MXPA98009713A - A systematic method to produce a cementity mixture, and a mixed and a cementicity grounded with such met - Google Patents

Abstract

The invention provides cementitious mixtures, particularly to be used as binder materials for torch (spray applied concrete). The invention also provides a method for producing said mixtures systematically. The resulting torret has fast setting characteristics, as low as 5 to 10 minutes, high early compressive strength (5 to 25 MPa in two hours setting, 20 to 60 MPa in a one day setting), high permanent compressive strength and megligible contraction. High-alumina cement slags with anhydrous gypsum, lime, limestone, bentonite and other additives are used in the mixtures. These mixtures are especially suitable for use in torrette engineering. The methods for using the improved torrette are similar to the methods of using Portland cement with a significantly reduced rebound

Description

A SYSTEMATIC METHOD TO PRODUCE A CEMENTIAL MIXTURE, AND A MIXTURE AND A CEMENTITIOUS CREAM PRODUCED WITH SAID METHOD • BACKGROUND OF INVENTION 1. Field of the Invention The present invention relates to cement and concrete products in general and, in particular, to methods to produce cementitious compositions that include, as • ingredients: cement, plaster, sand and / or gravel and water. More particularly, cementitious compositions have one or more of a variety of additives that produce final compositions, adjusted in terms of setting range, resistance, contraction, etc., to meet established specifications. More particularly still, the present method and the product are suitable for application in the mining industry and the like and provide a fast set, high strength and a application by throwing or spraying (torcrete) of low ratio. (For reasons of economy in the nomenclature used in the present description, the thrown cement (torcrete) of the present invention will be called "Suncrete", which is a registered trademark of the assignee of the present invention). 2. Background of the Invention In the Civil Engineering Dictionary (Penguin, 1991) the article on "Shoterete" (Torcreto) reads as follows: "Gunite with aggregates greater than 10mm, a late 1950s development of the NATM (New Austrian Tunneling Method) to coat tunnels in two stages, using torrete (shoteret) immediately after of blasting with explosives, with an aggregate of up to 30mm and a mixture of steel to reinforce the torret, and sometimes also roof bolts, but some users have replaced these with steel fiber reinforcements. time as short as 15 minutes providing a safe roof for workers in large excavations, such as the Milan-Rome highway, 24m wide built in the 60s. " The "Gunite", which differs from the torret, is defined because it has smaller aggregates of 10mm while the torretto uses aggregates larger than 10mm. In this specification, however, the term "torcrete" will be used to include all classes of this product, regardless of the size of aggregates. Several North American Patents are directed 56/60 al torcreto, concrete compositions applied by launched and the like. U.S. Patent No. 4,804,563 issued February 14, 1989, in the name of Hillemeier et al., Describes a throwable concrete composition that is sprayed at pneumatic pressure and whose setting time is accelerated by incorporation into the injection air. , of amorphous silica powder having a specific surface area of at least 25 m / g. U.S. Patent No. 4,931,098 issued June 5, 1990, in the name of Danielssen et al., Discloses a method for adding silica vapor to a mixture of dry torrette, in which silica vapor is added together with water supplied to the dry mixture in the nozzle of the launching cannon. U.S. Patent No. 5,076,852 issued December 31, 1991 in the name of Bloys et al., Discloses a composition for cementing a well that penetrates underground formations containing aqueous drilling fluid and at least one cement retarder, characterized by a larger proportion of the drilling fluid from the well as it was drilled; Water; a smaller proportion of dry cementitious material; a small amount of a dispersant that does not produce the satisfactory setting of the cement within 56/60 an acceptable range; and an accelerator selected from the group consisting of acetic acid; the first esters of four carbons thereof, acetamide and monoethanolamine. The first 4-carbon esters are methyl, ethyl, propyl (normal and isopropyl) and butyl, (normal isobutyl and tertiary butyl). U.S. Patent No. 5,149,370 issued September 22, 1992 in the name of Olaussen et al., discloses cement compositions having improved properties such as greater stability, reduced tendency to