through the holes themselves, favours the removal of water particles under strong dampness conditions. These objects are achieved by a masonry constituent unit for the prevention of dampness formation, comprising some bricks having a number of channels at their lower surface, characterized in that each of said bricks comprises an upper layer consisting of a brick or tiles material, a central mediate layer of resin material and a lower layer of a brick or tiles material, having a continuous upper portion and having a number of channels provided at its lower surface and separated one from another by walls and bar-like metallic elements fastened by suitable supporting members to the upper portion of said channels,said resin material layer having a surface area smaller than the surface areas of said upper and lower layers and being arranged centrally with respect to the upper and lower layers to leave the perimetrical marginal portions thereof in contact with one another. According to a preferred embodiment of this invention, the masonry constituent unit according to this invention can also have a third homogeneous, brick or tiles material layer, a second resin layer and a fourth layer of brick or tiles material endowed with longitudinal channels, at a position below said second brick or tiles material layer. Advantageously again according to this invention, said channels provided in said second and in said fourth longitudinal layer have cross sections in the shape of an Ω, of a triangle, of a trapezium, or of a square, according to the aesthetic requirements. Advantageously such channels, in addition to allow metallic bars intended for favouring the electroosmotic phenomenon to be fastened through hooks, also favour the evaporation phenomenon by aeration or ventilation down to the innermost layer of the masonry itself. Indeed, as the capillary tubes of a masonry behave like a water pipe, an increase in the rising speed occurs simultaneously with a pressure drop and a strong lateral friction on the walls, with some deposition of salts and a decrease in the cross section of the capillary tube so as to stop or to slow down the rising of water. Moreover, the particular morphological configuration of the constituent unit causes a decrease in the thickness of the contact area with the liquid stream and hence of the zone in which the absorption occurs; accordingly, depending on the different masonry thicknesses, preferably a number of longitudinal through channels are provided whose length is equal to half the longitudinal size of the brick. It is an alternative kind of embodiment of this invention, a masonry constituent unit having an insulating material in its inside portion, said material being of the thermoacoustic type or of any other type, and not endowed with channels. Moreover, again according to this invention, the masonry constituent unit is made up of brick or tiles material or of concrete so that a uniform porosity is kept throughout the masonry. Finally and again according to this invention, said resin layer arranged between said first and said second brick or tiles material layer is made up of a lattice grid or of a resin or polymer layer, such layer being inserted after baking the brick which is divided into two parts when it is molded, which parts are then joined by means of an adhesive agent. (The resin can be inserted into the concrete constituent unit already after pouring the mixture into the mold, because there is no successive baking). According to an alternative embodiment of this invention, the resin grid can be introduced by imbibition or by absorption-impregnation, and arranged within the article or at a position close to the surface of the same. This invention will be now disclosed just for illustrative and not for limitative purposes with reference to the enclosed drawings, wherein: Figure 1 shows an exploded axonometric view of the masonry constituent unit according to this invention without the metallic members in the lower part of the channels; Figures 2A, 2B, 2C and 2D show a front cross-sectional schematic view of the masonry constituent unit according to this invention, with various cross-sectional shapes of the longitudinal channels; Figures 3A, 3B and 3C show a vertical cross-sectional view of the side portion of the masonry constituent unit according to this invention; Figures 4A, 4B, 4C and 4D show a vertical cross-sectional view of the side portion of the masonry constituent unit according to the present invention, of the double type; Figures 5A, 5B, 5C and 5D show a front schematic view of various different installation systems of the masonry constituent unit B65 according to this invention. As can be observed in Fig. 1, the masonry constituent unit 1 is essentially made up of three layers: a first, brick- or tiles material layer 2, a layer 3 which is made up of a resin grid, and a second layer 4 which is made up of a brick- or tiles