High-strength and high-temperature-resistant cement-based grouting material and preparation method thereof

Abstract

The application discloses a kind of high-strength high-temperature-resistant cement-based grouting material, each component and the mass percentage it occupies include: cement 12~40%, mineral powder 1~17%, microbead powder 1~10%, aggregate 30~60%, fiber 0.5~1.0%, anti-settling-keeping-bleeding composite modifier 0.01~0.03%, water reducing agent 0.10~0.25%, early expansion agent 0~0.03%, defoaming agent 0~1.0%; Water material ratio is 0.12~0.14, wherein the anti-settling-keeping-bleeding composite modifier is intercalation modified brunei gum.The application uses cement, mineral powder and microbead powder as main cementing component, combined with high-temperature-resistant aggregate and fiber and anti-settling-keeping-bleeding composite modifier and other functional components, the obtained grouting material has higher high-temperature-resistant capacity, compressive strength ratio and thermal shock stability, and has better working performance and higher compressive strength, wide applicability.

Description

Technical Field

[0001] The invention belongs to the technical field of building materials, and particularly relates to a high-strength and high-temperature resistant cement-based grouting material and a preparation method thereof. Background Art

[0002] Cement-based grouting materials, due to their early strength, minimal expansion, and excellent workability, are widely used in projects such as secondary grouting of equipment foundations, anchor bolt anchoring, and building structure reinforcement. Existing grouting materials typically focus on properties such as fluidity, strength, and expansion rate, without researching and improving thermal shock resistance. Inadequate compressive strength ratios and thermal shock resistance in high-temperature environments are the main factors hindering the widespread application of cement-based grouting materials in high-temperature environments.

[0003] Patent application CN107244858A discloses a high-temperature resistant grouting material, which is made from the following raw materials in parts by weight: 100 parts of cement, 120-130 parts of quartz sand, 50-60 parts of fly ash, 15-16 parts of silica fume, 4-7 parts of titanium boride, 12-14 parts of carbon fiber, 20-25 parts of steel fiber, 5-8 parts of expansion agent, 1-3 parts of water reducer, 1-2 parts of defoamer, 2-5 parts of antifreeze, 0.5-1.5 parts of early strength agent, and 0.5-0.8 parts of retarder; it has the characteristics of high strength, long service life, and the ability to withstand high temperatures above 1000°C; but it does not involve modification of the thermal shock stability of the grouting material, cannot adapt to rapid changes in the operating environment temperature, and the resulting grouting material has poor fluidity. Summary of the Invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the main purpose of the present invention is to provide a high-strength and high-temperature resistant cement-based grouting material and a preparation method thereof. The grouting material has high high-temperature resistance, compressive strength ratio and thermal shock stability, and has good working performance and high compressive strength.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A high-strength and high-temperature resistant cement-based grouting material, wherein the components and their mass percentages include: 12-40% cement, 1-17% mineral powder, 1-10% microbead powder, 30-60% aggregate, 0.5-1.0% fiber, 0.01-0.03% anti-settling-slump-preserving composite modifier, 0.10-0.25% water reducer, 0-0.03% early expansion agent, and 0-1.0% defoaming agent; the water-to-material ratio is 0.12-0.14, wherein the anti-settling-slump-preserving composite modifier is intercalated modified Brunei rubber.

[0007] In the above solution, the intercalation-modified Brunei rubber is attapulgite intercalation-modified Brunei rubber.

[0008] Furthermore, the preparation method of the anti-settling-collapse-preserving composite modifier is: adding attapulgite to a Brunei glue aqueous solution, carrying out a water bath reaction under a protective atmosphere and stirring conditions, centrifuging, washing, filtering, and drying to obtain the anti-settling-collapse-preserving composite modifier.

[0009] In the above solution, the particle size of the attapulgite is 400-600 mesh.

[0010] In the above solution, the concentration of the Brunei glue solution is 0.08-0.12 wt%.

[0011] In the above scheme, the solid-to-liquid ratio of the attapulgite to the Brunei glue aqueous solution is 1g:40-60mL.

