阅读说明：本技术 一种中空锚杆注浆材料外加剂、制备方法及应用 (Hollow anchor rod grouting material additive, preparation method and application ) 是由 马伟斌 邹文浩 付兵先 郭小雄 苑立东 安哲立 张金龙 李尧 马超锋 周壮 赵鹏 于 2020-05-08 设计创作，主要内容包括：本发明提供了一种中空锚杆注浆材料外加剂、制备方法及应用,配方为：快硬组分70-80％、膨胀组分8-15％、活性掺合料6-10％、聚羧酸减水剂1-3％、调凝组分1-3％、有机硅消泡剂0.3-0.4％、悬浮稳定剂0.01-0.02％和触变润滑剂0.02-0.03％。与现有技术相比,本发明外加剂与水泥适应性好,掺入后能显著提高中空锚杆注浆材料的流动性和流动性保持时间,其初始流时≦25秒,30min流时≦35秒；能显著改善浆体泌水情况和提高泵送性能；缩短浆体凝结时间,提高早期和后期强度；补偿浆体塑性阶段和硬化后的收缩。(The invention provides an additive for a grouting material of a hollow anchor rod, a preparation method and application thereof, wherein the formula comprises the following components: 70-80% of quick hardening component, 8-15% of expansion component, 6-10% of active admixture, 1-3% of polycarboxylic acid water reducing agent, 1-3% of coagulation adjusting component, 0.3-0.4% of organic silicon defoaming agent, 0.01-0.02% of suspension stabilizer and 0.02-0.03% of thixotropic lubricant. Compared with the prior art, the additive has good adaptability to cement, can obviously improve the fluidity and the fluidity retention time of the grouting material of the hollow anchor rod after being mixed, and has the initial flow time of less than or equal to 25 seconds and the 30min flow time of less than or equal to 35 seconds; the bleeding condition of the slurry can be obviously improved, and the pumping performance can be improved; the setting time of the slurry is shortened, and the early and later strength is improved; compensating for shrinkage during the slurry plasticity phase and after hardening.)

1. The hollow anchor rod grouting material additive is characterized by comprising the following raw materials in percentage by mass: 70-80% of quick hardening component, 8-15% of expansion component, 6-10% of active admixture, 1-3% of polycarboxylic acid water reducing agent, 1-3% of coagulation adjusting component, 0.3-0.4% of organic silicon defoaming agent, 0.01-0.02% of suspension stabilizer and 0.02-0.03% of thixotropic lubricant.

2. The hollow anchor rod grouting material additive according to claim 1, wherein the quick hardening component is formed by compounding one or more of sulphoaluminate cement clinker powder and hyperaluminate cement clinker powder, and the specific surface area of the two clinker powders is larger than or equal to 350m²/kg。

3. The hollow anchor rod grouting material additive as claimed in claim 1 or 2, wherein the quick hardening component is formed by compounding 90 mass percent of sulphoaluminate cement clinker powder and 10 mass percent of aluminate cement clinker powder.

4. The hollow anchor rod grouting material additive according to claim 1, wherein the expansion component is formed by compounding one or more of a calcium oxide expanding agent, a magnesium oxide expanding agent and a calcium sulphoaluminate expanding agent with an azo compound.

5. The hollow anchor rod grouting material additive according to claim 1 or 4, wherein the expansion component is formed by compounding 98-99% of calcium oxide expanding agent, magnesium oxide expanding agent or calcium sulphoaluminate expanding agent and 1-2% of azodicarbonamide by mass percentage.

6. The hollow anchor rod grouting material additive of claim 1, wherein the active admixture is one or more of micro-bead powder, silica fume or superfine mineral powder.

7. The hollow anchor rod grouting material additive as claimed in claim 1 or 6, wherein the active admixture is formed by compounding 75-80% of micro-bead powder and 20-25% of superfine mineral powder or silica fume in percentage by mass.

8. The hollow anchor rod grouting material additive according to claim 1, wherein the coagulation regulating component is one or more of boric acid, sodium gluconate, tartaric acid or citric acid.

9. The hollow anchor rod grouting material additive of claim 1 or 8, wherein the coagulation regulating component is compounded by 45-55% of sodium gluconate and 45-55% of boric acid, tartaric acid or citric acid according to mass percentage.

