Quick-setting ultrahigh-strength rock-soil polymer grouting material and preparation method thereof

Abstract

The invention discloses a quick-setting ultrahigh-strength rock-soil polymer grouting material and a preparation method thereof, the material is composed of ball-milled powder and an auxiliary agent, the ball-milled powder comprises silicate clinker, alumina clinker, gypsum, silicon powder, mineral powder and fly ash; the auxiliaries comprise water-reducing polycarboxylic acid, slump-retaining polycarboxylic acid, an early strength agent, a retarder, a thickening agent and a defoaming agent. By optimizing the component proportion and the preparation process, the material disclosed by the invention is excellent in flowability, final setting time, early strength and later strength, and is suitable for the fields of geotechnical engineering and rapid repair.

Description

Technical Field

[0001] The invention relates to a road trenchless grouting material and a use method thereof, and in particular to a quick-setting ultra-high-strength geotechnical polymer grouting material and a preparation method thereof. Background Art

[0002] Geopolymer grouting technology is a new type of grouting technology developed by utilizing the excellent properties of geopolymer grouting materials. This technology is widely used in road reinforcement projects because of its simple operation, rapidity and effectiveness, especially its non-excavation treatment of various road diseases such as faults, subsidence, mud pumping, mud overflow, road surface subsidence, and fast reinforcement and repair speed.

[0003] In view of the many shortcomings of commonly used slurry materials, geopolymer grouting materials have gradually emerged. Geopolymer was first proposed and applied by French scientist Joseph Davidovits in 1985. Geopolymer grouting materials mainly use materials such as industrial waste mineral active ingredients. They are made of raw materials such as slag, fly ash, metakaolin, alkali activator and admixtures in a professional chemical factory and mixed and prepared according to proportion. They are alkali-activated inorganic high-performance polymer cementing materials that are mixed with water in a prescribed proportion at the place of use. Compared with cement, modified geopolymer grouting materials have more obvious performance advantages, which are mainly reflected in the following aspects:

[0004] First, it has early strength and fast setting. It can solidify quickly, has high early strength, and continuously increases in strength in the later period. It has a short maintenance and reinforcement cycle, and can be opened to traffic early. It is especially suitable for sections with heavy traffic pressure such as highways and urban roads.

[0005] Second, high fluidity. The slurry has high fluidity and is pressed into the damaged roadbed and base under a certain pressure. The modified geopolymer grouting material can be squeezed into the fine gaps through filling, penetration and compaction.

[0006] The third is the alkali activation property. The alkali activator can activate the inert silica and alumina in the base or roadbed fill, and can undergo a polymerization reaction with the mineral active components in the roadbed base to form a stone body, thereby improving the overall bearing capacity of the road.

[0007] Geopolymer grouting materials were first promoted in Shanghai in 2015, and then gradually promoted and applied in Jiangsu, Zhejiang, Shandong, Henan and other provinces, and have achieved good social and economic value. However, after several years of application, the problems of geopolymers have gradually emerged. At present, after the completion of geopolymer grouting, it takes 3 to 6 hours of curing before it can be opened to traffic. At present, the market is in urgent need of a material that does not require curing time after the completion of grouting and can be directly opened to traffic. Summary of the invention

[0008] The purpose of the present application is to provide a non-excavation grouting material for roads and a method for using the same, wherein the material has the characteristics of good fluidity, rapid strength growth, early strength and rapid later strength growth.

[0009] In order to achieve the above objectives, this application adopts the following technical solutions:

[0010] A high early strength rapid setting grouting material, characterized in that it is composed of ball milled powder and additives, wherein the ball milled powder includes:

[0011] 50-60 parts of silicate clinker;

[0012] 5-15 parts of alumina clinker;

[0013] 5-10 parts of gypsum;

[0014] 5-8 parts of silicon powder;

[0015] 8-10 parts of mineral powder;

[0016] 8-10 parts of fly ash; the mass ratio of the ball-milled powder to the additives is: every 1000 parts of the ball-milled powder, including the following additives:

[0017] 2-4 parts of water-reducing polycarboxylic acid;