[0012] In the above solution, the protective atmosphere can be nitrogen or argon.

[0013] In the above scheme, the temperature of the water bath reaction is 70-80° C. and the reaction time is 22-26 h.

[0014] In the above scheme, the temperature used in the drying step is 60-70° C. and the time is 6-12 hours.

[0015] In the above solution, the cement is one or more of Portland cement, ordinary Portland cement, and sulphoaluminate cement, and the strength grade is above 52.5.

[0016] In the above scheme, the mineral powder is one or more of S95 mineral powder or ultrafine mineral powder; the specific surface area of ​​S95 mineral powder is 300-500m 2 / kg, the specific surface area of ​​ultrafine mineral powder is 600~1000m 2 / kg.

[0017] In the above scheme, the microbead powder is fly ash extract, and its bulk density is ≥700kg / m 3 , silicon dioxide content ≥50%.

[0018] In the above solution, the aggregate includes high-aluminum aggregate, and the content of the high-aluminum aggregate is above 20wt%.

[0019] Furthermore, the particle size of the high-alumina aggregate is 0-1 mm.

[0020] Furthermore, the aggregate further comprises one or more of quartz sand with a mesh size of 40 to 70 and quartz sand with a mesh size of 20 to 40.

[0021] In the scheme, the fiber is one or more of polyethylene fiber with an average diameter of 0.02-0.04 mm, polypropylene fiber with an average diameter of 0.02-0.04 mm, basalt fiber with an average diameter of 0.01-0.03 mm, and steel fiber with an average diameter of 0.18-0.22 mm, and the average length of the fiber is 6-10 mm.

[0022] In the scheme, the water reducing agent is a powder polycarboxylic acid water reducing agent, and the water reducing rate of the mortar is greater than or equal to 20%.

[0023] In the scheme, the early expansion agent is an azo expansion agent.

[0024] Further, the azo expansion agent can be azodicarbonamide or azobisisobutyronitrile, etc.

[0025] In the scheme, the defoaming agent is a polyether-modified silicone defoaming agent.

[0026] The preparation method of the high-strength and high-temperature-resistant cement-based grouting material includes the following steps:

[0027] 1) Raw material weighing, the mass percentage of each component and the mass percentage thereof include: cement 12-40%, mineral powder 1-17%, microbead powder 1-10%, aggregate 30-60%, fiber 0.5-1.0%, anti-settling and slump-keeping composite modifier 0.01-0.03%, water reducing agent 0.10-0.25%, early expansion agent 0-0.03%, and defoaming agent 0-1.0%;

[0028] 2) After the weighed raw materials are mixed, a high-strength and high-temperature-resistant cement-based grouting material premix is obtained;

[0029] 3) After the premix and water are mixed and stirred uniformly at a water-material ratio of 0.12-0.14, a high-strength and high-temperature-resistant cement-based grouting material is obtained.

[0030] The principle of the application is:

[0031] A large amount of mineral admixtures such as mineral powder and microbeads can be introduced into the high-strength, high-temperature-resistant cement-based grouting of the present invention, which can greatly improve the residual strength of the mineral admixture at high temperatures, improve the working performance of the grouting material, and make the grouting material easier to construct. Among the introduced fibers, polyethylene fiber has the characteristics of low density, high strength, chemical corrosion resistance, high temperature resistance, and low elongation at break. It can be evenly dispersed in the grouting material and can improve the high-temperature mechanical properties of the grouting material. Under high temperatures of 200-300°C, it can act as a sacrificial material to provide interconnecting holes, prevent the expansion stress and bursting of water vapor in the capillaries at high temperatures, and prevent the internal stress accumulation caused by the inconsistent thermal expansion coefficients of aggregate and cement stone at high temperatures. Therefore, it can particularly improve the thermal shock stability of the grouting material. Basalt fiber has good high-temperature resistance and can withstand temperatures above 1400°C, which can prevent cement-based materials from bursting at ultra-high temperatures.

