Preparation method of curing agent suitable for soft soil area anchor cable grouting body

Abstract

The present application relates to the technical field of anchor cable grouting body, and discloses a preparation method of a solidifying agent suitable for anchor cable grouting body in soft soil areas, which comprises the following preparation steps: 1) cement and water are placed in a stirrer to be stirred and mixed to form a cement solution; 2) emulsified asphalt is added to the cement solution to be stirred and mixed to form an emulsion; 3) water reducing agent and defoaming agent are added to the emulsion respectively, and the emulsion, the water reducing agent and the defoaming agent are stirred and mixed to form a solidifying agent; the shear resistance of cement is improved by using the emulsified asphalt and cement in a complex manner; compared with the cement neat grout used to reinforce soft soil, the present application can obviously improve the mechanical properties and water resistance of the solidified soft soil, reduce the risk of engineering construction, enhance the durability of the built building (structure), reduce the possibility of uneven settlement, and solve the problems of foundation pit instability and excessive deformation in soft soil areas.

Description

Technical Field

[0001] This invention relates to the technical field of anchor cable grouting bodies, and more specifically, to a method for preparing a curing agent suitable for anchor cable grouting bodies in soft soil areas. Background Technology

[0002] The Pearl River Delta coastal area of ​​Guangdong has a large amount of soft soil, which is characterized by high natural water content, high compressibility, and low bearing capacity. It is in a soft plastic or fluid plastic state. During the construction of projects in this area, foundation pits often experience instability and excessive deformation, which can cause construction safety hazards.

[0003] Common treatment methods include grouting reinforcement, anchor bolt reinforcement, soil nailing reinforcement, and prestressed anchor cable reinforcement, in order to harden the soil and improve the safety factor of the project.

[0004] Currently, all of these reinforcement methods use cement as the reinforcement material. However, due to the low shear coefficient of cement, when encountering deep soil disturbance, the fixed ends of cement-reinforced anchor rods and anchor cables are prone to breakage, causing structural instability and increasing the safety hazards of the project. For permanent anchor cables, it is even more likely to cause uneven settlement of buildings (structures), affecting the quality of the project and increasing the cost of later maintenance.

[0005] In response to the current situation and actual engineering needs, this invention discloses a curing agent suitable for anchor cable grouting bodies in soft soil areas, which can replace cement to solve the problems of foundation pit instability and excessive deformation. Summary of the Invention

[0006] The purpose of this invention is to provide a method for preparing a curing agent suitable for anchor cable grouting bodies in soft soil areas, aiming to solve the problems of pit instability and excessive deformation in soft soil areas in the prior art.

[0007] This invention is implemented as follows, applicable to the preparation method of curing agent for anchor cable grouting bodies in soft soil areas, comprising the following preparation steps:

[0008] 1) Place cement and water in a mixer and mix them to form a cement solution;

[0009] 2) Add emulsified asphalt to the cement solution and stir to form an emulsion;

[0010] 3) Add water-reducing agent and defoamer to the emulsion, and stir and mix the emulsion, water-reducing agent and defoamer to form a curing agent.

[0011] Furthermore, in preparation step 3), the defoamer is tributyl phosphate.

[0012] Furthermore, in the preparation step 3), the water-reducing agent is a polycarboxylate water-reducing agent, the polycarboxylate water-reducing agent is a liquid, and the solid content of the polycarboxylate water-reducing agent is 50%.

[0013] Furthermore, in preparation step 2), the solid content of the emulsified asphalt is 40%-60%.

[0014] Furthermore, in preparation step 2), the preparation steps of the emulsified asphalt are as follows:

[0015] 2.1) Dissolve the emulsifier in water to form an emulsion solution;

[0016] 2.2) Heating the asphalt to a molten state to form molten asphalt;

[0017] 2.3) The molten asphalt is poured into the emulsion solution to form a mixture. The mixture is then placed in a high-speed mixer and stirred at high speed to mix the asphalt in granular form in the emulsion solution, thus forming the emulsion asphalt.

[0018] Furthermore, in preparation step 2.1), the emulsifier is hexadecyltrimethylammonium bromide.

[0019] Furthermore, in preparation step 2.3), the mass ratio of the asphalt to the emulsifier is 100:(2-8).

[0020] Furthermore, in the preparation step 2.3), during the high-speed stirring process of the emulsion solution in the high-speed mixer, the molten asphalt heated to above 140°C and in a hot-melt state is dispersed and falls into the emulsion solution being stirred at high speed.

