Tunnel second lining grouting agent and application of grouting slurry prepared by the same
By using a tunnel lining grouting agent mixed with cement on-site to form a grouting slurry, the problems of voids and transportation difficulties in the construction of tunnel lining concrete were solved, achieving efficient grouting and cost reduction.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- CHINA RAILWAY 12TH BUREAU GRP CO LTD
- Filing Date
- 2026-02-10
- Publication Date
- 2026-06-09
AI Technical Summary
In the current construction of tunnel secondary lining concrete, the construction of the arch concrete is prone to causing voids and gaps around the tunnel. The existing grouting materials have large transportation volume, high cost and poor effect, which makes it difficult to meet the needs of special transportation conditions.
The tunnel secondary lining grouting agent is composed of manufactured sand, fly ash, nanospheres, polycarboxylate superplasticizer, defoamer, expanding agent, rheology modifier and boric acid. It is mixed with cement on site to form a grouting slurry, which is then injected through a grouting machine. The grouting process is optimized to reduce voids.
It improved the grouting effect, reduced material costs, reduced transportation difficulties, increased grouting efficiency, and solved the problem of voids in the secondary lining concrete of tunnels.
Smart Images
Figure CN122167091A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the technical field of tunnel secondary lining concrete grouting materials, specifically relating to a tunnel secondary lining grouting agent and its application in preparing grouting slurry. Background Technology
[0002] Currently, tunnels are widely used in railway engineering. During the construction of the secondary lining concrete after tunnel excavation, the construction of the arch concrete can easily cause voids behind the secondary lining concrete and gaps between it and the tunnel perimeter. Existing technology uses grouting material to form slurry for secondary lining grouting, and the grouting effect can meet the current technical requirements. However, grouting materials are mostly processed and produced by fixed factories, which leads to problems such as large transportation volume, high cost, and poor effect at the construction site. In some projects with poor transportation conditions and some projects with special circumstances such as overseas construction, the existing grouting materials cannot meet the requirements for transportation and storage. There is a need for a new material and preparation method that can meet the construction needs through on-site operation with a small dosage to solve the above problems. Summary of the Invention
[0003] In order to overcome the shortcomings of the prior art, the purpose of this invention is to provide a tunnel secondary lining grouting agent and its application in preparing grouting slurry, so as to solve the problem of tunnel secondary lining concrete voids being filled by preparing a new material with on-site cement to meet construction needs.
[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A tunnel secondary lining grouting agent, characterized in that it comprises the following components by mass fraction: 10-12 parts manufactured sand, 5-8 parts fly ash, 10-15 parts nanospheres, 0.19-0.25 parts polycarboxylate superplasticizer, 0.031-0.038 parts defoamer, 0.031-0.040 parts expanding agent, 0.040-0.045 parts rheology modifier, and 0.010-0.018 parts boric acid.
[0005] Furthermore, a tunnel secondary lining grouting agent is characterized by comprising the following components by mass fraction: 10 parts manufactured sand, 10 parts nano-microspheres, 5 parts fly ash, 0.24 parts polycarboxylate superplasticizer, 0.031 parts defoamer, 0.031 parts expansion agent, 0.040 parts rheology modifier, and 0.010 parts boric acid.
[0006] The defoamer is composed of silica and polypropylene glycol monobutyl ether in a mass ratio of 35-40:60-65.
[0007] The expanding agent is composed of heavy calcium carbonate powder and casein in a mass ratio of 15-20:75-80.
[0008] The rheology modifier is composed of heavy calcium carbonate powder and polysaccharide polymer in a mass ratio of 5-20:80-95.
[0009] The nanospheres are composed of silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, etc., with silicon dioxide and aluminum oxide accounting for more than 70% of the main components.
[0010] The cement is a low-alkali ordinary Portland cement with an alkali content of <0.06, and the amount of cement used is 75 parts.
[0011] The parent rock of the manufactured sand is limestone, with a sub-Glycol value of no more than 1.2 and a fineness of 40-70 mesh.
[0012] The fly ash mentioned is Grade I fly ash with a fineness of ≤12% residue on a 45µm sieve, a water requirement ratio of ≤95%, a loss on ignition of ≤5%, and a 28-day activity index of ≥95%.
