RU2455414C1 - Method to manufacture building material and method to erect motor road beds and surface structures on its basis - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: method to manufacture a building material, according to which a mixture of initial components with moisture within 10-15% is homogenised in the selected weight percentage ratio - natural soil - 48-75%, industrial waste with binding properties - 50-20% and an alkaline activator - 2-5%, weight or volume dosing of the mixture is carried out, the produced mix is compacted at the load from 3 to 10 MPa depending on chemical, mineral and grain-size compositions of initial components, the mode of storage of compacted materials and required mechanical properties. Also a method is described to build basements of motor roads and surface structures.

EFFECT: higher economic efficiency of a process, recycling of large quantities of various industrial wastes, increased strength and frost resistance of manufactured materials and objects and reduction of their prime cost.

22 cl, 4 tbl

Description

The invention relates to the field of construction and is intended, for example, for the manufacture of foundations for roads and railways, airfields, foundations of industrial and municipal landfills, sites for various purposes, dam cores, foundations of buildings and structures, as well as building materials such as non-fired bricks and blocks.

A number of objects are known that are close in essential features to the claimed invention, for example [1-7], the disadvantage of which is not full compliance with their operational requirements. In particular, from [1], a method is known for arranging roads and ground structures, including mixing soil with crushed slag and an alkaline activator, moistening with water in an amount of 8-20% by weight of dry components, laying and compacting the mixture, characterized in that, with In order to increase the strength and frost resistance of the bases, as well as to reduce their cost, dump slag of ferrous metallurgy is used as crushed slag in an amount of 20-40 wt.%, from which ferrous inclusions are preliminarily isolated.

From [3] there is also known a method of building the foundations of roads and ground structures, including mixing mineral material, slag of ferrous metallurgy and alkaline activator, laying, moistening and compaction, characterized in that, in order to protect the environment while maintaining water and frost resistance, as a mineral material use burned coal enrichment, or waste crushing limestone, or a burning molding sand of foundry, as slag - dispersed waste slag in an amount of 20-40 wt. from mineral material, and moistening is carried out with a solution of alkaline activator, which is used as a waste of coke production, formed at the stage of regeneration in vacuum of a solution of coke oven gas purification, or oil cracking waste formed at the stage of purification of exhaust gases.

From [5] there is also known a method of arranging road foundations by strengthening incoherent (sandy and sandy loamy) soils, however, a number of authors consider it unprofitable to strengthen loams and clays with ash-cement and ash-lime mixes [6].

The closest in technical essence and the achieved result analogue is the method of arranging the foundations of roads and ground structures, including mixing sand and loamy soils with mixtures of 2.5-5% cement or 6% Ca (OH) ₂ and 25% Estonian or Syzran ash [6] . The disadvantages of this method are: 1) low frost resistance of the bases using hydrated lime; 2) the use of compulsory activators of relatively large quantities of expensive building materials - cement and hydrated lime.

The solved problem of the claimed invention is the elimination of these shortcomings and the achievement of a practical and technical result with respect to a significant increase in the economic efficiency of the process, the disposal of large quantities of various industrial wastes as an effective method of protecting the environment, as well as increasing the strength and frost resistance of manufactured materials and objects and reducing their cost.

As a brief summary of the invention, it should be noted that the achieved technical result is achieved using the claimed method of manufacturing a building material, in which the mixture of the starting components at a moisture content of 10-15% is homogenized in a selectable weight percentage: natural soil - 48- 75%, industrial waste with astringent properties - 50-20% and alkaline activator - 2-5%, weigh or volume dosage of the mixture, compact the mixture with a load of 3 to 10 MPa in depending on the chemical, mineral and particle size distribution of the starting components, the storage mode of the compacted materials and the required mechanical properties.