sedimentation, better fluid loss properties and the like, and a method for using such cement compositions. The cement compositions comprise water, hydraulic cement and an aqueous colloidal suspension of silicon acid in which the colloidal particles of silicic acid have a specific surface area of between about 50 m / g and about 1000 m / g. U.S. Patent No. 5,158,613 issued October 27, 1992 to the name Sargeant et al. Discloses a high density hydraulic cement slurry, especially for the cementing of oil / gas wells. The slurry contains 30-45% by weight of microsilica based on the weight of the cement and water until a specific gravity of 1 9-3.5 g / cm is achieved. If desired, a dispersant, a retarder and a weighting agent may be added. The microsilica acts as an agent that prevents the loss of fluid. The addition of microsilica prevents the retrogression of resistance to temperatures above 120 ° C and acts as a mechanical stabilizer for the slurries. A method for the production of the cement slurry is also described. U.S. Patent No. 5,234,497 issued August 10, 1933, in the name of Crocker, describes a fast-setting cementitious composition which, when hydrated, forms a slurry of slurry is useful for sealing losses in the walls of cement pipes. The cementitious composition comprises a dry blend of a hydraulic cement component having a first constituent of Portland cement and a second constituent of calcium aluminate, an aggregate component and a lime component. After hydration with 23% by weight of water, the resulting slurry has an initial Vicat setting time of the order of 1-5 minutes and a final Vicat setting time of no more than 6 minutes. The cement component contains the first and second cement constituents in weight ratios within the order of 3: 2-2: 3. The lime component is present in an amount of the order 1-4% by weight. When a water loss is repaired, a slurry is formed with water and the dry cementitious composition. Sufficient force is applied on the paste to hold it against the repair site while the cement is allowed to set to provide enough strength to overcome the hydraulic gradient and stop the leakage of water. U.S. Patent No. 5,273,579 issued December 28, 1993, in the name of Tanaka et al., Discloses a fast setting composition capable of developing satisfactory strength irrespective of the fluctuation of the ingredients of a metallurgical slag, excellent resistance to low temperature, which is inexpensive. The composition contains a cement ingredient comprising Portland cement and / or mixed cement; 2 to 50% by weight of a fast-setting agent prepared by adding 3 to 20% by weight of an alkaline carbonate to a mixture comprising 40 to 95% by weight of a finely divided metallurgical slag and 5 to 60% by weight of a type II anhydrous gypsum, based on the cement ingredient, and 0.1 to 5% by weight of a coagulation control agent comprising a coagulation retarder of the type of organic acid and alkali sulfate and / or calcium salt, Don based on the total weight of the cement ingredient and the fast-setting ingredient. U.S. Patent No. 5,389,144 issued February 14, 1995 to Burge et al., Discloses mixtures for cast concrete or mortar containing or consisting of silicic acid and which are used in the processing of concrete or mortar launched in accordance with dry or wet method. Such mixtures result in a clear reduction in dust formation and shrinkage. The addition of the aforementioned mixtures preferably takes place during the spraying, for example, in the nozzle of the launching cannon. U.S. Patent No. 5,413,819 issued May 9, 1995, establishes that the storage and processing times of released concrete can be significantly extended by the addition of a retarder, a chemical compound capable of chelating with chemical ions. Preferred retarders are phosphonic acid derivatives having at least one amino group and / or a hydroxyl group. The retarder can be used for both wet and dry cast concrete. The usual accelerators can be used for activation without adversely affecting the resistance. U.S. Patent No. 5,401,538 issued May 28, 1995 in the name of Parito describes flame retardant release compositions for structural members such as steel columns, and also a method for applying multiple layers of said compositions. The compositions comprise a Portland cement based material, stucco, a high density aggregate and an accelerator. The compositions eliminate the long setting times typical of Portland cement-based materials and improve their adhesion. The product is produced by dry mixing a mixture of Portland cement, a high density aggregate, stucco (sulfate and calcium hemi-hydrate) and optionally a