[0013] An application of a tunnel secondary lining grouting agent for preparing grout, characterized by comprising the following steps: Step 1: Preparation. Two hours after the completion of the tunnel secondary lining concrete construction, preparations for grouting are carried out, including installing the grouting machine and connecting the grouting pipeline, and setting up a work area and warning area around the site. Step 2: Grout preparation. First, run the entire process with clean water. After the grouting pressure reaches the point where the pipeline and connections are properly sealed, drain the water. After setting the raw material ratio on the grouting machine, add cement to bin 1 of the feeding area and grouting agent to bin 2 of the feeding area. Fill the water tank of the grouting machine with water to prepare for grout preparation. Step 3: Grout mixing. First, add 80%~90% water and start the mixer. The mixing speed should not be less than 50 r / min. While mixing, add 50% cement and 100% grouting agent. After mixing for 1 minute, slowly add the remaining 10%~20% water and 50% cement. After all the powder is added to the mixing bucket, mix for 3 minutes. After the initial fluidity is tested and found to be qualified, the mixture is passed through a 3mm*3mm filter screen and flows into the storage tank. Continue mixing at a speed of not less than 50 r / min. Step 4, Grouting. Connect the grouting pipe to the first grouting hole and start grouting. While grouting, continue mixing the grout as in Step 3. When a continuous and stable grout flows out of the second grouting hole, install the grouting pipe of the grouting machine into the second grouting hole for grouting. When a continuous and stable grout flows out of the third grouting hole, close the third grouting hole and continue grouting. After the grout flows out of the end mold of the grouting trolley, stop grouting. Step 5: After 10-15 minutes of grouting, perform a second grouting. Stop grouting once no grout flows out. Step 6: After demolding, use radar to scan and detect any voids. If any voids are found, perform secondary drilling and grouting.
[0014] The grouting agent is produced by a forced horizontal mixer with automatic metering. The mixing time for the grouting agent is no less than 25 minutes. The grouting machine is a screw grouting machine, and the mixing time for the grout is no less than 4 minutes.
[0015] The grouting agent is prepared by mixing the raw materials according to their proportions and ratios. After passing the trial mixing and testing with cement, it is placed in a qualified area for use. On-site mixing involves sequentially adding water (100%), cement (50%), grouting agent (100%), and cement (50%), with a water-to-material ratio of 0.18-0.20. The on-site mixing equipment is a high-speed mortar mixer with a speed of not less than 500 rpm, and the grouting machine pressure is not less than 10 MPa, with an accuracy of not less than 0.2 MPa.
[0016] The beneficial effects of this invention are: The tunnel secondary lining grouting agent and grout preparation method provided by this invention are prepared using manufactured sand, fly ash, nanospheres, polycarboxylate superplasticizer, defoamer, expanding agent, rheology modifier, and boric acid as main raw materials. On-site, the grouting agent, silicate cement, and water are mixed in proportion and sequence using a tunnel secondary lining grouting machine to form a grout for formwork injection into the tunnel secondary lining concrete. The grouting material prepared by this invention improves the flowability, water retention, flexural strength, and compressive strength of the tunnel secondary lining concrete, contributing to the overall performance improvement of tunnel grouting materials. This invention optimizes the original factory-processed grouting material by directly adding water and mixing on-site. Instead, the grouting agent is transported to the site, and then cement and water are mixed using a grouting machine to form a grout. This achieves formwork injection, reduces the problem of voids in the secondary lining concrete, improves efficiency, reduces the difficulties of transporting large quantities of grouting material and the quality problems of moisture absorption and caking, and significantly reduces material costs, demonstrating significant effectiveness. Attached Figure Description
[0017] Figure 1 This is a flowchart of the construction process of the present invention. Detailed Implementation
[0018] The present invention will be further described below with reference to the accompanying drawings, but the present invention is not limited to the following embodiments. To investigate the effects of the amount of manufactured sand and various chemical reagents added on the performance and strength of tunnel grouting materials, performance tests were conducted on the samples through comparative experiments.