[0021] Above the high-speed mixer is a heater for heating asphalt into molten asphalt. The heater has a heating chamber, and the bottom of the heating chamber has a bottom wall with multiple lower drain holes. The heating chamber has a rotating plate that is rotatably arranged and attached to the bottom wall. The rotating plate has multiple upper drain holes with a diameter larger than that of the lower drain holes.

[0022] In preparation step 2.3), the asphalt is placed in the heating chamber, and the asphalt in the heating chamber is heated to form molten asphalt. Then, the rotating plate is rotated. When the upper and lower drain holes are aligned and connected, the molten asphalt passes through the upper and lower drain holes in sequence and falls into the emulsion solution in the high-speed mixer.

[0023] Furthermore, the heating chamber is provided with a partition, which divides the heating chamber into an upper chamber and a lower chamber. The rotating plate is located in the lower chamber, and the bottom wall is formed at the bottom of the lower chamber. The partition is provided with a plurality of micropores, the diameter of which is smaller than the diameter of the granular asphalt.

[0024] In preparation step 2.3), the asphalt is placed in the upper cavity, and the asphalt in the upper cavity is heated to form molten asphalt. The molten asphalt falls into the lower cavity through multiple micro-holes. The rotating plate in the lower cavity rotates. When the upper and lower drain holes are aligned and connected, the molten asphalt falls into the emulsion solution in the high-speed mixer in sequence through the upper and lower drain holes.

[0025] Furthermore, along the horizontal direction, the partition is wavy and curved in multiple segments, forming multiple protrusions and multiple recesses. The protrusions and recesses are arranged adjacent to each other, and the protrusions and recesses are arranged in a curved manner.

[0026] Compared with existing technologies ， The present invention provides a method for preparing a curing agent for anchor cable grouting bodies in soft soil areas. It uses a combination of emulsified asphalt and cement to improve the shear resistance of cement. Compared with cement grouting, the method of using the present invention to reinforce soft soil areas with anchor cable grouting bodies can significantly improve the mechanical properties and water resistance of the solidified soft soil, reduce the risk of engineering construction, enhance the durability of existing buildings and structures, reduce the possibility of uneven settlement, and solve the problems of foundation pit instability and excessive deformation in soft soil areas. Attached Figure Description

[0027] Figure 1 This is a schematic flowchart of the method for preparing a curing agent for anchor cable grouting bodies in soft soil areas provided by the present invention;

[0028] Figure 2 This is a cross-sectional structural diagram of the heater provided by the present invention.

[0029] In the figure: heater 10, rotating plate 20, partition 30, heating chamber 11, bottom wall 12, lower drain hole 13, upper cavity 14, lower cavity 15, upper drain hole 21, micro hole 31, protrusion 32, and depression 33. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0031] The implementation of the present invention will be described in detail below with reference to specific embodiments.

[0032] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this invention, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0033] Reference Figure 1-2 The image shows a preferred embodiment of the present invention.

[0034] A method for preparing a curing agent suitable for anchor cable grouting bodies in soft soil areas includes the following preparation steps:

[0035] 1) Place cement and water in a mixer and mix them to form a cement solution;

[0036] 2) Add emulsified asphalt to the cement solution and stir to form an emulsion;

[0037] 3) Add water-reducing agent and defoamer to the emulsion, stir and mix the emulsion, water-reducing agent and defoamer to form a curing agent.

[0038] The above-mentioned method for preparing a curing agent for anchor cable grouting in soft soil areas uses emulsified asphalt and cement as a compound admixture to improve the shear resistance of cement. Compared with cement grouting, the method of using anchor cable grouting to reinforce soft soil in soft soil areas can significantly improve the mechanical properties and water resistance of the solidified soft soil, reduce the risk of engineering construction, enhance the durability of existing buildings and structures, reduce the possibility of uneven settlement, and solve the problems of foundation pit instability and excessive deformation in soft soil areas.

[0039] In preparation step 3), the defoamer is tributyl phosphate.

[0040] In preparation step 3), the water-reducing agent is a polycarboxylate water-reducing agent, which is a liquid and has a solid content of 50%.

[0041] In preparation step 2), the solid content of the emulsified asphalt is 40%-60%.

[0042] In step 2), the preparation steps for emulsified asphalt are as follows:

[0043] 2.1) Dissolve the emulsifier in water to form an emulsion solution;

[0044] 2.2) Heating the asphalt to a molten state to form molten asphalt;

[0045] 2.3) The molten asphalt is poured into the emulsion solution to form a mixture. The mixture is then placed in a high-speed mixer and stirred at high speed so that the asphalt is mixed in the emulsion solution in a granular form to form emulsified asphalt.