[0018] 1-2 parts of collapse-resistant polycarboxylic acid;

[0019] 1 to 1.5 parts of early strength agent;

[0020] Retarder 0.5-0.8 parts;

[0021] Thickener 0.4-0.6 parts;

[0022] Defoamer 0.2-0.3 parts. Early strength agent is composed of the following components: sodium sulfate, calcium chloride, triethanolamine, citric acid, nano silicon, sodium silicate. Synergistic effect of sodium sulfate and calcium chloride: SO4 2- With Ca 2+ Ions synergistically promote the formation of ettringite and CSH gel, significantly improving early strength. This combination effectively controls the setting time and avoids cracking caused by too fast reaction.

[0023] Synergistic effect of triethanolamine and nano-silicon powder: triethanolamine accelerates the hydration reaction, and nano-silicon powder provides crystal nuclei, which significantly improves the reaction efficiency and product quality. The crystal nuclei and reaction products fill the pores together, improving the density and durability of concrete.

[0024] The combination of water reducer and retarder: while improving fluidity, ensure that the setting time matches the construction requirements, taking into account both early strength and operability.

[0025] The method for preparing the above-mentioned quick-setting ultra-high-strength geotechnical polymer grouting material comprises the following steps:

[0026] (1) Preparation of ball mill powder: adding silicate clinker, alumina clinker, gypsum, silicon powder, mineral powder and fly ash into a ball mill according to the proportion and stirring. The speed of the ball mill is 200-300 rad / min and the grinding time is 15-20 min.

[0027] (2) Preparation of additives: adding water-reducing polycarboxylic acid and collapse-retaining polycarboxylic acid in proportion, adjusting the speed of the ball mill to 600-800 rad / min and stirring for 5-8 minutes; then adding early strength agent, retarder, thickener and defoamer in proportion, and stirring at 1200-1500 rad / min for 15-20 minutes;

[0028] (3) Add the additive obtained in step (2) to the ball-milled powder obtained in step (1), and stir at 500 to 800 rad / min for 10 to 15 minutes to obtain a grouting material. The water-cement ratio of the grouting material is 0.28-0.32.

[0029] The above-mentioned grouting material obtained has the following characteristics:

[0030] 1. Optimized performance: Through refined ratio design, the material achieves a balance between high early strength and long-term stability, and is suitable for a variety of construction environments.

[0031] 2. No maintenance required: After final setting, it can meet the road traffic requirements, without the need for additional wet maintenance or covering measures, greatly shortening the construction time.

[0032] From the perspective of engineering construction, no maintenance is required which can greatly save construction costs and shorten construction period.

[0033] (1) Labor cost saving: In conventional grouting construction, special personnel need to be arranged to perform regular inspections, watering, covering and other maintenance operations on the grouting area during the maintenance period to ensure the normal development of material properties. Taking a medium-sized tunnel grouting project as an example, the maintenance period is usually 7-14 days, during which at least 2-3 professional maintenance personnel are required to carry out daily maintenance work. Assuming that the daily wage of each maintenance personnel is 300 yuan, the labor cost of the entire maintenance period is about 2×300×14=8400 yuan (calculated based on a 14-day maintenance period and 2 maintenance personnel). However, when using the grouting material of the present invention, since it can bear pressure after final setting and does not require maintenance, this labor cost can be completely saved. In large-scale building foundation grouting projects, the maintenance labor cost may be higher, and the cost savings will be more considerable. This directly reduces the labor expenses during the construction process and improves the economic benefits of the project.

[0034] (2) Reduction of equipment rental costs: During the maintenance period, in order to ensure the suitability of the maintenance environment, it is often necessary to rent some special equipment, such as spray equipment for maintaining humidity, heating equipment for maintaining temperature in a low temperature environment, etc. In some grouting projects constructed in the northern winter, it is necessary to rent heating equipment to ensure the maintenance temperature. The daily rental cost of a medium-sized heating equipment is about 500 yuan. If the maintenance period is 10 days, the rental cost of the heating equipment alone will reach 500×10=5000 yuan. After using the grouting material of the present invention, these equipment rental costs can be avoided, which greatly reduces the equipment rental cost of the project and enables the project funds to be more reasonably allocated to other key links.