[0019] For fluidity determination, refer to the "Technical Specification for Application of Cement-based Grouting Materials" (GB / T50448-2015) and use calipers to measure the maximum diffusion diameter of the bottom surface and the diameter in the direction perpendicular to it. Calculate the average value as the initial value of fluidity. The test results should be accurate to 1 mm.
[0020] The vertical expansion rate shall be in accordance with the "Technical Specification for Application of Cement-based Grouting Materials" (GB / T50448-2015) and the instruments and equipment for the dial gauge method shall comply with the relevant provisions of the current national standard "Technical Specification for Application of Concrete Admixtures" (GB50119-2013).
[0021] Flexural and compressive strength tests: The flexural and compressive strengths of the grouting material were measured at 1d, 3d, and 28d. The specimen preparation and testing methods followed GB / T17671-2020, "Test Method for Strength of Cement Mortar (ISO Method)". Rectangular blocks with dimensions of 40mm × 40mm × 160mm were prepared, and flexural and compressive strength tests were conducted at the corresponding 1d, 3d, and 28d ages using the traditional center-loading method.
[0022] In the following examples, the defoamer is composed of silica and polypropylene glycol monobutyl ether in a mass ratio of 35-40:60-65.
[0023] The expanding agent is composed of heavy calcium carbonate powder and casein, with a mass ratio of 15-20:75-80.
[0024] The rheology modifier is composed of heavy calcium carbonate powder and polysaccharide polymer in a mass ratio of 5-20:80-95.
[0025] The cement is a low-alkali ordinary Portland cement with an alkali content of <0.06%, and the amount of cement used is 75 parts.
[0026] The nanospheres are composed of silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, etc., with silicon dioxide and aluminum oxide accounting for more than 70% of the main components. Example 1
[0027] A method for preparing a tunnel secondary lining grouting agent and grout, comprising the following raw materials in parts by weight: 75 parts silicate cement, 10 parts manufactured sand, 15 parts fly ash, 0.19 parts polycarboxylate superplasticizer, 0.038 parts defoamer, 0.040 parts expansion agent, 0.045 parts rheology modifier, and 0.01 parts boric acid.
[0028] To investigate the effects of various materials on the performance and strength of tunnel grouting materials, three groups of grouting material samples A1 were prepared during the preparation process, and the performance of the samples was tested.
[0029]
[0030] Example 2
[0031] A method for preparing a tunnel secondary lining grout includes the following raw materials in parts by weight: 75 parts silicate cement, 25 parts nanospheres, 0.21 parts polycarboxylate superplasticizer, 0.037 parts defoamer, 0.038 parts expanding agent, 0.043 parts rheology modifier, and 0.018 parts boric acid. To investigate the effects of various materials on the performance and strength of the tunnel grout, three groups of grout samples (B1) were prepared and their performance was tested.
[0032]
[0033] Example 3
[0034] A method for preparing a tunnel secondary lining grouting agent and grout, comprising the following raw materials in parts by weight: 75 parts silicate cement, 10 parts manufactured sand, 5 parts fly ash, 7 parts nanospheres, 3 parts stone powder, 0.23 parts polycarboxylate superplasticizer, 0.034 parts defoamer, 0.033 parts expansion agent, 0.043 parts rheology modifier, and 0.025 parts boric acid.
[0035] To investigate the effects of various materials on the performance and strength of tunnel grouting materials, three groups of grouting material samples (C1) were prepared during the preparation process, and the performance of the samples was tested.
[0036] Example 4
[0037] A method for preparing a tunnel secondary lining grouting agent and grout, comprising the following raw materials in parts by weight: 75 parts silicate cement, 10 parts manufactured sand, 5 parts fly ash, 10 parts nanospheres, 0.24 parts polycarboxylate superplasticizer, 0.031 parts defoamer, 0.031 parts expansion agent, 0.040 parts rheology modifier, and 0.01 parts boric acid.
[0038] To investigate the effects of various materials on the performance and strength of tunnel grouting materials, three groups of grouting material samples (D1) were prepared during the preparation process, and the performance of the samples was tested.
