Process of manufacturing mortar for construction

Abstract: Process of manufacturing mortar for construction (7), intended for forming prefabricated parts as well as being used in bulk, being made from inorganic solids, fly ashes (2) and slags (3), resulting from the combustion of coal in thermal power stations producing electricity, being the aforementioned inorganic solids properly selected and mixed with a small amount of portland cement (8), together with the corresponding part of water (9). If the constructed parts are subjected to thermal treatment, the portland cement will be replaced by a small amount of sodium silicate (10).

Description: The present invention relates to a process of manufacturing prefabricated parts from mortar, such as for instance bricks, jack arches, beams and joists, paving stones, steps and the diverse types known in construction, based on either clay or concrete, being also possible its use in bulk for diverse elements. Various clay-based prefabricated parts are currently known, such as for instance all kinds of bricks, tiles, jack arches, plates, floor tiles, and so on; also known are numerous prefabricated parts made of concrete , such as blocks, plates, beams, steps, paving stones, and so on. The prefabricated parts for construction that are made of clay, have the drawback of their manufacturing costs, since the material needs to be extracted from the beds and properly handled in order to prepare the same for moulding to obtein the part as programmed, a further resultant drawback being the environmental damage produced by the clay beds, since the excavations, generally at ground level are never leveled and refilled. With regard to the prefabricated elements from concrete, their main drawback is the high manufacturing cost; at the same time their large content of cement is another cause for environmental damage, since the raw material for the elaboration of cement is extracted from quarries. DE 2811910 A1 discloses a dry mortar mixture used as lining in mines. It is an object of the present invention to overcome the predescribed drawbacks. This object is solved by the features of claims 1 and 6. Preferred embodiments are disclosed in the dependent claims. The process of manufacturing prefabricated mortar, object of the present invention, has been devised to overcome these drawbacks with which numerous prefabricated parts may be formed that can present outer surfaces being somewhat rough or granulated, or smooth depending on how they are programmed, the material being made from a mixture of inorganic solids, comprising flying ashes and slags obtained from coal, mixed with a small amount of portland cement and another small part of water, being possible to get a fast drying by the addition of a hardening accelerator. In the case of certain prefabricated parts that need thermal treatment, a small amount of sodium silicate is added to the above described mixture as a substitute of portland cement, so that it will contribute to obtaining a perfect homogenization of all the components. Optionally, expanded clay and common sand may also be integrated in the formula. The disclosed invention presents numerous advantages, from which some of the most relevant ones are cited. It is particularly to be highlighted, the fact that up to 95 % of the material employed is recycled material obtained from flying ashes and slags of the coal that is consumed in power stations for the production of electricity. This recycling of the inorganic material that comes from the coal will reduce or prevent the formation of large ponds where the material is deposited and that are so harmful for the environment. Another essential advantage is derived from the costs, since the addition of cement is reduced to a minimum, while the ashes and slag can even be obtained at no cost, as the power stations currently spend significant sums of money for disposing of the aforementioned inorganic solids. Another economic advantage comes from the fact that some parts, such as for instance, bricks, do not need to be baked, and can be used 48 hours after being manufactured. Another advantage achieved is that of the formation of a high resistance and light weight concrete that can be manipulated either by manual procedures or by machines, concrete mixers and so on. Finally, as further advantage it is mentioned that the structure, based on inorganic solids, provides better technical features to the prefabricated parts, as while they are of a lighter weight, at the same time they provide a resistance which is higher than the ones made of clay or of concrete. For a better understanding of the object of this invention, a preferred practical embodiment of the same is represented in the accompanying drawings in which: Figure -1- shows a general schematic diagram of the process herein presented, Figure -2- shows an optional schematic diagram of the process herein presented, The process of