[0035] (3) Improved comprehensive benefits brought about by shortened construction period: Saving maintenance time can significantly shorten the overall construction period. In urban subway construction, every day of shortened construction time can reduce the impact of construction congestion on urban traffic by one day, indirectly reducing the cost of traffic diversion. At the same time, it can also be put into operation one day earlier, bringing considerable operating income. Taking a subway line as an example, the daily traffic diversion cost during construction may be as high as tens of thousands of yuan, and the income from operating one day earlier is also considerable. In addition, the shortened construction period also means that the next engineering project can be undertaken more quickly, improving the business turnover rate and profitability of the construction company. From this perspective, the comprehensive benefits brought about by the saving of maintenance time by the present invention are multifaceted and have an important role in promoting the development of the engineering construction industry.

[0036] (4) Reduce the rework cost caused by improper maintenance: During the maintenance process of traditional grouting materials, if the maintenance effect is poor due to environmental factors (such as sudden cooling, rainfall) or human factors (untimely maintenance, improper maintenance methods), problems such as substandard material strength and cracking may occur, and rework is required. Rework not only requires reinvestment in materials, manpower and equipment, but also further delays the construction period. In a bridge foundation grouting project, the strength of some areas was insufficient due to improper maintenance, and the rework cost was as high as hundreds of thousands of yuan. The early strength agent of the present invention does not require maintenance, which fundamentally avoids the risk of rework caused by maintenance problems. This is also a major advantage in engineering cost control.

[0037] 3. Economical and applicable: It uses widely available raw materials, has an economical and reasonable formula, and has the potential for industrial promotion.

[0038] In view of the above problems of current geopolymer grouting materials, a quick-setting ultra-high-strength geotechnical polymer grouting material has been developed.

[0039] The material has the following requirements:

[0040] 1. The strength of geotechnical polymer after final setting is required to quickly reach the road traffic requirements, with a 2-hour compressive strength of ≥5MPa, so that it can be opened to traffic directly without maintenance;

[0041] 2. The later strength is required to be very high, and the bearing capacity of the road base can be effectively improved with a small amount of material;

[0042] 3. Requires higher flexural strength, 3-day flexural strength ≥5MPa;

[0043] 4. The slurry is required to have good fluidity and be able to penetrate into the gaps and holes of the road base under pressure;

[0044] 5. The material quality must be stable and environmentally friendly. DETAILED DESCRIPTION

[0045] The following is further described in detail through specific implementation methods:

[0046] Embodiment 1:

[0047] Weigh 52 parts by weight of silicate clinker, 15 parts of alumina clinker, 10 parts of gypsum, 5 parts of silicon powder, 10 parts of mineral powder and 8 parts of fly ash, grind for 15 minutes at 200 rad / min to obtain ball-milled powder. Then weigh 4 parts by weight of water-reducing polycarboxylic acid, 2 parts of collapse-retaining polycarboxylic acid, 1 part of early strength agent, 0.5 parts of retarder, 0.4 parts of thickener and 0.2 parts of defoamer, mix, and stir for 15 minutes at 1200 rad / min, then add 1000 parts of ball-milled powder, stir for 10 minutes at 500 rad / min to obtain fast-setting ultra-high-strength geotechnical polymer grouting material, add water to the obtained grouting material according to a water-cement ratio of 0.32, and stir at a high speed of 15.0 m / s to 20.0 m / s for 3 minutes to obtain slurry.

[0048] Example 2

[0049] Weigh 59 parts by weight of silicate clinker, 5 parts of alumina clinker, 6 parts of gypsum, 5 parts of silicon powder, 15 parts of mineral powder and 10 parts of fly ash, grind at 300 rad / min for 18 minutes to obtain ball-milled powder. Then weigh 3 parts by weight of water-reducing polycarboxylic acid, 1 part of collapse-retaining polycarboxylic acid, 1 part of early strength agent, 0.3 parts of retarder, 0.4 parts of thickener and 0.2 parts of defoamer, mix and stir at 1300 rad / min for 18 minutes, then add 1000 parts of ball-milled powder, stir at 600 rad / min for 12 minutes to obtain fast-setting ultra-high-strength geotechnical polymer grouting material, add water to the obtained grouting material according to a water-cement ratio of 0.32, and stir at a high speed of 15.0 m / s to 20.0 m / s for 3 minutes to obtain slurry.

