WO2022008982A1

WO2022008982A1 - Soil sealant and stabilizer and slurries and materials strength reinforcement using minerals

Info

Publication number: WO2022008982A1
Application number: PCT/IB2021/050522
Authority: WO
Inventors: Amir Hossein SHAKERI
Original assignee: Dezhab Sang Engineering Company
Priority date: 2020-07-04
Filing date: 2021-01-23
Publication date: 2022-01-13

Abstract

In many cases, it is possible that the high water to soil aggregates ratio in swamps and coastal lands, estuaries and sandy beaches in the subsoil layers requiring excavation and construction of parking lots and underground floors causes the project to be discarded or force employers to transport and replace it with suitable materials, which is very costly and time-consuming. Injection of this product causes the conversion of the same loose and non-loadable materials into durable and buildable substrates. The method of operation is that for injection into the soil and its consolidation, the first component is mixed with water and then applied by the injection device with the second component at the same time, but for mixing in soil or construction materials, they are all mixed together in one step. For cement injections, the first component is injected directly into the cement slurry and the second component.

Description

Soil sealant and stabilizer and slurries and materials strength reinforcement using minerals

Technical Field

[0001] The technical field of this invention relates to the strength reinforcing of building and road construction materials.

Background Art

[0002] The invention of nano-composite reinforcing bed soil under patent number 85514, which is registered in the Iranian Patent Office, reveals that:

[0003] The main purpose of this invention is to increase the strength parameters of the substrate soil to increase the area of land that can be used for construction projects. At the same time, by using polyester recycled fibers, in addition to reducing the cost of soil improvement, which includes transportation costs, low material costs and ease of implementation, a big step can be taken in environmental cleanup, which includes reducing pollution from the production of materials (cement and water). Soil and waste reduction (polyethylene bottles) in nature, harvest. In this design, for the first time, two new materials, which include polyester recycled fibers and nanoparticles, have been used to strengthen the bed soil for the first time. In order to investigate the increase in substrate soil strength due to the use of this nanocomposite, samples with different percentages of nanosilica and recycled polyester fibers have been fabricated and tested. Evaluation and comparison of the results of the modified bed soil with natural bed soil indicate a significant increase in compressive strength and shear strength of the modified bed soil compared to natural bed soil.

[0004] The necessary technical background for this invention is the required knowledge about different methods of bed soil improvement, familiarity with different types of soils and knowing their weaknesses and issues such as high porosity, soil dispersion and low soil bearing capacity. Familiarity with nanoparticles and their reactions with water and soil, as well as factors affecting the properties of nanomaterial are other technical areas required to present this invention. In the present invention, nano-silica has been able to act as a suitable additive to increase soil resistance parameters due to its unique properties such as the production of sticky gel which is created by mixing nano-silica with water. Also, polyester recycled fibers, which are produced from recycled polyethylene containers such as mineral water bottles, due to properties such as absorption of tensile stresses and friction and correlation between soil particles, improve the performance of nanosilica in improving soil resistance parameters. Nanosilica, when mixed with water, produces a sticky and cohesive gel that bonds between soil particles, which is stronger than the bond due to the adsorption of water on the surface layer. This gel also increases soil resistance by filling the empty space between particles and bringing soil particles closer to each other.

[0005] On the other hand, polyester recycled fibers absorb and transfer tensile stresses by creating friction between soil particles and also by their bridge-like effect, and turn the soil into a mixture with the desired tensile capacity. Simultaneous addition of polyester and nano-silica recycled fibers improves each other's performance in increasing the soil resistance parameters. This nanocomposite can be used to increase the soil strength of loose clay substrates in roads as well as to stabilize soil areas such as parking lots and rural areas. Other applications of this type of nanocomposite include the renovation of historic buildings. The application of this nanocomposite, in addition to increasing strength, reduces environmental pollution and the cost of construction projects.

[0006] The use of powdered nanosilica in this invention makes its curing time longer in the presence of water or may be impossible. On the other hand, when the powder is used, it must be mixed with soil and will be used only in surface layers.

[0007] The invention titled soil stabilization and consolidation method and compositions is published under number 2277545 in the British Patent Office. This invention is a method of soil consolidation to form a load-bearing and waterproof surface layer, which includes the steps of mechanical composition and fusion of a wet layer and loose soil of suitable depth, previously with soil preparation liquid containing A: surfactant or B : Natural or synthetic resin latex emitted in it and also a solvent is prepared with dry soil consolidation powder which contains discrete particles of the mineral substrate with fine particles with a particle size greater than 1000 microns and is completely covered with silane. This layer is coated with hydrogenated alkyl ester amide wax and then the resulting soil layer is compacted to form the desired surface level and allows the compacted and processed soil layer to dry. Soil preparation fluid is preferably a solution of ammonium alkyl chloride and natural rubber latex dissolved in isopropanol as a solvent. Soil consolidation powder is preferably P.F.A with a particle size of 20 to 0 microns, which is coated with dimethyl dichloromethane and then coated with 6% hydrogenated alkyl ester amide wax. The method and composition make it possible to carry out quick and easy road construction operations on all soils except peat, without much excavation.