manufacturing mortar for construction herein disclosed, begins, as it may be seen from the referenced figures, starting from inorganic solids (1), from which flying ashes (2) and slags (3) are derived, said slags (3) being ground to a predetermined calibration (4), so that afterwards,. by selection they turn into usable slag (5); on the other hand, the flying ashes (2) are also selected so that they become usable flying ashes (6). Depending upon the kind of prefabricated parts that are programmed, the mortar (7) can be made from flying ashes (6) and slags (5) of different granular sizes, with the addition of a small amount of portland cement (8) and the corresponding water (9). If the parts to be formed or moulded require thermal treatment, a small amount of sodium silicate (10) is then added to the mortar as a substitute to the portland cement. Once the mortar (7) is obteined, it goes either to moulds (11) where the parts (12) are formed through vibrations or to presses (13) where the preset parts (14) are obtained by extrusion. Another optional process for manufacturing mortar for construction herein disclosed, as can be seen in figure -2-, is that of, starting also from the usable slags (5), the usable flying ashes (6), a small part of sodium silicates (15), and water (16), and through a proper homogenization obtaining a pre-mortar (17) that is transformed in granules of different calibers (18), which are then thermally treated for hardening in the corresponding oven (19), from which hardened granules (20) are taken out. The optional mortar (21), comprises the previously described granules (20), to which usable slags (5), flying ashes (6), common sand (22), water (16), portland cement (8) and hardening accelerator additive (23) are added. Optionally, for the formation of cellular concrete with insulating effects, a gas generating additive (24) of the kind commonly used in the field, will be added to the previously described mixture. Once the mortar (21) is homogenized, it is directed either to a bulk supply (25) or towards the moulds (26) that provide the finished parts. Sulphate-resistant or sea water-resistant cements may be used when the composition of the raw material or the final use of either the mortar or the elements made therewith so require. It is also possible to use white portland cement, when it is required to give certain whiteness to the finishing of the elements. PERCENTAGE COMPOSITIONS MORTAR WITHOUT THERMAL TREATMENT Element Percentage Average Ground slag Between 70 and 90% 80% Flying ashes Between 5 and 20% 12.5% portland cement Between 4.5 and 9.5% 7% Hardening accelerator Between 0.2 and 0.8% 0:5% Optionally, the hardening accelerator may be eliminated and the parts may be left in an environmental drying process. MORTAR WITH THERMAL TREATMENT Element Percentage Average Ground slag Between 15 and 30% 22.5% Flying ashes Between 65 and 80% 72.5% Sodium silicate Between 2 and 8% 5% HARDENED GRANULE (12) Element Percentage Average Usable slag Between 15 and 30% 22.5% Flying ashes Between 65 and 80% 72.5% Sodium silicate Between 2 and 8% 5% MORTAR (21) WITH HARDENED GRANULE (20) Element Percentage Average Usable slag Between 20 and 39.64% 29.83% Flying ashes Between 32 and 76.8% 54.4% portland cement Between 5 and 11.84% 8.42% Sodium silicate Between 1 and 6% 3.5% Common sand Between 1 and 6% 3.5% Additives Between 0 and 0.7% 0.35% Optionally, formulas with the following percentage compositions may also be used: Element Percentage Average Slag Between 50 and 90% 70% Flying ashes Between 0 and 20% 10% portland cement Between 4 and 25% 14.5% Common sand Between 0 and 10% 5% Additives Between 0.2 and 0.8% 0.5% Element Percentage Average Slag Between 10 and 30% 20% Flying ashes Between 0 and 10% 5% Expanded clay Between 45 and 70% 57.5% portland cement Between 4 and 20% 12% Common sand Between 0 and 10% 5% Additives Between 0.2 and 0.8% 0.5% The amount of water to be added for each formula will be according to the needs of the machine that homogenizes the plaster and the predetermined texture of the mortar. The mortar in dry state, that is, before being formed with water, is suitable for packaging, and may be transported with the only precaution that it may not get wet, as is the case for cements. Among the numerous parts that can be formed with the invention herein disclosed, only the following is mentioned as examples: single and double bricks, hollow bricks with lattice, lattices, tiles -both flat and curved-, being also possible the moulding of parts such as blocks, jack arches, beams, paving stones, floor tiles, kerbs and any kind of mouldable part. Having sufficiently described the nature of the present invention, and a way of putting it into practice, it is only to be added that it is possible to vary slightly the percent ratios, provided that said alterations do not vary substantially the nature of the invention that is claimed as follows:

Claims: Process of manufacturing prefabricated parts from mortar, wherein inorganic solids obtained from the combustion of coal are treated such that the flying ashes are selected according to their proper caliber, the slags are ground, so that they also reach a predetermined caliber so as to be mixed according to the parts to be manufactured and in an adequate proportion, with the aforementioned flying ashes and with portland cement or sodium silicate, for the cases where the parts are to be subjected to thermal treatment, and water, further comprising a step where the mortar goes to moulds where the prefabricated parts are formed through vibration, or an alternative step where the mortar goes to presses where the prefabricated parts are obtained by extrusion. Process of manufacturing prefabricated parts from mortar according to claim 1, characterized in that the proportions of the compound for the mortar without thermal treatment comprise: ground slag between 70 and 90 percent, average 80 percent; flying ashes between 5 and 20 percent, average 12.5 percent; Portland cement between 4.5 and 9 percent, average 7 percent. Process of manufacturing prefabricated parts from mortar according to claim 1, characterized in that the compound for the mortar without thermal treatment comprises: hardening accelerator between 0.2 and 0.8 percent, average 0.5 percent. Process of manufacturing prefabricated parts from mortar according to claim 1, characterized in that the proportions of the compound for the mortar with thermal treatment comprise: Ground slag between 15 and 30 percent, averaged 22.5 percent; Flying ashes between 65 and 80 percent, average 72.5 percent; Sodium silicate between 2 and 8 percent, average 5 percent. Process of manufacturing prefabricated parts from mortar according to one of the previous claims, characterized in that common sand and/or expanded clay are added to the mixture. Process of manufacturing prefabricated parts from mortar, wherein a pre-mortar (17) is obtained through a proper homogenization of usable slags (5) which are ground so that they also reach a predetermined caliber sodium silicates (15), and water (16) and optional usable flying ashes (6) which are selected according to their proper caliber, the pre-mortar being transformed in granules of different calibers (18), which are then thermally treated for hardening in an oven (19), from which hardened granules (20) are taken out, further comprising steps where said usable slags (5), water (16), portland cement (8), and hardening accelerator additive (23) and optional flying ashes (6), common sand (22), are added to the granules (20), thereby obtaining mortar (21), comprising a step where the mortar goes to moulds where the prefabricated parts are formed through vibration, or an alternative step where the mortar goes to presses where the prefabricated parts are obtained by extrusion. Process of manufacturing prefabricated parts from mortar according to claim 6, characterized in that the granules comprise: Usable slag Between 15 and 30 % Average 22.5 %; Flying ashes Between 65 and 80 %, Average 72.5 %; Sodium silicate Between 2 and 8 %, Average 5 %. Process of manufacturing prefabricated parts from mortar according to Claim 6, characterized in that the mortar (21) is made of the pre-mortar (17) in hardened granules with the addition of usable slags, flying ashes, portland cement, sodium silicate and additives, said mortar thus being formed of the following percentage composition : Usable slag Between 20 and 39.64 % Average 29.83 %; Flying ashes Between 32 and 76.8 %, Average 54.4 %; Portland cement Between 5 and 11.84 %, Average 8.42%; Sodium silicate Between 1 and 6 %, Average 3.5 %; Common sand Between 1 and 6 %, Average 3.5 %; Additives Between 0 and 0.7 % Average 0.35 %. Process of manufacturing prefabricated parts from mortar according to claim 6, characterized in that it has the following percentage composition: Usable slag Between 50 and 90 % Average 70 %; Flying ashes Between 0 and 20 %, Average 10 %; Portland cement Between 4 and 25 %, Average 14.5 % Common sand Between 0 and 10 %, Average 5 %; Additives Between 0.2 and 0.8 %, Average 0.5 %. Process of manufacturing prefabricated parts from mortar according to claims 6, characterized in that it has the following percentage composition: Slag Between 10 and 30 % Average 20 %; Flying ashes Between 0 and 10 %, Average 5 %; Expanded clay Between 45 and 70 %, Average 57.5 %; Portland cement Between 4 and 20 %, Average 12 %; Common sand Between 0 and 10 %, Average 5 %; Additives Between 0.2 and 0.8 %, Average 0.5%.

Inventors: INNOVACIONES NEIRA Y GARCIA S, INNOVACIONES NEIRA Y GARCIA S.L., GARCIA GONZALEZ, MARIA CONCEPCION, NEIRA POUS, JOAN MARIA
Applicants: GARCIA GONZALEZ MARIA CONCEPCI, NEIRA POUS JOAN MARIA, GARCIA GONZALEZ, MARIA CONCEPCION, NEIRA POUS, JOAN MARIA
Application year: 1997
Main classification: C04B18
IPC codes: C04B18, C04B28