[0050] The early strength agent is composed of the following components: sodium sulfate, calcium chloride, triethanolamine, citric acid, nano-silicon, and sodium silicate. The formula of the early strength agent combines early strength improvement, fluidity optimization, and later performance enhancement. It is suitable for high-performance concrete and grouting materials, meeting the requirements of rapid construction and long-term durability.

[0051] The slurries of Examples 1 and 2 were prepared into test pieces according to the standard GB / T17671, and the corresponding indicators were tested. The test results are shown in Appendix 1.

[0052] Appendix 1 Performance test results of two types of quick-setting ultra-high strength geotechnical polymer grouting materials

[0053]

[0054] From the above experimental data, it can be concluded that:

[0055] Early strength and fast setting: high strength is achieved in a short time, especially the 2-hour compressive strength is better than traditional geopolymer materials.

[0056] High late strength: The 28-day strength reaches 65.2-93.4MPa, which is significantly higher than common materials on the market.

[0057] Fluidity and stability: The material has high initial fluidity, which is suitable for pressure grouting environment, and has good volume stability after molding.

[0058] Environmental protection and safety: Using industrial by-products (fly ash, slag) as the main ingredients reduces the use of alkali and improves environmental protection and safety.

[0059] Comparison between Example 1 and Example 2:

[0060] (I) Fluidity

[0061] Initial fluidity: The initial fluidity of Example 1 is 18S, while that of Example 2 is 12S. This indicates that the slurry of Example 2 has better fluidity in the initial state, and may be able to be filled into the target area more quickly at the initial stage of pouring, thereby reducing resistance at the initial stage of construction and improving construction efficiency. For example, in some projects with high requirements for pouring speed, the material of Example 2 may have more advantages.

[0062] Fluidity changes over time: The fluidity of Example 1 rises to 20S at 15 minutes, indicating that its fluidity is enhanced in a short time; the fluidity of Example 2 is 14S at 30 minutes, which is lower than the initial value. This reflects that the fluidity of the two materials has different time-varying characteristics. Example 1 may be more suitable for construction scenarios that require increased fluidity within a certain period of time to ensure sufficient filling, while the initial fluidity advantage of Example 2 may gradually weaken over time, making it more suitable for situations with shorter construction time.

[0063] (ii) Setting time

[0064] Initial setting time: Example 1 does not give the initial setting time, while Example 2 has an initial setting time of 300 min. This shows that the setting process of Example 2 starts later, giving construction workers more time to perform operations such as mixing, transportation, and pouring, thereby reducing the risk of premature setting of materials due to tight construction time and affecting construction quality.

[0065] Final setting time: The final setting time of Example 1 is 55 minutes, and that of Example 2 is 350 minutes. Example 1 has a rapid final setting and can reach a certain strength in a short time, and is suitable for projects with extremely strict requirements on the construction period and requiring rapid hardening, such as road repairs, etc.; while Example 2 has a long final setting time, and is more advantageous in some projects that do not require high early strength but need to maintain plasticity for a long time, such as continuous pouring of large foundations.

[0066] (III) Compressive strength

[0067] Early compressive strength: The 2h compressive strength of Example 1 is 6.5 MPa, and this data is not given in Example 2. This shows that Example 1 has a certain strength at an ultra-early stage and can withstand a certain load in a short period of time. For some projects that need to quickly restore the use function, such as temporary repair of airport runways, the material of Example 1 can meet the requirements of rapid load bearing.

[0068] Later compressive strength: From the compressive strength data of 1d, 7d and 28d, Example 2 is higher than Example 1. This shows that the material of Example 2 has great potential for later strength development. In projects with long-term load-bearing and high structural strength requirements, such as foundation projects of high-rise buildings, the material of Example 2 can better ensure the stability and safety of the structure.