[0046] In preparation step 2.1), the emulsifier is hexadecyltrimethylammonium bromide.

[0047] In preparation step 2.3), the mass ratio of asphalt to emulsifier is 100:(2-8).

[0048] Preparation of emulsified asphalt

[0049] First, a certain amount of CTAB is dissolved in a certain amount of water to prepare a uniform and stable CTAB aqueous solution. The corresponding amount of CTAB aqueous solution is weighed using an electronic balance for later use. A certain amount of asphalt is weighed and heated to molten temperature at 140°C. The asphalt is then poured into the pre-prepared CTAB aqueous solution (the mass ratio of asphalt to emulsifier is controlled to be 100:(2-8)). The mixture is stirred at high speed using a high-speed mixer (speed 300-12000 r / min) so that the asphalt is evenly distributed in the CTAB aqueous solution in the form of fine particles, thereby preparing emulsified asphalt.

[0050] According to the above-mentioned emulsified asphalt, its solid content is 40% to 60%. During the mixing process, a certain amount of tributyl phosphate defoamer is added, with a dosage of 0.1% to 0.8%. The main purpose is to reduce the bubble content to ensure the stability of the emulsified asphalt system.

[0051] The main components of this curing agent include: cement, emulsifier, asphalt, defoamer, and polycarboxylate superplasticizer.

[0052] 1. Cement: Cement is a hydraulic cementitious material, and its hydration reaction is a complex chemical reaction process. The various components undergo hydration reactions simultaneously at different rates, and different mineral components influence each other during the hydration process. The most abundant mineral component in cement is silicate compounds, which are key components determining the hydration properties and related performance of cement. Its main mineral components are tricalcium silicate, dicalcium silicate, tricalcium aluminate, and tetracalcium aluminoferrite. After hydration, these mineral components form hydrated calcium silicate, hydrated calcium aluminate, and calcium hydroxide. They interlock to form a three-dimensional network framework structure, cementing soil particles and filling voids.

[0053] 2. Emulsifier: The emulsifier is the main component of emulsified asphalt. It is a surfactant used for asphalt emulsification. It can significantly reduce the surface tension of water to a certain extent and change the interfacial properties and state of the asphalt-water mixture, so that the asphalt and water can be fully mixed to produce an emulsification effect. The present invention selects a cationic emulsifier: hexadecyltrimethylammonium bromide (CTAB).

[0054] 3. Asphalt: Asphalt is an organic binder composed of non-metallic derivatives and hydrocarbons. It is black or dark brown in color, usually exists in solid form, and is insoluble in water. Due to its good anti-corrosion and moisture-proof properties, it is widely used in the field of building construction. This invention uses 90# asphalt.

[0055] 4. Defoamer: Tributyl phosphate (C4H9)3PO4, with a density of 0.978×103kg / m3, its main function is to stabilize and defoam, and enhance the emulsification performance of asphalt.

[0056] 5. Polycarboxylate superplasticizer: Liquid superplasticizer with a solid content of 50%.

[0057] In this embodiment, during the preparation step 2.3), while the emulsion solution is being stirred at high speed in a high-speed mixer, the molten asphalt heated to above 140°C and in a hot-melt state is broken up and falls into the emulsion solution being stirred at high speed.

[0058] Above the high-speed mixer is a heater 10 for heating asphalt into molten asphalt. The heater 10 has a heating chamber 11, and the bottom of the heating chamber 11 has a bottom wall 12. The bottom wall 12 has multiple lower drain holes 13. The heating chamber 11 has a rotating plate 20 that is rotatably arranged. The rotating plate 20 is attached to the bottom wall 12. The rotating plate 20 has multiple upper drain holes 21. The diameter of the upper drain holes 21 is larger than the diameter of the lower drain holes 13.

[0059] In preparation step 2.3), asphalt is placed in heating chamber 11. After heating the asphalt in heating chamber 11 to form molten asphalt, rotating plate 20 is rotated. When the upper drain hole 21 and the lower drain hole 13 are aligned and connected, the molten asphalt passes through the upper drain hole 21 and the lower drain hole 13 in sequence and falls into the emulsion solution in the high-speed mixer.

[0060] The heater 10 heats the asphalt at high temperature through the heating chamber 11. The heating chamber 11 utilizes the rotation of the rotating plate 20 on the bottom wall 12 to grind and cut the asphalt particles on the bottom wall 12, thereby improving the melting state of the asphalt. The upper drain hole 21 and the lower drain hole 13 allow the molten asphalt to fall sequentially into the emulsion solution in the high-speed mixer in order to improve the thorough mixing effect between the molten asphalt and the emulsion solution.