stucco setting retarder and an aggregate of polystyrene filaments. When adding water, throwable slurries are formed, which can be pumped to the point of application. An accelerator is added in close proximity to the injection point. The grouts adhere to the structural member in an aqueous state and, after setting, provide excellent protection against fire and heat. Due to the relatively fast setting time of the slurry when it is thrown, multiple layers can be applied within the same working day. Chinese Patent Application No. ZL90103141.0 filed in 1990 describes a cementitious slurry of high water content (90% water by volume) for the filling, in mines using cement slag, as slag of sulfo-fluo cement -aluminate and other aluminate cement slags. However, such slurry is not suitable for use in applications of torret or similar. The 56/60 Main minerals in these types of cement are: Sulfo-aluminate cement: 3CaO.3A1203. CaSo4-ß-2CaO. Si02; sulfo-ferrite cement - 3CaO.3Al203.CaSo4-ß-2CaO. Si02; aluminate: and CaO. A1203. Fe203; sulfo-fluo-aluminate cement: 3CaO.3Al203.CaSo4-ß-2CaO. Si02; and HCa0.7Al203.CaF2; high content cement CaI, Al203.y 12CaO.7A1203; of alumina SUMMARY OF THE INVENTION The present invention has for its object to provide an appropriate cementitious mixture, to be applied, in particular, as a torrette in mining, but in general also in other constructive applications. The invention also provides a method for producing said compositions in a systematic manner. In conventional torrette technology, a large proportion (greater than 70%) of the material that binds to the cement consists of calcined clinkers which are high cost materials due to calcination. The setting time and the malleability are adjusted by high cost additives. In addition to the economic disadvantages, the use of additives produces some loss of strength and stability. The present invention allows increasing the 56/60 uncalcined ingredients, such as gypsum anhydrite in the binder material. The setting time can be adjusted by means of the proportions ratio of slag of calcined cement, gypsum and lime. The result is a torret improved in cost, time of setting, resistance and ease of adaptation to the required specifications. Long-term stability is also improved. One problem in the manufacture of torchite is the equilibrium between setting time and long-term resistance. In order to reduce the setting time, an accelerator such as a material containing NaCO is used. However, this significantly decreases long-term resistance. In the present invention, additives are produced by mixing accelerators (such as NaCO containing materials) together with retarders (such as sugars and molasses). The improved torrete has a shorter setting time and greater resistance and long-term stability. Another aspect of the present invention is the advantageous use of lime, which in conventional torrette technology is undesirable because it reduces strength and stability and is generally maintained below 0.5%. As will be seen in "Test Example 1" below, lime (which is inexpensive) is advantageously used. Without the use of lime and using 85% to 95% of 56/60 slag of sulfo-aluminate cement, 5% to 15% of gypsum and mixing with sand and water at 22 ° C with a ratio of 1: 2.5 (sand): 0.5 (water), time The resulting setting time is 45 to 120.minutes, and the setting resistance is from 1 to 2 hours practically nil, while the setting strength of 4 hours is 0.5 to 2 MPa. Therefore, in a broad aspect of the invention, a mixture of torchite comprising up to 30% by weight of lime is provided before adding sand, gravel or water. In another aspect of the present invention, it provides torchite with a wider range of the allowable water to cementitious mixture ratio of 0.35 to 1.0 as opposed to prior art, in which the ratio is 0.35 to 0.6. As an example, a ratio of cementitious mixture according to the present invention to sand to water of 1: 2.5: (0.6 to 1.0) would result in a torrette with a setting time of 1 to 5 minutes, a setting strength at the end of 2 hours from 9 to 16 MPa, and a setting resistance after 6 hours from 12 to 30 MPa. Some of the cementitious mixtures of the present invention are characterized by fast setting times, high compressive strength within hours of curing time and low retraction or shrinkage, while having a low cost. In addition, the mixtures of 56/60 present invention are also suitable for use in winter construction, marine port construction, irrigation engineering, road construction, flood dams, containment of industrial waste and other similar applications. Accordingly, the present invention provides a systematic method for producing