[0069] (IV) Flexural strength

[0070] Flexural strength at different ages: Whether it is 1d or 7d flexural strength, Example 2 is higher than Example 1. Flexural strength reflects the ability of a material to resist bending damage. The higher flexural strength of Example 2 means that it performs better when subjected to bending loads, and can be applied to structures that are susceptible to bending stress, such as bridges and pavements, to reduce the risk of cracks and structural damage.

[0071] (V) Diversified Control of Material Properties

[0072] As can be seen from the data, these two embodiments demonstrate the ability to diversify and regulate material properties. In traditional materials, it is often difficult to achieve high fluidity and ultra-early strength at the same time, or to ensure early strength while taking into account the continuous growth of later strength. However, this material achieves a differentiated combination of different performance indicators through a unique formula and process. For example, Example 1 has high ultra-early strength and can increase fluidity within a certain period of time, while Example 2 performs well in later strength and flexural resistance. This diversified performance regulation provides accurate material selection for different engineering needs.

[0073] (VI) Meeting special engineering needs

[0074] Rapid construction requirements: For some disaster relief, emergency repair and other projects, the material needs to be able to set quickly and reach a certain strength. The ultra-early strength and relatively fast setting time of Example 1 meet such requirements. In some large-scale infrastructure construction, the construction process is complicated and time-consuming. The long setting time and high late strength of Example 2 provide guarantees for the smooth progress and long-term stability of the project. This precise adaptation to the needs of different special projects is an important manifestation of innovation.

[0075] Complex stress environment requirements: In actual engineering, structures are often subjected to multiple stresses, such as bending stress, compressive stress, etc. The higher flexural strength of Example 2 enables it to better adapt to environments susceptible to bending stress. Compared with traditional materials, it has more advantages in resisting crack generation and structural damage, expanding the application range of the material.

[0076] (VII) Breaking through traditional performance limitations

[0077] Traditional grouting materials have certain limitations in performance such as fluidity, setting time and strength development, and it is difficult to achieve excellent performance in multiple performance indicators at the same time. The present invention breaks through these traditional limitations through innovative technical means. For example, ultra-early strength can be achieved while ensuring high fluidity, or high late strength and flexural strength can be obtained under long setting time. This breakthrough in traditional performance limitations is the core of its creativity, bringing new ideas and methods to the fields of materials science and engineering applications.

[0078] The following are some examples of application scenarios to illustrate the comprehensive benefits of the invention in shortening the construction period:

[0079] Municipal engineering: Taking the construction of urban subway tunnels as an example, after the grouting construction of each section of the tunnel is completed, the traditional grouting material needs to undergo a 7-14 day curing period to ensure that it reaches sufficient strength to withstand the pressure of subsequent construction. During this period, subsequent lining installation, track laying and other work all need to be suspended and waited. The grouting material of the present invention can bear pressure after final setting, directly eliminating the maintenance waiting time. Assuming that a subway line contains 50 such grouting construction sections, each construction section takes an average of 1 day. When using traditional materials, the curing period alone requires a total of 350-700 days (calculated by taking the median value of the curing period of 525 days). These 525 days of curing time can be saved, greatly shortening the entire subway construction period. This can not only allow the subway to be put into operation ahead of schedule and provide convenient transportation services for urban residents, but also reduce the long-term interference of construction on urban transportation and commercial activities, and reduce social costs.

[0080] Construction project: In the foundation construction of high-rise buildings, after the pile foundation grouting operation is completed, the curing period of traditional grouting materials will affect the construction progress of the subsequent main structure. Generally speaking, the curing period after the foundation grouting of a high-rise building is 7-10 days. If a 30-story high-rise building has an average construction period of 5 days per floor, after the foundation construction is completed, the time waiting for the grouting material to be cured is equivalent to delaying the construction progress of 1-2 floors. The use of the grouting material of the present invention can enable the subsequent construction link to be entered immediately after the foundation grouting, and the saved curing time can allow the construction of the main structure of the building to be carried out in advance. This means that the building can be completed and delivered faster, and the developer can realize capital recovery earlier, while also reducing the costs of equipment rental, personnel management, etc. during the construction process.