The specified technical result is also achieved in modifications of the claimed method, in which:

⇒ high-base oil shale ash is used as industrial waste;

⇒ Dispersed slag of ferrous metallurgy (blast furnace, open-hearth furnace, converter or electric steel smelting) is used as industrial waste;

⇒ a mixture of ash and slag is used as industrial waste;

⇒ as an alkaline activator use additives solutions of sludge traps of thermal power plants operating on oil shale;

⇒ use alkaline effluents of caustic industries as an alkaline activator;

⇒ Parex is used as an alkaline activator (spent alkali of parex disorbate from oil refining plants);

⇒ use alkaline activator dust from electrostatic precipitators or spillage of cement plants;

⇒ as an alkaline activator use waste lime production (calcareous calcification);

⇒ as an alkaline activator use additives of lime or cement;

⇒ after compaction of the mixture, the hardening of the material is accelerated by autoclaving in the experimentally selected mode at a temperature of 175 ° -200 ° C and a pressure of saturated water vapor of 1-3 atm for 8-16 hours.

In addition, the specified technical result is also achieved in the method of building the foundations of roads and ground structures, according to which a calculated amount of soil (sand, sandy loam, loam, clay, loess, loesslike loam) is delivered to a pre-compacted subgrade, using a bulldozer and a grader to soil uniformly distributed over the surface of the subgrade. Industrial waste possessing astringent properties (oil shale ash, or finely divided slag of ferrous metallurgy, or a mixture of ash and slag in different proportions, or a mixture of this waste with cement or lime) is imported and distributed in the same way over loosened and distributed soil, and dry alkaline waste activators. These components are selected depending on their chemical, mineral and particle size distribution, as well as the requirements for the mechanical properties of the produced material with a mass ratio in the range of 45-88% soil, 50-10% binders and 5-2% dry activators. Next, the components are mixed in several passes of a road construction or marsh mill to obtain a homogeneous mixture. The mixture is moistened with water or a liquid alkaline activator in an amount of 5-15% (depending on the moisture content of the solid components and the pH of the activator). The moistened mixture is compacted with vibratory rollers or cam rollers, and in the absence of smooth rollers with a compacting load in the range of 5 to 10 MPa, and the base material is coated with a composition of ordinary road water-bitumen emulsion or liquid bitumen followed by asphalt coating.

The specified technical result is also achieved in the modifications of this method, in which:

⇒ high-base oil shale ash is used as industrial waste;

⇒ Dispersed slag of ferrous metallurgy (blast furnace, open-hearth furnace, converter or electric steel smelting) is used as industrial waste;

⇒ a mixture of ash and slag is used as industrial waste;

⇒ use alkaline activator dust from electrostatic precipitators or spillage of cement plants;

⇒ as an alkaline activator use waste lime production (calcareous calcification);

⇒ as an alkaline activator use additives of lime or cement;

⇒ Parex is used as an alkaline activator (spent alkali of parex disorbate from oil refining plants);

⇒ Soil delivery is replaced by loosening the top layer of the original subgrade using a road construction or marsh cutter, or harrow, or other mechanisms;

⇒ the mixing of all solid and liquid components is carried out in a stationary mixer in the same weight ratios and the finished building mix of the pavement base is taken out and evenly distributed on a pre-compacted subgrade;

the base material is coated with a composition of a conventional road water-bitumen emulsion or liquid bitumen;

⇒ The base material is coated with asphalt or concrete.

It should be noted that in the application the principle of unity of the invention is observed, since the proposed methods have the same purpose, serve the same purpose, independently achieve the same technical result, and are interconnected by a single inventive concept, characterized by the claims . At the same time, the concept of legal protection is based on the fact that the continuity and interconnectedness of the proposed objects, as well as the permissible variation in the implementation of certain essential features or their combinations, determine, among other things, the non-traditional nature of the formulations of some features. For example, the features of the operations of the proposed methods are reflected not only by their technological characteristics, but also by the composition and concentrations of the components used.

When presenting information confirming the possibility of implementing the claimed technical solution, it is advisable to describe in more detail practical examples of its implementation. When describing the examples, it is not advisable to dwell in detail on the information known from the published data. In detail, it is advisable to dwell only on the distinguishing essential features of the proposed solution. The explanatory examples given are not the only possible ones and clearly demonstrate the achievement by the given set of essential features of the required technical result.