10. The hollow anchor rod grouting material admixture according to claim 1, wherein the suspension stabilizer is one or more of biological polysaccharide gums such as hydroxypropyl methyl cellulose ether, welan gum or xanthan gum.

11. The hollow anchor rod grouting material admixture according to claim 1, wherein the thixotropic lubricant is magnesium aluminum silicate.

12. The hollow anchor rod grouting material admixture as claimed in claim 1 or 11, wherein the suspension stabilizer is compounded by 5-10% of hydroxypropyl methyl cellulose ether and 90-95% of welan gum or xanthan gum by mass percentage.

13. A method for preparing the hollow anchor rod grouting material admixture according to any one of claims 1 to 12, which is characterized by comprising the following steps: firstly, stirring the rapid hardening component, the expansion component and the active admixture according to the formula amount, and then adding the rest materials in the formula and stirring to obtain the additive of the grouting material of the hollow anchor rod.

14. The application of the additive for the grouting material of the hollow anchor rod as claimed in any one of claims 1 to 12 is characterized in that the additive is used for the grouting material of the hollow anchor rod, and the specific application method comprises the following steps: and mixing the additive and the cement, wherein the dosage ratio of the additive to the cement is 2: 8.

15. The application method according to claim 14, wherein the application method is as follows: and (3) mixing 20 mass percent of additive and 80 mass percent of cement which is added into common silicate 42.5, adding water accounting for 28 mass percent of the total mass of the additive and the cement, and stirring for 3-5min by using a forced stirrer to obtain slurry for grouting the hollow anchor rod.

Technical Field

The invention belongs to the technical field of materials for geotechnical engineering construction, and particularly relates to an additive for a grouting material of a hollow anchor rod, a preparation method and application.

Background

The hollow anchor rod grouting technology is an anchoring technology suitable for weak surrounding rocks, fault broken zones, sand pebbles and the like, and holes are easy to collapse after hole rotation, the anchor rod and grouting are combined, the anchor rod has the supporting effect of the anchor rod, a grouting pipe and the anchor rod are integrated, the hollow grouting anchor rod can effectively improve the anchoring effect on the surrounding rocks, the injected slurry can fill cracks in the surrounding rocks, and the surrounding rocks with holes form a whole through the bonding effect of the grouting material, so that the capability of bearing deformation of the surrounding rocks is improved.

The grouting materials applied in the current engineering are mainly divided into chemical grouting materials and cement-based grouting materials, and compared with the prior art, the cement-based grouting materials have the advantages of good durability, high strength, no toxicity, wide sources, low cost and the like, and are widely applied to the current engineering. Although the research on grouting materials is mature at home and abroad, few researches on the grouting materials of the hollow anchor rod are carried out at present, so that the grouting materials for the hollow anchor rod in actual engineering are mainly common cement paste. However, the phenomenon of bottom sinking bleeding easily appears as the slip casting material in the cement paste, lead to appearing stifled pipe in the slip casting work progress, influence the construction progress, and the slurry setting time is long, cause the loss of slurry easily in loose country rock region, can't form stable anchor grout blanket, this risk that has also increased the anchor rod hole and has collapsed, intensity increases slowly also leads to the anchor effect to produce time later simultaneously, if the stock disturbance appears or the rock stratum condition that warp during this period, then can't guarantee later stage slip casting material's anchor effect. And the later stage volume shrinkage of the common cement paste is large, and pores are easily generated between the grouting material and the rock stratum, so that the anchor rod is easily damaged by external corrosive substances, and the overall anchoring effect of the anchor rod is reduced. Because the interior of the cement-based grouting material is difficult to detect after grouting is completed, the defects of the common cement-based grouting material after grouting is completed easily cause great potential safety hazards and are difficult to find, and irreparable serious consequences can be caused when problems are found.

If the grouting material is researched again, the selection and experimental verification from the aspects of the mixing proportion and raw materials are needed, and a large amount of manpower and material resources are consumed, so that the research on the modification of the additive suitable for cement paste is a more feasible and effective measure aiming at the existing anchoring grouting technology. Therefore, the additive for the grouting material of the hollow anchor rod, which has wide cement adaptability and can ensure better slurry homogeneity, high early and later strength, micro-expansion and strong anchoring force, is very important.