[0081] Water conservancy project: The dam grouting reinforcement project of a large water conservancy hub has extremely high requirements for the construction period, because the construction often needs to be carried out during a specific dry season. The maintenance period of traditional grouting materials may occupy a large amount of time during the dry season, increasing the construction risk. For example, in a dam grouting reinforcement project, the dry season lasts for 60 days, and the maintenance period of traditional grouting materials requires 10-15 days (calculated as 12 days). If traditional materials are used, the actual time available for grouting construction and other key processes is only 48 days. Once an unexpected situation occurs during the construction process, the project may not be completed during the dry season, resulting in a one-year extension of the project, which will not only increase the project cost, but also affect the normal maintenance of the dam and the scheduling of water conservancy facilities. The grouting material of the present invention does not require maintenance time, and the effective construction time can be increased to 60 days, which greatly improves the degree of guarantee for the project to be completed on time and reduces the potential losses caused by delays in the construction period.

[0082] Traffic engineering: In the emergency repair project of roads and bridges, time is efficiency. When a bridge needs emergency repair due to an accident, the maintenance period of traditional grouting materials will seriously affect the time it takes to resume traffic on the road. For example, a bridge on a city's main road is damaged and needs to be repaired by grouting reinforcement. If traditional grouting materials are used, a 7-day maintenance period is required after the repair before traffic can be opened. During this period, traffic congestion will occur on surrounding roads, causing great inconvenience to citizens' travel and urban economic activities. It is estimated that the economic losses caused by daily traffic congestion can reach hundreds of thousands of yuan. When the grouting material of the present invention is used, the bridge can withstand pressure after final setting after grouting repair, and traffic can be restored in a short time, avoiding the huge economic losses caused by traffic congestion. It also reflects its unique value in emergency engineering.

[0083] The above is only an embodiment of the present invention, and the common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the present invention.

Claims

1. A quick-setting ultra-high-strength geotechnical polymer grouting material, characterized in that: The method is composed of ball-milled powder and additives, wherein the ball-milled powder includes: 50 to 60 parts of silicate clinker; 5-15 parts of alumina clinker; 5-10 parts of gypsum; Silica powder 5-8 parts; 8~10 parts of mineral powder; 8~10 parts of fly ash.

2. The quick-setting ultra-high-strength geotechnical polymer grouting material according to claim 1 is characterized in that: The mass ratio of the ball-milled powder to the additives is: every 1000 parts of the ball-milled powder includes the following additives: 2-4 parts of water-reducing polycarboxylic acid; 1-2 parts of collapse-resistant polycarboxylic acid; 1~1.5 parts of early strength agent; Retarder 0.5~0.8 parts; Thickener 0.4~0.6 parts; Defoaming agent 0.2~0.3 parts.

3. The quick-setting ultra-high-strength geotechnical polymer grouting material according to claim 1 or 2, characterized in that: The early strength agent is an alkaline seed accelerator.

4. The quick-setting ultra-high-strength geotechnical polymer grouting material according to claim 3, characterized in that: The specific surface area of ​​ball mill powder is 300~400m² / kg.

5. A method for preparing a quick-setting ultra-high-strength geotechnical polymer grouting material, comprising the following steps: (1) Preparation of ball mill powder: adding silicate clinker, alumina clinker, gypsum, silica powder, mineral powder and fly ash into a ball mill according to the proportion and stirring. The speed of the ball mill is 200-300 rad / min and the grinding time is 15-20 min. (2) Preparation of additives: Add water-reducing polycarboxylic acid and collapse-retaining polycarboxylic acid in proportion, adjust the speed of the ball mill to 600-800 rad / min and stir for 5-8 min; then add early strength agent, retarder, thickener and defoamer in proportion, and stir at 1200-1500 rad / min for 15-20 min; (3) Add the additive obtained in step (2) to the ball-milled powder obtained in step (1), and stir at 500-800 rad / min for 10-15 min to obtain a grouting material.

6. The method for preparing the quick-setting ultra-high-strength geotechnical polymer grouting material according to claim 5, characterized in that: The water-cement ratio of the grouting material is 0.28-0.32.

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