[0032] The early expansion agent introduced can improve the expansion performance of the grouting material in the plastic stage, so that the grouting material can play a role of micro-expansion during application, improve the tightness of the bonding between the grouting material and the equipment foundation, and improve the application effect.

[0033] The high-strength and high-temperature resistant grouting material of the present invention is added with a high-performance water reducer and a defoamer and is combined with high-temperature resistant aggregates. The gradation is reasonable, and the good working performance of the obtained grouting material is ensured.

[0034] The present invention utilizes a high-aluminum aggregate-based aggregate system, using high-aluminum aggregate as a high-temperature-resistant aggregate. On the one hand, high-aluminum aggregate has a high-temperature resistance of up to 1500°C, significantly improving the high-temperature resistance of the grouting material. On the other hand, high-aluminum aggregate inherently possesses high strength, is porous, and has a rough surface, which can improve the bonding between the slurry and the aggregate, thereby significantly increasing the compressive strength of the grouting material. However, due to its high water absorption and high apparent density, high-aluminum aggregates can easily settle and experience significant fluidity loss in high-fluidity systems such as grouting materials.

[0035] In view of the above technical problems, the present application further adopts attapulgite intercalation modified Brunei gum as an anti-settling and slump-preserving composite modifier, which can effectively improve the adverse effects of aggregates and traditional thickeners on the working performance, and the working principle is as follows: since the Brunei gum molecules have a large anionic charge density, they have a strong complexation with calcium ions on the surface of cement particles, and the adsorption effect on the surface of cement particles is stronger than that of polycarboxylic acid water reducing agent molecules, which is easy to cause competitive adsorption effect with polycarboxylic acid water reducing agent, and the dispersion effect of water reducing agent on cement particles is significantly weakened, resulting in poor working performance; after the original Brunei gum is modified by intercalation method using attapulgite, the slow release effect of Brunei gum components can be realized, and the three-dimensional network structure of Brunei gum aqueous solution is not changed, thereby improving the compatibility between Brunei gum and other additives, etc. The competitive adsorption effect of Brunei gum and polycarboxylic acid water reducing agent can be effectively improved, and the self-thickening and anti-segregation and delamination effects of Brunei gum are not obviously affected; and the incorporation of attapulgite can promote the secondary hydration of cement, consume calcium hydroxide to generate more C-S-H gel to harden the cement paste, reduce cracks and large pores, and improve the compactness of the structure, thereby significantly improving the high temperature performance of the grouting material.

[0036] Compared with the prior art, the present application has the following advantages:

[0037] 1) The present application uses cement, mineral powder and microsphere powder as main cementitious components, combined with high-temperature-resistant aggregates and fibers, etc., which can effectively improve the mechanical properties and high-temperature-resistant performance of the obtained grouting material;

[0038] 2) The present application uses attapulgite intercalation modified Brunei gum as an anti-settling and slump-preserving composite modifier, which can effectively improve the problems of easy settling and large loss of fluidity caused by aggregates and traditional thickeners, etc., and ensure the working performance of the obtained grouting material; at the same time, it can improve the compactness of the structure and further improve the high-temperature-resistant performance of the grouting material;

[0039] 3) The high-strength and high-temperature-resistant grouting material of the present application has a 28d compressive strength of more than 90MPa under standard curing conditions, which can meet the strength requirements of most grouting construction, and some are higher than 120MPa, which can be used as high-temperature-resistant and ultra-high-strength grouting material with special operation requirements, and has wide applicability. DETAILED DESCRIPTION

[0040] The present application will be further described below in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0041] The preparation method of the anti-settling and slump-keeping composite modifier used in the following examples includes the following steps: 5 g of attapulgite is weighed and added into 250 mL of a 0.1 wt% aqueous solution of raw Brunei gum, and then the mixture is reacted under the conditions of N2 atmosphere, stirring and 75°C water bath for 24 h. The product is separated by centrifugation, washed with deionized water, filtered, and dried in vacuum at 65°C for 6-12 h to obtain the anti-settling and slump-keeping composite modifier.