an intermediate cementitious mixture, comprising: (a) mixing together at least one ingredient of a first basic group of ingredients comprising: all sulfo-aluminate cement slags and others high alumina cement slag, at least one ingredient of a second basic group of ingredients comprising: gypsum, anhydrite, hemi-hydrated gypsum, and at least one ingredient of a third basic group of ingredients comprising lime and hydrated lime. (b) adding to the mixture of (a) in a ratio not exceeding 20% by weight, at least one additive ingredient of a first group of additive ingredients comprising: tartaric acid and its salts, boric acid and its salts, carbonates, lignosulfonates, sugars, molasses, citric acid and its salts, and sulfonates, and / or at least one additive ingredient of a second group of additive ingredients comprising: all 6/60 alkalies, strong base salts strong acid, strong base salts-weak acid, lithium salts, lithium compounds, fluoride salts, chloride salts, and sulfonates, and (c) all mixtures and aggregates of ( a) and (b) are made in any order in predetermined proportions to give said intermediate cementitious mixture. According to the present invention, the cementitious mixture comprises: (a) a mixture of at least one ingredient of a first basic group of ingredients comprising all the sulfo-aluminate cement slag and other cement slag having a high content of alumina, at least one ingredient of a second basic group of ingredients comprising; gypsum, anhydrite, hemi-hydrated gypsum, and at least one ingredient of a third basic group of ingredients comprising lime and hydrated lime, and (b) in a ratio not to exceed 20% by weight of the mixture of (a) by at least one additive ingredient of a first group of additive ingredients comprising: tartaric acid and its salts, boric acid and its salts, carbonates, ligno-sulfates, sugars, molasses, citric acid and its salts and sulfonates, and / or less a 6/60 additive ingredient of a second group of additive ingredients comprising: all alkalis, strong base salts - strong acid salts, strong base salts - weak acid, lithium salts, lithium compounds, fluoride salts, salts of chloride, and sulfonates.

BRIEF DESCRIPTION OF THE DRAWINGS The preferred embodiments of the present invention will now be descriptive in detail with reference to the accompanying drawings, in which: Figure 1 is a diagram illustrating the systematic method of the present invention for producing torrette; Figure 2 is a diagram explaining the composition of a first intermediate mixture to make a torrette according to the present invention; Figure 3 is a diagram explaining the composition of a second intermediate mixture to make a torrette according to the present invention; Figure 4 is a diagram explaining how the intermediate mixtures of Figures 2 and 3 are combined with sand, gravel and water to produce in situ torcrete; Figure 5 is an alternative embodiment that explains how another intermediate mixture is obtained to make torrette according to the present invention; 56/60 Figure 6 is yet another alternative embodiment that explains how another intermediate mixture for making torrette is obtained according to the present invention; Figure 7 is still another alternative embodiment explaining how another intermediate mixture for making a torret is obtained according to the present invention; Figure 8 is yet another alternative embodiment that explains how another intermediate mixture for making a torret is obtained according to the present invention; Figure 9 is yet another alternative embodiment that explains how another intermediate mixture for making a torret is obtained according to the present invention: Figure 10 is an alternative embodiment for making the final mixture (before adding water) according to the present invention; Figure 11 is another alternative embodiment for making the final mixture (before adding water) according to the present invention; Figure 12 is an alternative embodiment for producing in situ torcrete with an intermediate mixture, sand, gravel and water; Figure 13 is yet another alternative embodiment for producing in situ torrette with an intermediate mixture, sand, gravel and water; Figure 14 illustrates productions of torrette in 56/60 situ with the final mixture S and water.