[0039]
[0040] Example 5
[0041] A method for preparing a tunnel secondary lining grouting agent and grout, comprising the following raw materials in parts by weight: 75 parts silicate cement, 12 parts manufactured sand, 3 parts fly ash, 5 parts nanospheres, 0.25 parts polycarboxylate superplasticizer, 0.031 parts defoamer, 0.031 parts expansion agent, 0.040 parts rheology modifier, and 0.013 parts boric acid.
[0043] To investigate the effects of various materials on the performance and strength of tunnel grouting materials, three groups of grouting material samples E1 were prepared during the preparation process, and the performance of the samples was tested.
[0044] The results analysis shows that, based on Examples 1-5, the flexural strength, compressive strength, fluidity, and bonding strength of the grouting material change to varying degrees with the change in the materials used. The change in fluidity with the addition of different raw materials and the increase in the amount of water-reducing agent has a certain impact on the flexural strength and bonding strength ratio.
[0045] Based on the analysis results, the following performance tests were conducted on the samples: 75 parts silicate cement, 10 parts manufactured sand, 5 parts fly ash, 10 parts nanospheres, 0.24 parts polycarboxylate superplasticizer, 0.031 parts defoamer, 0.031 parts expansion agent, 0.040 parts rheology modifier, and 0.01 parts boric acid. The performance of the samples was tested using the D1 method.
[0046]
[0047] The performance results show a significant improvement in fluidity, a moderate expansion rate, and flexural and compressive strength that meet the specifications, with a significant improvement in the bond strength ratio.
[0048] The defoamer is composed of silica and polypropylene glycol monobutyl ether in a mass ratio of 35-40:60-65.
[0049] The expanding agent is composed of heavy calcium carbonate powder and casein, with a mass ratio of 15-20:75-80.
[0050] The rheology modifier is composed of heavy calcium carbonate powder and polysaccharide polymer in a mass ratio of 5-20:80-95.
[0051] The nanospheres are composed of silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, etc., with silicon dioxide and aluminum oxide accounting for more than 70% of the main components.
[0052] The cement is a low-alkali ordinary Portland cement with an alkali content of <0.06%, and the amount of cement used is 75 parts.
[0053] The parent rock of the manufactured sand is limestone, the sub-blue value of the stone powder is no greater than 1.2, and the fineness is 40-70 mesh.
[0054] The fly ash is Grade I fly ash with a fineness of ≤12% residue on a 45µm sieve, a water requirement of ≤95%, a loss on ignition of ≤5%, and a 28-day activity index of ≥95%.
[0055] like Figure 1 As shown, a method for preparing a tunnel secondary lining grouting agent and grout includes: S100: Preparatory work. Two hours after the completion of the tunnel secondary lining concrete construction, grouting preparation work will be carried out, including installing the grouting machine and connecting the grouting pipeline, and setting up a work area and warning area around the site.
[0056] S200: Grout preparation. First, use clean water to perform the entire process. After the grouting pressure reaches the point where the pipeline and connections are properly sealed, drain the water. After setting the raw material ratio on the grouting machine, add cement to bin 1 of the feeding area and grouting agent to bin 2 of the feeding area. Fill the water tank of the grouting machine with water to prepare for grout preparation.
[0057] S300: Grout mixing. First, add 80%~90% water, start the mixer and mix at a speed not less than 50 r / min. While mixing, add 50% cement and 100% grouting agent. After mixing for 1 minute, slowly add the remaining 10%~20% water and 50% cement. After all the powder is added to the mixing bucket, mix for 3 minutes. After the initial flowability is qualified, the mixture is passed through a 3mm*3mm filter screen and flows into the storage tank. Continue mixing at a speed not less than 50 r / min.
[0058] S400: Grouting. Connect the grouting pipe to the first grouting hole and begin grouting. While grouting, continue mixing the grout as per step three. Once a continuous and stable flow of grout comes out of the second grouting hole, install the grouting pipe of the grouting machine into the second grouting hole for grouting. Once a continuous and stable flow of grout comes out of the third grouting hole, close the third grouting hole and continue grouting. Stop grouting once the grout flows out of the end mold of the grouting trolley.
[0059] S500: After 10-15 minutes of grouting, perform a second grouting. Stop grouting once no grout flows out.
[0060] S600: After demolding, radar is used for scanning and detection. If local voids are found, secondary drilling and grouting are performed.