[0061] In this embodiment, the heating chamber 11 is provided with a partition 30, which divides the heating chamber 11 into an upper chamber 14 and a lower chamber 15. The rotating plate 20 is located in the lower chamber 15, and the bottom wall 12 is formed at the bottom of the lower chamber 15. The partition 30 is provided with a plurality of micro-holes 31, the diameter of which is smaller than the diameter of the granular asphalt.

[0062] In preparation step 2.3), asphalt is placed in the upper cavity 14. After the asphalt in the upper cavity 14 is heated to form molten asphalt, the molten asphalt falls into the lower cavity 15 through multiple micro-holes 31. The rotating plate 20 in the lower cavity 15 rotates. When the upper drain hole 21 and the lower drain hole 13 are aligned and connected, the molten asphalt sequentially passes through the upper drain hole 21 and the lower drain hole 13 and falls into the emulsion solution in the high-speed mixer. In this way, the heating chamber 11 can filter the particulate asphalt through the partition 30.

[0063] In this embodiment, along the horizontal direction, the partition 30 is wavy and curved in multiple segments. The partition 30 forms multiple protrusions 32 and multiple recesses 33. The protrusions 32 and the recesses 33 are arranged adjacent to each other, and the protrusions 32 and the recesses 33 are arranged in a curved manner.

[0064] The baffle 30 can increase the flow rate of asphalt through multiple protrusions 32 and multiple recesses 33, so as to improve the heating effect of the heater 10 on the asphalt.

[0065] The preparation process of the curing agent is as follows:

[0066] Step 1: First, place the weighed cement and an appropriate amount of water into a mixer and stir slowly for 30 seconds until they are fully mixed to form a cement solution. Then, add the pre-prepared emulsified asphalt and mix quickly to form an emulsion. Take 50 to 90 parts by weight of cement and 10 to 50 parts by weight of emulsified asphalt and mix thoroughly.

[0067] Step 2: Add polycarboxylate superplasticizer and defoamer tributyl phosphate to the well-stirred emulsion. After mixing the two in a certain proportion, add an appropriate amount of cement and stir to prepare the cement curing agent of the present invention and prepare the slurry.

[0068] Using a curing agent to replace part of the cement as the anchor grout for soil reinforcement has several advantages. First, compared to adding cement alone, the curing agent reacts with the surrounding soil layers, resulting in better interfacial strength, greater cohesion and friction, and improved overall stability of the soil-anchor interface. Second, compared to adding cement alone, using a curing agent to replace part of the cement as the anchor grout provides higher shear strength. Therefore, different design schemes can be selected to improve the stability of the system depending on the geological conditions of the foundation pit excavation.

[0069] To test the performance of the curing agent described in this invention, the following experiment was designed for verification:

[0070] Example 1:

[0071] A method for preparing a curing agent suitable for anchor cable grouting in soft soil areas, the preparation steps of which are as follows:

[0072] 1) Preparation of emulsified asphalt: Prepare CTAB aqueous solution, heat 90# petroleum asphalt to 140℃, mix 60 parts of petroleum asphalt with 40 parts of CTAB aqueous solution, and then stir at a high speed of 2000r / min for 10min to obtain emulsified asphalt.

[0073] 2) Preparation of emulsified asphalt-cement-sludge composite system: Mix the prepared emulsified asphalt and cement at a ratio of 1:9, add a certain amount of water and sludge, stir slowly for 2 minutes, then stir quickly for 3 minutes to obtain emulsified asphalt-cement-sludge slurry. After the slurry is mixed evenly, pour it into a mold and cure it according to standard until the specified age. The compressive strength, bond strength and shear strength parameters at 28 days are shown in Table 1.

[0074] Table 1. Performance Indicators of Cement-Soil and Solidified Soil

[0075]

[0076] Example 2:

[0077] (1) Preparation of emulsified asphalt: Prepare CTAB aqueous solution, heat 90# petroleum asphalt to 140℃, mix 70 parts of petroleum asphalt with 30 parts of CTAB aqueous solution, and then stir at a high speed of 2000r / min for 10min to obtain emulsified asphalt.

[0078] (2) Preparation of emulsified asphalt-cement-sludge composite system: Mix the prepared emulsified asphalt and cement in a ratio of 2:8, add a certain amount of water and sludge, stir slowly for 2 minutes, then stir quickly for 3 minutes to obtain emulsified asphalt-cement-sludge slurry. After the slurry is mixed evenly, pour it into the mold and cure it according to the standard until the specified age. The compressive strength, bond strength and shear strength parameters at 28 days are shown in Table 2.