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to Figure 1 of the drawings therein, the systematic method of the present invention is explained. There are five different possible groups of starting ingredients; they comprise: - The basic group of ingredients "Xb" comprises the slag class of aluminate cement, such as sulfo-aluminate cement slag, sulfo-ferrite-aluminate cement slag, slag of sulfo-fluo-aluminate cement; all forms of cement slag with high alumina content; The basic group of ingredients "Yb" comprises two sub-groups "Ybl" and "Yb2" as follows: Ybl: gypsum, anhydrite, hemi-hydrated gypsum; and Yb2: hydrated lime and lime. The group of additive ingredients "Ua" comprises tartaric acid and its salts, boric acid and its salts, carbonates, lignosulfates, sugars, molasses, citric acid and its salts, sulfonates. The group of additive ingredients "Va" includes all alkalis, strong base-strong acid salts, strong base-weak acid salts, lithium salts, lithium compounds, fluoride salts, salts of 6/60 chloride, sulfonates; and The additional group of "Z" ingredients comprises any member of groups Xb and Yb, bentonite, ash, silica dust, common cement, limestone, gypsum, lime. This group of ingredients is mainly used to help the mixture when necessary and to improve the flow of the mixture before combining it with water to spray it as a torret in situ. Sometimes Z is used to adjust the setting time, to improve the strength and to reduce the cost of the torret during the production and application of the intermediate and final mixtures. Once the ingredients are mixed together in predetermined proportions to give, for example, a torret with certain specifications, intermediate mixtures are designated as "Ml", "M2", "M3" etc. An intermediate mixture gives a final "S" mixture after being combined with sand and / or gravel. The final mixture "S" is then combined with water at the time of release as a torret in situ. Figures 2 and 3 explain how the ingredients Xb, Yb, Ua, Va and Z are combined to give two intermediate mixtures Ml and M2 which in turn are combined as illustrated in Figure 4 to give the intermediate mixture M3 which is mixed with sand and gravel to give the final mixture S 56/60 before adding water at the moment of the release of the torret. The predominant and usual effects of the various ingredients and additives can be summarized as follows: Xb - increases long-term resistance and improves water resistance; Yb - increases the hydration regime of Xb and accelerates the formation of ettringite compounds (important for resistance and crystallization) for torrette applications. (Ua + z) - useful as dispersing agents, retarders and water reducers to adjust the setting times and improve the malleability and resistance of the torret. (Va + z) -as useful as accelerators to obtain very short setting times and develop high early strength in the torret. In the examples that follow, as well as when applying the methods and compositions of the present invention, some experimentation may be required in order to obtain results that are within narrower ranges of variability, and in order to compensate for unavoidable variations in composition. of the starting materials. The remaining figures 5 to 14 explain different routes to obtain different intermediate and final mixtures 56/60 and indicate the proportions of the intermediate and final mixtures to be combined with sand and / or gravel and water at the time of release as a torret in situ. Such different routes can offer optimal solutions (in terms of cost) depending on availability, or lack of availability of various ingredients at manufacturing sites. For example, it is evident that where sand and gravel are available at or near the site where the torret is required, they must be added in situ to obtain the final mixture S near the application site. Following are some quantitative test examples to produce the torrette.

Trial Example 1 Sulfo-aluminate cement slag (Xb) 65 to 80% Gypsum (Yb) 10 to 20% Cal (Yb) 5 to 10% Sugar (Ua) 0.2 to 0.5% Lithium (Va) 0.5 to 1.0% Mixing uniformly and grinding the ingredients together to obtain a fine powder mix of 200 mesh, then mixing a portion of this mixture with 2.5 portions of sand, 2.5 portions of gravel and 0.55 portion of water, then pouring the slurry into a mold of 100mm x 100mm x 100mm, were obtained 56/60 the following results in the laboratory: Setting time 5 to 20 minutes Resistance to compression set after one hour 5 to 10 MPa set after two hours 10 to 20 MPa set after six hours 20 to 30 MPa set after 30 to 60 days MPa set after three days 40 to 80 MPa set after twenty-eight days 50 to 90 MPa The ratio of resistance to bending to resistance to compression was 3.5 to 4.0. The ratio of resistance to cut to resistance compression was from 2 to 2.5. This example demonstrates the properties of fast setting and hardening, early high strength and good hardness of the composition of the invention, characteristics are appropriate for the engineering and applications of torrette.