[0008] The method and formula of this invention are completely different from the claimed invention. This invention relates only to surface layers and does not apply to deep layers. Also, these materials cannot be used in wetlands and wetlands. In order to implement this plan, tools and machines for excavation and road construction are needed. Execution of this method requires more time than the claimed method to get the site ready for operation.

[0009] Another difference between this invention and the claimed invention is that this design is used only in road construction and not in other cases such as stabilization of trenches or quality improvement of building materials. This plan is not used to strengthen the bed of historic buildings or structures that need to strengthen the soil under the foundation.

Technical Problem

[0010] In many cases, it is possible that the high water to soil aggregates ratio in swamps and coastal lands, estuaries and sandy beaches in the subsoil layers requiring excavation and construction of parking lots and underground floors causes the project to be discarded or force employers to transport and replace it with suitable materials, which is very costly and time-consuming. Injection of this product causes the conversion of the same loose and non-loadable materials into durable and buildable substrates.

[0011] In soil compaction by strand anchorage and nailing method, water penetration and long setting time in loose beds impose many costs on the project and using this product in the injected slurry, in addition to blocking leakage, minimizes the tension time of the strand reinforcement and greatly increases the execution speed.

[0012] On the other hand, the pavement bed is the surface of the last compacted layer of existing embankments, excavations or natural land. The pavement bed, which is considered as the pavement of the road, bears all the loads caused by the pavement structure and vehicles on it.

[0013] Pavement bed soil should have favorable conditions in terms of strength and compaction in the short and long term. For example, fine-grained soils, especially clays, absorb and swell as soon as they come in contact with water, losing much of their stability. On the other hand, compacting these soils by conventional methods is very expensive.

[0014] However, it is much more difficult to reinforce some substrates, both for road construction and for buildings, such as swamps, beaches and areas with high groundwater levels, or substrates of structures that have been washed or asymmetrically subsided. The present invention provides cost-effective reinforcement for these substrates.

Solution to Problem

[0015] This project is a two-component product that is used to increase the strength of materials such as plaster, clay, brick, etc., as well as to stabilize the soil mass or create a cut off around underground structures without causing corrosion on rebar and metal elements. Is used. The method of operation of this product is that for injection into the soil and its consolidation, the first component is mixed with water and then applied by the injection device with the second component at the same time, but for mixing in soil or construction materials, they are all mixed together in one step. For cement injections, the first component is injected directly into the cement slurry and the second component.

[0016] The constituents of this product are as follows:

[0017] Component 1 : 80 to 100% sodium silicate or a mixture thereof with a maximum of 20% potassium silicate or vice versa

[0018] Component 2: 30 to 70% ethyl acetate. Formamide 5 to 20%. Deionized water

5 to 20% [0019] The second component in a mixing ratio of 1 :7 w% of the first component is prepared and they are mixed together at the desired location.

[0020] Given the wider diffusion of materials in the bed or the reduction of implementation costs, water may also be used in the composition, in which case, depending on the water in the bed, up to 70% can be added to the main composition of water.

[0021] On the other hand, by increasing the amount of the second component, the setting speed is significantly increased so that its duration can be reduced to less than 30 seconds. Of course, it is obvious that the rate of reaction should be selected in the workshop according to the executive facilities and its necessity. If you do not pay attention to this point, before injecting the product, the reaction will take place and it will not be possible to apply and deliver it to the desired location or injection in the borehole.

[0022] Due to its unique properties such as high adhesion and rapid (controllable) hardening in the vicinity of the second component, which is created by mixing it with water, silicate gel has been able to serve as a suitable additive and injection material to increase dry soil resistance parameters. And act wet. Adding it to the cement slurry also improves the performance of the nailing and micropile systems used in the reinforcement of the bed or the stability of the trenches due to properties such as absorption of tensile stresses and friction and correlation between cement particles and reinforcement as well as cement and soil.

[0023] By mixing the two components of this product in the presence of water, a cohesive gel is produced with an adjustable setting and hardening rate. This sticky gel causes the bond between soil particles even in water-saturated environments, which is stronger than the bond due to the adsorption of water from the layers of soil. Also, this gel fills the empty space between the particles and brings the soil particles closer to each other, turning it into a hard mass and thus increasing the soil resistance to any depth that is injected or mixed.

Advantageous Effects of Invention

[0024] 1- Given the application of liquid silicate, it is possible to inject it more easily in the bed.

[0025] 2- Given the application of liquid silicate, it is possible to inject in the substrate layers.