In practice, in accordance with the proposed invention, to achieve the specified technical result, the production of new building materials such as bricks, blocks, etc. consists of the following technological operations:

1) mixing the components in the optimal percentage to achieve the required values of mechanical properties without preliminary drying of the components, but taking into account their moisture content;

2) weight or volume dosage of the working homogenized mixture;

3) compaction of the mixture on the press at a predetermined load, the value of which usually ranges from 3 to 10 MPa, depending on the chemical, mineral and particle size distribution of the starting components, the storage mode of the compacted materials and the required mechanical properties;

4) after compaction of the mixture to accelerate the set strength of the material, autoclaving is possible in the experimentally selected mode. However, this operation causes high energy costs and a significant increase in the cost of materials;

5) storage of compacted materials for a set of technological strength can be carried out for 1-3 days in various ways, depending on the material composition of the mixture. When mainly calcareous materials are used as a binder (waste from the production of lime, hydrated lime or lime), the finished materials can be stored in air under a canopy or under a plastic film. Materials with Portland cement or slag of ferrous metallurgy as binders are best stored in a humid environment or in tight packaging made of polyethylene film.

During the construction of roads and ground facilities, the achievement of the specified technical result in practice is ensured, in particular, by the fact that in a method comprising mixing soil with a binder (ash, or with slag or a mixture thereof), water moistening in an amount of 5-20% of the mass of dry components, laying and compacting the mixture, ashes of oil shale ash or dispersed slag of ferrous metallurgy (blast furnace, open-hearth furnace, converter or electric steel) in the amount of 10-40 wt.% or more, depending on the requirements, are used as ash s to mechanical parameters of the material produced.

To accelerate the chemical interaction of soil and binder and to increase the strength and frost resistance of the base, alkali drains of caustic plants or parex (spent alkali disorbate of parex from oil refinery plants) or electrostatic dust can be used as an alkaline activator to add solutions of sludge traps of thermal power plants operating on oil shale. and the sprinkling of cement plants, waste products of lime production (calcification of lime) and the like alkaline waste with high pH values. The required amount of liquid activators is determined experimentally and depends mainly on their pH and alkali ion concentration. In the absence of such highly alkaline waste, they can be replaced by 1-3% or more additives of lime or cement, which will inevitably cause a slight decrease in the economic efficiency of using this method.

In practice, the method of arranging the bases with the achievement of the specified technical result can be carried out as follows:

1) the calculated amount of soil (sand, sandy loam, loam, clay, loess, loesslike loam) is brought into the pre-compacted subgrade from the reserve. In some cases, the importation of soils can be replaced by loosening the upper layer of the subgrade using a road construction or marsh milling cutter, or harrow, or other mechanisms;

2) using a bulldozer, the soil is evenly distributed over the surface of the subgrade;

3) on top of the loosened and distributed soil, an appropriate amount of cementitious materials (oil shale ash, or finely dispersed slag, or a mixture of ash and slag in different proportions, depending on their chemical, mineral and particle size distribution, and also the requirements for mechanical properties of the produced material) with a mass ratio of 90-50% soil and 10-50% binders;

4) both components are mixed for several passes of a road construction or marsh mill to obtain a homogeneous mixture;

5) using a watering machine, a homogeneous mixture is moistened with water or a liquid alkaline activator in an amount of 5-20% (depending on the moisture content of the solid components) to bring the mixture into a workable state; humidification can also be carried out using a cutter if there is a special water tank on it;

6) the moistened homogeneous mixture is compacted with vibratory rollers or cam rollers, and in the absence of them with smooth rollers at a compaction load of up to 10 MPa (100 kg / cm ² ) or higher; in a compacted hydrated mixture, complex processes of chemical interaction of the soil and binder in an alkaline environment occur with a gradual transition of the working mixture to a stone-like state;

7) to prevent the premature drying of the working mixture (with interruption of the chemical interaction of the starting components), as well as to improve adhesion between the base and the overlying layer of asphalt concrete, it is necessary to create a coating of ordinary road water-bitumen emulsion or liquid bitumen.