Test Example 2 To obtain a torchite with binder material having a very short setting time and a very high early strength, the following composition is appropriate: 56/60 Predominant effect on torchite Sulfo-aluminate or sulfo-ferrite-aluminate cement slag (Xb) 50 to 70% (Higher resistance) Gypsum or anhydrite (Ybl) 20 to 35% (Low shrinkage and greater resistance) Lime or hydrated lime (Yb2) 5 to 20% (Accelerates setting) Sodium carbonate (Ua) 0.5 to 2% (Accelerates the setting) Hydrated lithium (Va) 0.1 to 1% (Increases strength and accelerates setting) Sodium chloride (Va) 0.5 to 2 (Reduces water requirement) Mixing and grinding these ingredients as in Test Example 1, then mixing with 1 portion of the obtained mixture, 2.5 portions of sand, 2.5 portions of gravel, and 0.6 portions of water, and pouring the slurry into a cylindrical mold with a diameter of 7.5 cm and a height of 15 cm at 22 ° C the following results were obtained: Setting time 1 to 5 minutes Resistance to compression set after one hour 5 to 10 MPa 56/60 set after two hours 10 to 20 MPa set after 25 days at 50 MPa set after three days 40 to 60 MPa Setting time 30 to 50 minutes Resistance to compression set after six hours 5 to 10 MPa set after 12 hours 25 to 40 MPa set after 35 days at 50 MPa set after three days 45 to 80 MPa • Test Example 3 To obtain a setting time of 30-40 minutes and an understanding resistance of 60 to 80 MPa with the following composition: Sulfo-aluminate cement slag or cement slag from 75 to 85% sulfo-ferrite-aluminate (Xb) aluminate (Xb) 75 to 85% Gypsum or anhydrite (Yb) 12 to 20% Cal or hydrated lime (Yb) 2 to 10% Sugar or citric acid (Ua) 0.1 to 0.4% Mixing and grinding these ingredients until 56/60 obtain a mixture of fine powder and then mixing with a portion of the mixture with 2 or 3 portions of sand, 2 to 3 portions of fat and 0.45 portions of water, and pouring the slurry into a cylindrical mold of 7.5 cm in diameter and 15 cm in height, the following test results were obtained. Setting time 30 to 50 minutes Compressive strength set after 6 hours at 5 to 10 MPa, hardened after 12 hours 25 to 40 MPa, hardened after 35 days at 50 MPa, after 3 days 45 to 80 MPa In order to prepare the ingredients Xb and Yb uniformly and to reduce the final cost of the product, they can be used, as basic ingredients and additives of Ml and M2, some cheaper materials such as bentonite, ash dust, Portland cement silica powder, limestone, lime, gypsum and some sludge, for example as follows: Proportions by weight (Ua + Z) (See Figure 2) Sugar or citric acid or boric acid 50 to 100 portions Sodium carbonate or sodium sulfonate 50 to 200 portions Limestone or bentonite or ash dust 5 to 200 portions 56/60 Servings by weight for (Va + Z) (See Figure 3) Sodium or alkali chloride 50 to 200 portions Hydrated lithium or lithium chloride 50 to 200 portions Bentonite or gypsum or cement or 5 to 400 portions Other compositions for intermediate mixtures, suitable for use in torchite are given below. All proportions are by weight.