Claims
1. A tunnel secondary lining grouting agent, characterized in that, By mass fraction, it includes the following components: 10-12 parts manufactured sand, 5-8 parts fly ash, 10-15 parts nanospheres, 0.19-0.25 parts polycarboxylate superplasticizer, 0.031-0.038 parts defoamer, 0.031-0.040 parts expanding agent, 0.040-0.045 parts rheology modifier, and 0.010-0.018 parts boric acid.
2. The tunnel secondary lining grouting agent according to claim 1, characterized in that, The composition by mass fraction includes: 10 parts manufactured sand, 10 parts nano-beads, 5 parts fly ash, 0.24 parts polycarboxylate superplasticizer, 0.031 parts defoamer, 0.031 parts expanding agent, 0.040 parts rheology modifier, and 0.010 parts boric acid.
3. The tunnel secondary lining grouting agent according to claim 1, characterized in that, The defoamer is composed of silica and polypropylene glycol monobutyl ether in a mass ratio of 35-40:60-65.
4. The tunnel secondary lining grouting agent according to claim 1, characterized in that, The expanding agent is composed of heavy calcium carbonate powder and casein in a mass ratio of 15-20:75-80.
5. The tunnel secondary lining grouting agent according to claim 1, characterized in that, The rheology modifier is composed of heavy calcium carbonate powder and polysaccharide polymer in a mass ratio of 5-20:80-95.
6. The tunnel secondary lining grouting agent according to claim 1, characterized in that, The nanospheres are composed of silicon dioxide, aluminum oxide, calcium oxide, magnesium oxide, etc., with silicon dioxide and aluminum oxide accounting for more than 70% of the main components.
7. The tunnel secondary lining grouting agent according to claim 1, characterized in that, The cement is a low-alkali ordinary Portland cement with an alkali content of <0.06, and the amount of cement used is 75 parts.
8. The tunnel secondary lining grouting agent according to claim 1, characterized in that, The parent rock of the manufactured sand is limestone, with a sub-Glycol value of no more than 1.2 and a fineness of 40-70 mesh.
9. The tunnel secondary lining grouting agent according to claim 1, characterized in that, The fly ash mentioned is Grade I fly ash with a fineness of ≤12% residue on a 45µm sieve, a water requirement ratio of ≤95%, a loss on ignition of ≤5%, and a 28-day activity index of ≥95%.
10. An application of a tunnel secondary lining grouting agent in preparing grout, characterized in that, Includes the following steps: Step 1: Preparation. Two hours after the completion of the tunnel secondary lining concrete construction, preparations for grouting are carried out, including installing the grouting machine and connecting the grouting pipeline, and setting up a work area and warning area around the site. Step 2: Grout preparation. First, run the entire process with clean water. After the grouting pressure reaches the point where the pipeline and connections are properly sealed, drain the water. After setting the raw material ratio on the grouting machine, add cement to bin 1 of the feeding area and grouting agent to bin 2 of the feeding area. Fill the water tank of the grouting machine with water to prepare for grout preparation. Step 3: Grout mixing. First, add 80%~90% water and start the mixer. The mixing speed should not be less than 50 r / min. While mixing, add 50% cement and 100% grouting agent. After mixing for 1 minute, slowly add the remaining 10%~20% water and 50% cement. After all the powder is added to the mixing bucket, mix for 3 minutes. After the initial fluidity is tested and found to be qualified, the mixture is passed through a 3mm*3mm filter screen and flows into the storage tank. Continue mixing at a speed of not less than 50 r / min. Step 4, Grouting. Connect the grouting pipe to the first grouting hole and start grouting. While grouting, continue mixing the grout as in Step 3. When a continuous and stable grout flows out of the second grouting hole, install the grouting pipe of the grouting machine into the second grouting hole for grouting. When a continuous and stable grout flows out of the third grouting hole, close the third grouting hole and continue grouting. After the grout flows out of the end mold of the grouting trolley, stop grouting. Step 5: After 10-15 minutes of grouting, perform a second grouting. Stop grouting once no grout flows out. Step 6: After demolding, use radar to scan and detect any voids. If any voids are found, perform secondary drilling and grouting.