Technological operations 1) -5) can be replaced by preparing a working mixture of soil-binder in a stationary mixer. For this, all components of the mixture are preliminarily imported into silos, with the help of dispensers they are fed into the mixer, and after receiving a moistened homogeneous mixture, dump trucks are transported to a compacted subgrade for operations 6) and 7). Moreover, due to the transportation of the starting components, and then the finished working mixture, the economic efficiency of the method will be significantly reduced.

The traditional water-breaking layer of sand of the highway construction should be canceled, because the new material needs to maintain constant humidity for long-term hydration reactions and chemical interaction of the mixture components.

In the present description of the invention, as examples of the practical implementation of the methods, the results of the author’s experiments with oil shale ashes of the Baltic State District Power Plant (Narva, Estonia) are presented, however, the proximity of its chemical and mineralogical compositions to the shales ashes of the Volga Region and the Leningrad Region leaves no doubt about the applicability of these results to the ashes of the aforementioned combustible mineral deposits. The hardening of various soils by the ash of oil shale of the Baltic State District Power Station takes place over a long period and significantly exceeds the requirements of the current Russian road construction standards, which leads to a significant increase in the overhaul period of roads.

Ash and ground base materials have high water and frost resistance (see Table 1), significantly exceeding the maximum regulatory requirements of Russian standards (see Table 2).

The coefficient of frost resistance of materials (Km) after 25 cycles of freezing at -25 ° C for 8 hours and thawing at + 20 ° C also for 8 hours in some cases exceeds unity (see Table 3). This phenomenon, as was established by detailed studies of the author, is explained by artificial desquamation (peeling) of the surface of vitrified ash particles by 50 thermal shocks (45-50 ° C for 1-2 seconds) and the increase in the active surface of ash hydration caused by them. Therefore, the number of neoplasms that strengthen the samples during frost resistance tests significantly exceeds the similar number in the compared samples of air-wet storage, which affects the value of the coefficient of frost resistance of materials.

Quite close results were obtained by the author during the hardening of various soils with the most common dispersed waste slag from ferrous metallurgy (see Table 4). Dispersed slag is obtained by crushing or grinding waste slag with magnetic separation of metallic iron. Screening of the fine slag fraction is also possible, but a decrease in the mechanical properties of the final materials is observed.

As can be seen from the above data, the proposed method allows to obtain a more durable and frost-resistant base (comparison of Tables 1, 3 and 4 with Table 2), as well as cheaper due to

1) the use of relatively cheap industrial waste as a binder;

2) replacement of two expensive layers of natural materials - the underlying layer of sand and gravel-gravel layer - with one reinforced soil layer;

3) reduction of transportation costs for the delivery of sand and gravel and gravel materials from remote quarries when replacing them with local soils.

However, the greatest effect of the widespread use of the proposed invention at an industrial level is achieved in the field of environmental protection due to the disposal of large quantities of highly alkaline waste (ash and slag) and activators of their chemical interaction with local soils.

In addition, it is possible to significantly reduce the development of quarries of traditional building materials - crushed stone, sand, gravel, etc., which irreversibly violates the natural natural bonds of the upper layer of the lithosphere.

Thus, the set of operations of the claimed methods indicated in the claims are interconnected with the formation of a stable set of essential features necessary and sufficient to obtain the required technical result. The achieved technical result, as shown by the data of experiments and the described examples, can be realized only by an interconnected set of all the essential features of the claimed objects reflected in the claims for any parameter values covered by the claimed claims and satisfying the declared features. The claimed significant distinguishing features were obtained on the basis of creative processing of the results of studies, analysis and synthesis of them and known from published data sources, interconnected by the conditions for achieving the technical result indicated in the application, as well as using inventive intuition. The above convincingly proves the compliance of the claimed methods with the legally applicable conditions established by law.