Disclosure of Invention

The invention aims to provide an additive for a grouting material of a hollow anchor rod, which has the performance meeting the requirements of wide cement adaptability, good slurry homogeneity, high early and later strength, micro-expansion, strong anchoring force and the like.

The invention also aims to provide a preparation method of the additive for the grouting material of the hollow anchor rod.

The invention also aims to provide application of the additive for the grouting material of the hollow anchor rod.

The specific technical scheme of the invention is as follows:

the invention provides an additive for a grouting material of a hollow anchor rod, which comprises the following raw materials in percentage by mass: 70-80% of quick hardening component, 8-15% of expansion component, 6-10% of active admixture, 1-3% of polycarboxylic acid water reducing agent, 1-3% of coagulation adjusting component, 0.3-0.4% of organic silicon defoaming agent, 0.01-0.02% of suspension stabilizer and 0.02-0.03% of thixotropic lubricant.

The sum of the raw materials is 100 percent.

The quick hardening component is formed by compounding one or more of sulphoaluminate cement clinker powder or high-alumina cement clinker, wherein the specific surface area of the two clinker powders is larger than or equal to 350m²/kg。

The rapid hardening component is preferably compounded by 90 mass percent to 10 mass percent of sulphoaluminate cement clinker powder and high-alumina cement clinker powder, and the early performance of the grouting material can be obviously improved by the preferable formula.

The expansion component is formed by compounding one or more of calcium oxide expansion agent, magnesium oxide expansion agent or calcium sulphoaluminate expansion agent with azo compounds.

The expansion component is preferably compounded by 98-99% of calcium oxide expansion agent, magnesium oxide expansion agent or calcium sulphoaluminate expansion agent and 1-2% of azodicarbonamide according to mass percentage. This preferred formulation can compensate for shrinkage during the slurry plasticity phase and after hardening.

The active admixture is one or more of micro-bead powder, silica fume or superfine mineral powder, wherein the specific surface area of the micro-bead powder is not less than 900m²The activity index of/kg and 28d is not less than 90 percent, and SiO in the silica fume₂The content is not less than 85 percent, the 28d activity index is not less than 85 percent, and the specific surface area of the superfine mineral powder is not less than 1000m²The activity index of/kg, 28d is not less than 110%. The slurry pumping performance is improved through the self-rolling effect of the admixture, and the high activity of the admixture can improve the later strength of the slurry.

The active admixture is preferably formed by compounding 75-80% of micro-bead powder and 20-25% of superfine mineral powder or silica fume in percentage by mass.

The water reducing rate of the polycarboxylate superplasticizer mortar is not less than 20%;

the coagulation regulating component is one or more of boric acid, sodium gluconate, tartaric acid or citric acid.

Preferably, the coagulation regulating component is prepared by compounding 45-55% of sodium gluconate and 45-55% of boric acid, tartaric acid or citric acid in percentage by mass. The optimal formula and the quick-hardening components have good adaptability, so that the slurry can be ensured to have sufficient time fluidity on the premise of ensuring the early strength of the slurry, and the grouting construction requirement can be met.

The organic silicon defoaming agent is a ZJ-D120 type polyether modified organic silicon defoaming agent of Jiangsu McAb scientific and technological building materials science and technology Limited company, and the scheme can increase the dispersibility of the water reducing agent and improve the water reducing effect of the water reducing agent while removing harmful bubbles in slurry.

The suspension stabilizer is one or more of biological polysaccharide gums such as hydroxypropyl methyl cellulose ether, welan gum or xanthan gum. The slurry can be improved in homogeneity, the phenomenon of bottom sinking and bleeding is avoided, the probability of pump blockage is reduced, the adsorption of the water reducing agent to cement can be enhanced, and the adaptability of the admixture and the cement is improved.

The suspension stabilizer is preferably compounded by 5-10% of hydroxypropyl methyl cellulose ether and 90-95% of welan gum or xanthan gum by mass percentage.