material. The layer 2 and the layer 4 are next connected by means of solidifying materials after interposing the grid or resin layer 3. This last layer shows, with respect to the lower surface of the layer 2 and to the upper surface of the layer 4, a lower surface area, so that the edges of the two concrete layers turn out to be in direct contact. The lower layer 4 rests directly on the masonry at the points corresponding to the portions 5 of the spacing members delimiting the longitudinal channels 6. A small support tooth (not shown in Figure 1) is provided in the upper portion of each one of said spacing members, a metallic longitudinal member 7 being connected to said small tooth, said metallic member being intended for creating together with the soil the electric field through which the migration of the water particles from said masonry to the soil occurs. The cross section of the longitudinal channels 6, as can be observed in Figures 2A, 2B, 2C, 2D, can be of different types according to the masonry kind and to the aesthetic effect that is to be obtained. Anyway, it is to be remarked that the volume of such cavities keeps substantially similar in each one of the various different kinds of embodiment illustrated in Figures 2A-2D. Figures 3A, 3B and 3C illustrate on the contrary a vertical cross section side view of the masonry constituent unit, in which view it can be remarked that the longitudinal cavities 6 can develop similarly to the whole modular member (Figure 3A), or just partially (Figures 3B and 3C). Figures 4A, 4B, 4C and 4D illustrate some alternative kinds of embodiment of the masonry constituent unit, such embodiments being made up of four overlapped layers of brick or tiles material, in which views it is possible to remark that the holes 6 have different longitudinal sizes. Finally, Figures 5A, 5B, 5C and 5D illustrate some different kinds of positioning and arrangement of the masonry constituent unit 1 for performing the function of a simple and of a double wall-partition system respectively. According to some alternative kinds of embodiment of the masonry constituent unit according to this invention, the channels have different sizes, reciprocal spacings which are even remarkable, compatible with the static strength and with the degree of dampness-removing power of the member itself. This invention has been disclosed just for illustrative but not for limitative purposes, and it is to be understood that modifications and/or changes can be made to the invention within the scope of the appended claims.

Claims: A masonry constituent unit for the prevention of dampness formation, comprising some bricks having a number of channels at their lower surfaces, characterized in that each of said bricks comprises an upper layer (2) consisting of a brick or tiles material, a central mediate layer (3) of resin material and a lower layer (4) of a brick or tiles material having a continuous upper portion and having a number of channels (6) provided at its lower surface and separated one from another by walls (5) and bar-like metallic elements (7) fastened by suitable supporting members to the upper portion of said channels, said resin material layer having a surface area smaller than the surface areas of said upper and lower layers and being arranged centrally with respect to the upper and lower layers (2 and 4) to leave the perimetrical marginal portions thereof in contact with one another. A masonry constituent unit according to claim 1, characterized in that it has, at the points corresponding to the lower surface of said second layer of brick- or tiles material, a third layer of a homogeneous material, a second resin layer, a fourth layer of a brick or tiles material which is endowed with longitudinal channels. A masonry constituent unit according to claims 1 and 2, wherein said channels which are provided in said second and in said fourth layer of brick- or tiles material, have Ω-shaped cross sections. A masonry constituent unit according to claims 1 and 2, wherein said channels provided in said second and in said fourth layer of brick or tiles material have triangular cross sections. A masonry constituent unit according to claims 1 and 2, wherein said channels provided in said second and in said fourth layer of brick- or tiles materlal have square cross sections. A masonry constituent unit according to claims 1 and 2, wherein said longitudinal channels provided in said second and in said fourth layer of brick- or tiles material have longitudinal sizes equal to the size of the constituent unit itself. A masonry constituent unit according to claims 1 and 2 wherein said longitudinal channels provided in said second and in said fourth layer of brick- or tiles material have sizes equal to half the longitudinal size of the constituent unit itself.

Inventors: BIANCHI, PASQUALE
Applicants: BIANCHI, PASQUALE
Application year: 1990
Main classification: E04B1
IPC codes: E04B1