Table 1 Change in tensile strength during uniaxial compression and fracture of samples of a hydrated soil mixture with 30% additive of oil shale ash from the Baltic State District Power Plant Options Soil type Hardening terms, days one 7 fourteen 28 90 180 360 R compression, MPa M.S. 1,2 6.9 8.7 12,2 19.6 18.3 19.7 P.S. 1,1 8.8 9.1 14.9 30.3 27.4 31.1 Loess 6.2 8.4 8.4 11.0 19,4 27.1 22.6 σ gap, MPa M.S. 0.4 1,6 1.9 2.2 4.8 4.2 4.8 P.S. 0.3 2.0 2.6 3.4 3.8 4.6 5.5 Loess 0.3 1,2 1.8 2.2 2,8 3.8 4,5 Note: M.S. - moraine loam, P.S. - cover loam.

table 2 Basic requirements of SN 25-74 to the mechanical properties of reinforced road bases Material properties base Road Categories I II III Strength of uniaxial compression of water-saturated samples, MPa 6-4 4-2 2-1 Coefficient of frost resistance after 25 cycles 0.75 0.70 0.65

Table 3 Water resistance and frost resistance of 90-day-old samples of a hydrated soil mixture with 30% addition of oil shale ash from electrostatic precipitators of the Baltic State District Power Plant Soil type Water resistance after 24 hours of saturation Frost resistance, after 25 cycles R compression, MPa Water resistance coefficient Kv R compression, MPa Coefficient of frost resistance Km Wet Air Storage Water saturated M.S. 12,2 9.5 0.78 11.1 1.17 P.S. 14.9 11.0 0.74 11.7 1.06 Loess 11.0 9.0 0.82 7.4 0.82 Note: M.S. - moraine loam, P.S. - cover loam.

Table 4 Change in strength under uniaxial compression, water and frost resistance of various soils by the most common slag of ferrous metallurgy Material Compositions Strength (MPa) after (days) Water and Frost Resistance Soils Toxins 28 90 360 Rв Sq Rm Km Light clay Domain 2.9 2.6 3.6 2.5 0.96 2.08 0.84 Heavy loam 2.5 3,1 6.0 2.9 0.96 2,30 0.79 Medium sand Open-hearth 1,5 3.0 5,6 3.4 1,04 4.08 1.16 Light clay 1,2 1.9 7.0 1.7 0.93 1,50 0.86 Loam loesslike. Electro Steelmaking 4.8 9.2 7.8 9.6 1.16 7.96 0.83 5.8 11.9 14,4 13.6 1.13 11.0 0.81 Heavy loam Converter 2.1 3,7 8.6 4.3 1.14 3.32 0.78 Where: Rв and Rм - strength of water-saturated samples after 25 cycles of freezing and thawing (-25 ° С and + 20 ° C) at 90 days of age, Kv and Km are the coefficients of water and frost resistance of materials at 90 days of age.

Literature

1. Mymrin V.A. RF patent No. 2028408, IPC E01C 7/36, priority 18.07.1990

2. Mymrin V.A. Kochetkova R.G. RF patent No. 2030507, IPC E01C 7/36, priority 07.07.1992

3. Mymrin V.A. RF patent №2060315, IPC E01C 7/36, priority 28.06.1991

4. Mymrin V.A. RF patent No. 2101413, IPC E01C 7/36, priority 07.06.1996

5. Volodko V.P. The use of ashes and slag in road construction. Ukrainian Road Carrier, 1972, No. 4.

6. Sherwood P.T., Pocok R.G. Roads and road construction, v. 47, No. 554, 1969.

7. Goncharova L.V., Guryachkov I.L. and Panyukova M.P. Strengthening dispersed soils using fly ash and ways of their activation. Proceedings of SoyuzDorNII, issue 82, Moscow, 1975.