The thixotropic lubricant is magnesium aluminum silicate, can improve the thixotropy of slurry, can be quickly thickened after the slurry is grouted to form a stable anchoring grouting layer, and can prevent the slurry from losing after the slurry is grouted in a loose surrounding rock area.

The invention provides a preparation method of an additive for a grouting material of a hollow anchor rod, which comprises the following steps:

firstly, stirring the rapid hardening component, the expansion component and the active admixture according to the formula amount, and then adding the rest materials in the formula and stirring to obtain the additive of the grouting material of the hollow anchor rod.

The preferred preparation method is as follows: firstly, stirring the rapid hardening component, the expansion component and the active admixture with the formula amount for 5-10min by using a mixer, then adding the rest materials in the formula and stirring for 5min to obtain the hollow anchor rod grouting material admixture.

The hollow anchor rod grouting material additive is used for a hollow anchor rod grouting material, and the specific application method comprises the following steps:

and mixing the additive with cement, wherein the mass ratio of the additive to the cement is 15-25: 75-85.

The preferred application method is as follows: and (3) mixing 20 mass percent of additive and 80 mass percent of common silicate 42.5 cement, adding 28 mass percent of water of the total mass of the additive and the cement, and stirring for 3-5min by using a forced stirrer to obtain slurry for grouting the hollow anchor rod.

The preparation method is simple, the raw materials are easy to obtain, and the product cost is low.

The invention relates to an additive which is specially developed based on a hollow anchor rod grouting material, and based on the existing anchoring grouting system, the rapid-hardening component and the set-regulating component are adopted to jointly act, so that the slurry setting time is greatly shortened on the premise of meeting the construction time requirement, the anchoring effect time of the slurry is advanced, the problems of collapse or shrinkage and the like in the early stage of an anchor rod hole are avoided, and the influence of early anchor rod disturbance or rock stratum deformation on the anchoring force can be weakened. The suspension stabilizer can ensure that the slurry does not have the phenomenon of bottom sinking and bleeding, and the pumping performance of the slurry is improved through the ball effect of the active admixture, so that the construction efficiency of grouting is improved, the adsorptivity of the water reducing agent to cement is enhanced, the adaptability of the admixture and the cement is increased, and the high activity of the active admixture can also improve the later strength of the slurry. Aiming at a weak surrounding rock area, thixotropic lubricity is introduced to increase thixotropy of slurry, after grouting of the slurry is completed, the slurry can be thickened rapidly due to the thixotropy to form a stable wedge-shaped anchoring body, and loss of the slurry from a surrounding rock gap is avoided to a great extent. The introduction of the expansion component can compensate the contraction generated in the slurry plasticity stage and after hardening, and the volume stability of the slurry is improved. The invention is mixed into the hollow anchor rod grouting material, can ensure that the slurry has no bleeding stratification phenomenon, improves the early strength of the slurry on the premise of ensuring the construction time of the slurry, and has micro-expansion of the volume of the slurry and high later strength and anchoring strength.

Compared with the prior art, the invention has the following advantages:

1. the additive has good adaptability to cement, can obviously improve the fluidity and the fluidity retention time of the grouting material of the hollow anchor rod after being mixed, and has the initial flow time of less than or equal to 25 seconds and the 30min flow time of less than or equal to 35 seconds.

2. After the grouting material for the hollow anchor rod is doped, the bleeding condition of slurry can be obviously improved, the pumping performance is improved, the bleeding rate is less than or equal to 0.2%, and the grouting construction efficiency is improved.

3. After the hollow anchor rod grouting material is doped, the slurry coagulation time can be shortened, and the early and later strength can be improved, wherein the 2h strength is not less than 10MPa, the 1d strength is not less than 30MPa, and the 28d strength is not less than 75 MPa.

4. After the hollow anchor rod grouting material is doped into the hollow anchor rod grouting material, the plastic stage and the hardened shrinkage of slurry can be compensated, and the 3-hour vertical expansion rate is larger than or equal to 0.03%, the 24-hour vertical expansion rate is larger than or equal to 0.05%, and the 7-d limited expansion rate is larger than or equal to 0.02%.

Detailed Description

The present invention will be further described with reference to the following examples, but the present invention is not limited to the following examples.