[0079] Table 2 Performance Indicators of Cement-Soil and Solidified Soil

[0080]

[0081] Compared with the traditional method of reinforcement using cement grout, the present invention has the following advantages:

[0082] 1) Using an emulsified asphalt-cement composite system for anchor cable grouting reinforcement in soft soil areas can fully utilize the high compressive strength of cement-based materials and the high elasticity and flexibility of asphalt.

[0083] 2) Using an emulsified asphalt-cement composite system for anchor cable grouting reinforcement in soft soil areas can improve the shear strength and water resistance of the solidified silt soft soil, reduce the risk of engineering construction, enhance the durability of existing buildings (structures), and reduce the possibility of uneven settlement.

[0084] 3) Using an emulsified asphalt-cement composite system for anchor cable grouting reinforcement in soft soil areas results in high pull-out resistance of the anchor cables, which can reduce the self-weight of the support structure to a certain extent. It has advantages such as high construction efficiency, reliable construction quality, and saving construction time and materials, and has good prospects for engineering application.

[0085] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a curing agent suitable for anchor cable grouting bodies in soft soil areas, characterized in that, The preparation steps include the following: 1) Place cement and water in a mixer and mix them to form a cement solution; 2) Add emulsified asphalt to the cement solution and stir to form an emulsion; The preparation steps of the emulsified asphalt are as follows: 2.1) Dissolve the emulsifier in water to form an emulsion solution; 2.2) Heating the asphalt to a molten state to form molten asphalt; 2.3) The molten asphalt is poured into the emulsion solution to form a mixture. The mixture is then placed in a high-speed mixer and stirred at high speed to mix the asphalt in granular form within the emulsion solution, thus forming the emulsified asphalt. The mass ratio of the asphalt to the emulsifier is 100:(2-8). During the high-speed stirring process in the high-speed mixer, molten asphalt heated to above 140°C and in a hot-melt state is broken up and falls into the high-speed stirring emulsion. Above the high-speed mixer is a heater for heating asphalt into molten asphalt. The heater has a heating chamber, and the bottom of the heating chamber has a bottom wall with multiple lower drain holes. The heating chamber has a rotating plate that is rotatably arranged and attached to the bottom wall. The rotating plate has multiple upper drain holes with a diameter larger than that of the lower drain holes. The asphalt is placed in the heating chamber and heated to form molten asphalt. The rotating plate is then rotated. When the upper and lower drain holes are aligned and connected, the molten asphalt sequentially passes through the upper and lower drain holes and falls into the emulsion solution in the high-speed mixer. The heating chamber is provided with a partition, which divides the heating chamber into an upper chamber and a lower chamber. The rotating plate is located in the lower chamber, and the bottom wall is formed at the bottom of the lower chamber. The partition is provided with a plurality of micropores, the diameter of which is smaller than the diameter of the granular asphalt. The asphalt is placed in the upper cavity, and the asphalt in the upper cavity is heated to form molten asphalt. The molten asphalt falls into the lower cavity through multiple micro holes. The rotating plate in the lower cavity rotates. When the upper and lower drain holes are aligned and connected, the molten asphalt falls into the emulsion solution in the high-speed mixer in sequence through the upper and lower drain holes. Along the horizontal direction, the partition is wavy and curved in multiple segments, forming multiple protrusions and multiple recesses. The protrusions and recesses are arranged adjacent to each other, and the protrusions and recesses are arranged in a curved manner. 3) Add water-reducing agent and defoamer to the emulsion respectively, and stir and mix the emulsion, water-reducing agent and defoamer to form a curing agent.

2. The method for preparing a curing agent suitable for anchor cable grouting bodies in soft soil areas as described in claim 1, characterized in that, In preparation step 3), the defoamer is tributyl phosphate.

3. The method for preparing a curing agent suitable for anchor cable grouting bodies in soft soil areas as described in claim 1, characterized in that, In preparation step 3), the water-reducing agent is a polycarboxylate water-reducing agent, the polycarboxylate water-reducing agent is a liquid, and the solid content of the polycarboxylate water-reducing agent is 50%.

4. The method for preparing a curing agent suitable for anchor cable grouting bodies in soft soil areas as described in claim 1, characterized in that, In preparation step 2), the solid content of the emulsified asphalt is 40%-60%.

5. The method for preparing a curing agent suitable for anchor cable grouting bodies in soft soil areas as described in claim 1, characterized in that, In preparation step 2.1), the emulsifier is hexadecyltrimethylammonium bromide.

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