Claims (22)

1. A method of manufacturing a building material, in which a mixture of starting components at a moisture content of 10-15% is homogenized in a selectable weight percentage: natural soil - 48-75%, industrial waste with astringent properties - 50-20% and alkaline activator - 2-5%, produce a weight or volumetric dosage of the mixture, compact the resulting mixture at a load of 3 to 10 MPa, depending on the chemical, mineral and particle size distribution of the starting components, the storage mode of the compacted materials and the required mechanical FIR properties. 2. The method according to claim 1, in which highly industrial ash of oil shale is used as industrial waste. 3. The method according to claim 1, in which dispersed slag of ferrous metallurgy is used as industrial waste (blast furnace, open-hearth, converter or electric steel). 4. The method according to claim 1, in which a mixture of ash and slag is used as industrial waste. 5. The method according to claim 1, in which, as an alkaline activator, additives are used for solutions of sludge traps of thermal power plants operating on oil shale. 6. The method according to claim 1, in which alkaline effluents of caustic industries are used as alkaline activator. 7. The method according to claim 1, in which parex is used as an alkaline activator (spent alkali of parex disorbate of petroorgsintez plants). 8. The method according to claim 1, in which the dust of electrostatic precipitators or sprinkling of cement plants is used as an alkaline activator. 9. The method according to claim 1, in which the waste of lime production (calcareous calcification) is used as an alkaline activator. 10. The method according to claim 1, in which as an alkaline activator use additives of lime or cement. 11. The method according to claim 1, in which, after compaction of the mixture, the hardening of the material is accelerated by autoclaving in the experimentally selected mode at a temperature of 175-200 ° C and a pressure of saturated steam of 1-3 atm. within 8-16 hours 12. The method of building the foundations of roads and ground facilities, according to which the calculated amount of soil (sand, sandy loam, loam, clay, loess, loesslike loam) is delivered to a pre-compacted subgrade, using a bulldozer and a grader, the soil is evenly distributed over the subgrade surface, on top loosened and distributed soil is imported and distributed in the same way industrial waste with binders (oil shale ash, or finely dispersed slag of ferrous metallurgy, or cm si ash and slag in different proportions, or mixtures of these wastes with cement or lime) and dry alkaline activators, which are selected depending on their chemical, mineral and particle size distribution, as well as the requirements for the mechanical properties of the material being produced at a mass ratio within 45- 88% of the soil, 50-10% of binders and 5-2% of dry activators, the components are mixed in several passes of a road construction or swamp mill to obtain a homogeneous mixture, the mixture is moistened with water or a liquid alkaline activator in quantities e 5-15% (depending on the moisture content of the solid components and the pH of the activator), the moistened mixture is compacted with vibratory rollers or cam rollers, and in the absence of them with smooth rollers at a seal load of 5 to 10 MPa and cover the base material with a composition of ordinary road-water bitumen emulsion or liquid bitumen followed by asphalt coating. 13. The method according to p. 12, in which highly industrial ash of oil shale is used as industrial waste. 14. The method according to item 12, in which dispersed slag of ferrous metallurgy is used as industrial waste (blast furnace, open-hearth, converter or electric steel). 15. The method according to item 12, in which as an industrial waste use a mixture of ash and slag. 16. The method according to item 12, in which the dust of electrostatic precipitators or sprinkling of cement plants is used as an alkaline activator. 17. The method according to item 12, in which as the alkaline activator use a waste of lime production (calcification of lime). 18. The method of claim 12, wherein lime or cement additives are used as the alkaline activator. 19. The method according to item 12, in which parex is used as an alkaline activator (spent alkali parex disorbate of oil refining plants). 20. The method according to item 12, in which the base material is coated directly with concrete. 21. The method according to item 12, in which the importation of soils is replaced by loosening the upper layer of the original subgrade using a road construction or marsh milling cutter, or harrow, or other mechanisms. 22. The method according to item 12, in which the mixing of all solid and liquid components is carried out in a stationary mixer in the same weight ratios and the finished building mixture of the base of the pavement is taken out and evenly distributed on a pre-compacted subgrade.