Example A Sulfo-aluminate cement slag 60 to 100 portions Plaster or anhydrite 20 to 50 portions Lime or anhydrated lime 5 to 20 servings Calcium lignosulfate 0.01 to 2 portions Carbonate of sodium 0.05 to 4 portions Example B Sulfo-ferrite-aluminate aluminate cement slag 60 to 100 portions Gypsum or anhydrite 50 to 70 portions Lime or hydrated lime 10 to 30 servings Molasses 0.1 to 1.5 servings Sodium carbonate 0.5 to 3 servings Sodium chloride 0.1 to 2 servings Lithium hydrated 0.5 to 2 servings 56/60 Example C To prepare the intermediate mixture M7 (See Figure 9), the proportions by weight were: Cement slag with high alumina content 50 to 100 portions Plaster or anhydrite 20 to 70 portions Lime or hydrated lime 5 to 40 servings (Ua + Z) 0 to 4 servings (Va + Z) 0 to 4 servings N.T. The terminology used in the translation is based on the Manual of the Engineer of Hitte, volume IV, Gustavo Gili, 1980. 56/60

Claims (8)

1. CLAIMS: 1.- A systematic method to produce an intermediate cementitious mixture, characterized in that - comprises: (a) mixing together at least one ingredient of a first basic group of ingredients comprising: all sulfo-aluminate cement slag and other high alumina cement slag, at least one one-second ingredient basic group of ingredients comprising: gypsum, anhydrite, hemi-hydrated gypsum, and at least one ingredient of a third basic group of ingredients comprising lime and hydrated lime; (b) adding to the mixture of (a) in a ratio not exceeding 20% by weight, at least one additive ingredient of a first group of additive ingredients comprising: tartaric acid and its salts, boric acid and its salts, carbonates, lignosulfonates, sugars, molasses, citric acid and its salts, and sulfonates, and / or at least one additive ingredient of a second group of additive ingredients comprising: all alkalis, strong base salts strong acid, base salts strong-weak acid, lithium salts, lithium compounds, fluoride salts, chloride salts, and sulfonates, and 56/60 (c) all mixtures and aggregates of (a) and (b) are made in any order in predetermined proportions to give said intermediate cementitious mixture.
2. 2. A cementitious mixture made according to the method of claim 1, characterized in that it comprises at least one material of the group consisting of sand and gravel in predetermined portions.
3. 3. A cementitious mixture according to claim 2, for making in situ torcrete by adding water in a predetermined proportion comprised between 10% and 80% by weight.
4. 4. A cementitious mixture characterized in that it comprises: (a) a mixture of at least one ingredient of a first basic group of ingredients comprising all the sulfo-aluminate cement slag and other cement slag with high alumina content, at least one ingredient of a second basic group of ingredients comprising; gypsum, anhydrite, hemi-hydrated gypsum, and at least one ingredient of a third basic group of ingredients comprising lime and hydrated lime, and (b) in a ratio not to exceed 20% by weight of the mixture of (a) by at least one additive ingredient of a first 6/60 group of additive ingredients comprising: tartaric acid and its salts, boric acid and its salts, carbonates, ligno-sulfates, sugars, molasses, citric acid and its salts and sulfonates, and / or at least one additive ingredient of a second group of additive ingredients comprising: all alkalis, strong base salts-strong acid salts, strong base-weak acid salts, lithium salts, lithium compounds, fluoride salts, chloride salts, and sulfonates.
5. 5. A cementitious mixture according to claim 4, characterized in that it comprises at least one material of the group comprising sand and gravel in predetermined proportions.
6. 6. A cementitious mixture according to claim 5, characterized in that it comprises a ratio of water to cementitious mixture comprised between 0.4 and 0.8 by weight to be used as a torchite in situ.
7. 7. A cementitious mixture to make a torret, before adding sand, gravel or water, comprising 0.5% to 30% by weight of lime and / or hydrated lime.
8. 8. A torchite slurry characterized in that it comprises a cementitious mixture according to claim 5, and 29% to 50% by weight of water, excluding the sticking of sand and gravel. 56/60