[0026] 3- It has fast hardening and the potential to adjust the hardening speed of the bed even in waterlogged environments.

[0027] 4- It can be used in various projects such as road construction, drilling, excavation, tunnel and consolidation of pit walls.

[0028] 5 - There are no adverse effects on the environment and the roots of plants in the soil.

[0029] 6- It obviates the need for tools and machinery for excavation and road construction.

Brief Description of Drawings

[0030] Fig 1 : Illustrates the mixing formula

Description of Embodiments

[0031] Figure 1 illustrates the mixing formula of this product. The first component is composed of sodium silicate and potassium silicate and the second component is composed of ethyl acetate, formamide and deionized water. If necessary and according to the bed up to 70%, it is possible to add water to the mixture.

Industrial Applicability

[0032] This invention can be used in swampy lands, beaches and areas with high groundwater levels in order to strengthen the bed, increase soil load resistance and also create a cut -off by injection method. Injection of this product in the soil around the building prevents water from continuing to penetrate to the depth and thickness of the walls and prevents decay and destruction of old buildings and historic buildings. [0033] Injection of this product into the bedrock of the foundation of settling structures stabilizes and strengthens it and prevents the continuation of the destructive process and the possibility of its collapse.

[0034] Other applications of this product include drilling, excavation projects, tunnels and strengthening of pit walls. It is also used in pavement bed which is considered as the pavement of the road and bears all the loads caused by the pavement structure and vehicles on it.

Examples

[0035] The method of application of this product in cement slurry:

[0036] Use of this product in cement slurry required for injection around soil stability strands by nailing method or injection slurries in the body of tunnels and underground structures to fill pores and seal. Therefore, according to the volume of operation and the expected reaction speed, the first component of the product is poured into the slurry and using a one-to-two conversion in the injection nozzle, the second component is simultaneously injected by a separate pump.

[0037] After both liquids are removed from the injection package, they are mixed together in the path and begin to react. Obviously, by increasing the mixing ratio from 1.5 to 2% to 5 to 7% by weight, the reaction rate increases significantly and the cement slurry becomes a hard and impermeable mass of water, and in addition to blocking possible leakage currents, the rate Increases the adhesion of the slurry to the rebar and the soil, which accelerates the stabilization operation by accelerating the expected strength.

[0038] Ways of using it in swamps, soils and soils wet or waterlogged without sufficient fine aggregate:

[0039] If the amount of solid particles is lower than the liquid and it exceeds 270% in swamps or there is not enough fine-grain in wet or swampy soils, injection of cement slurry will increase the expected quality. In these cases, the description of the operation will be similar to the injection of cement slurry.

[0040] Method of using it in dry, wet or wet soils with sufficient fine aggregates: [0041] In these cases, only two components of the product are used and no cement particles are needed. Depending on the amount of moisture or wetness, up to 2.5 times the first component of water can be used to increase the spread of the product in the soil mass and reduce the final cost.

[0042] Consolidation and creating impermeability in building materials:

[0043] In order to increase the strength, eliminate permeability and create non absorbent and dehumidifying properties, according to the general formula and only by changing the amount of the second component in the mixing design, which only accelerates the setting time, this product can be applied and injected through drilling packers. On the surfaces with the desired materials.

[0044] Note: Considering the use of two types of silicates in production of the first component of this product, in places where the amount of sulfate or soil chemical characteristics are likely to cause corrosion damage to the metal elements of the structure or other materials, after a thorough examination, the exact ratio of the two in the product is extracted.

Claims

[Claim 1] Soil and sealant and stabilizer and slurries and materials strength enhancer comprising: a. The first component: 80 to 100% Sodium Silicate b. 0 to 20% potassium silicate c. The second component: 30 to 70% ethyl acetate. d. 5 to 20% Formamide e. 5 to 20% deionized water

[Claim 2] According to claim 1 , the second component in mixing ration of 1 to 7 w% the first component is prepared and they are mixed together in the defined location, and if water needs to be used, up to 70% can be added to the main composition and by adding the amount of the second component compared to the first component, the setting rate of the product increases.

[Claim 3] According to claims 1 and 2, in order to use this product in the slurry, the cement required for injection around the excavation site, increasing the setting speed of grout injected in soil stabilization strands by nailing method or injection grouts in tunnel bodies and underground structures are used to fill pores and seal as well as to strengthen the bedrock of foundations and according to the expected operation volume and reaction speed, the first component of the product is poured into the slurry and using a one-to-two conversion in the injection nozzle, the second component is simultaneously injected by a separate pump.

[Claim 4] According to claims 1 and 2, for use in dry, or wet soils with sufficient fie grains, only two components of the product are used and there is no need for cement particles, which depending on the amount of moisture or wetness 2.5 times the first component, water can be added.