[0042] In the following examples, the water reducing agent used is a powder polycarboxylic acid water reducing agent, and the mortar water reducing rate is 30%; the early expansion agent used is azodicarbonamide.

[0043] The defoaming agent used is a polyether-modified silicone defoaming agent P803 provided by Mingling Chemical Industry Co., Ltd.

[0044] Example 1

[0045] A high-strength and high-temperature-resistant cement-based grouting material, the preparation materials and the mass percentage thereof include: cement 24.98%, mineral powder 15.7%, microbead powder 4%, aggregate 55%, fiber 0.05%, anti-settling and slump-keeping composite modifier 0.02%, water reducing agent 0.18%, early expansion agent 0.02%, defoaming agent 0.05%, and water-material ratio 0.13; wherein the cement is ordinary portland cement with a strength grade of 52.5; the mineral powder is S95 mineral powder; the fiber includes polypropylene fiber with a length of 6 mm and an average diameter of 0.02 mm, and basalt fiber with a length of 8 mm and an average diameter of 0.02 mm (mass ratio of 1:1); and the aggregate is 0-1 mm high-aluminum aggregate.

[0046] The preparation method thereof includes the following steps:

[0047] 1) Raw material weighing, the above-mentioned raw materials are weighed according to the proportion;

[0048] 2) After the weighed components are fully mixed, a high-strength and high-temperature-resistant cement-based grouting material premix is obtained;

[0049] 3) The premix and water are mixed and stirred uniformly according to a water-material ratio of 0.13 to obtain a high-strength and high-temperature-resistant cement-based grouting material premix.

[0050] Example 2

[0051] A high-strength, high-temperature-resistant cement-based grouting material, the preparation method of which is substantially the same as that of Example 1, except that: the preparation materials and their mass percentages include: cement, mineral powder, microbead powder, aggregate, fiber, anti-settling-collapse composite modifier, water reducer, early expansion agent, and defoamer are 40.98%, 8.64%, 5%, 45%, 0.05%, 0.02%, 0.24%, 0.02%, and 0.05%, respectively; the water-to-material ratio is 0.13; wherein The cement comprises ordinary Portland cement (95wt%) with a strength grade of 52.5 and sulfoaluminum cement (5wt%), the mineral powder is S95 mineral powder, the fibers comprise polypropylene fibers with an average length of 6mm and basalt fibers with an average length of 8mm (the mass ratio of the two is 1:1); the aggregate consists of 0-1mm high-alumina aggregate (40.0wt%), 30-50 mesh quartz sand (33.3wt%) and 40-70 day quartz sand (26.7wt%).

[0052] Example 3

[0053] A high-strength, high-temperature-resistant cement-based grouting material, the preparation method of which is substantially the same as that of Example 1, except that: the preparation materials and their mass percentages include: 24.98% cement, 15.7% mineral powder, 4% microbead powder, 55% aggregate, 0.05% fiber, 0.02% anti-settling-collapse composite modifier, 0.18% water reducer, 0.02% early expansion agent, and 0.05% defoamer; the water-to-material ratio is 0.13; wherein the cement is ordinary Portland cement with a strength grade of 52.5, the mineral powder is ultrafine mineral powder, and the fiber is polypropylene fiber with an average length of 6 mm and an average diameter of 0.02 mm; the aggregate is composed of 0-1 mm high-alumina aggregate (40.0 wt%), 30-50 mesh quartz sand (21.6 wt%), and 40-70 day quartz sand (38.4 wt%).

[0054] Comparative Example 1

[0055] A grouting material, the preparation method of which is substantially the same as that of Example 1, except that: the preparation materials and their mass percentages include: 24.98% cement, 15.7% mineral powder, 4% microbead powder, 55% aggregate, 0.05% fiber, 0.02% thickener (400 viscosity hydroxypropyl methylcellulose HPMC), 0.02% water reducer, 0.18% early expansion agent, 0.02% defoamer, and a water-to-material ratio of 0.13; wherein, the cement is ordinary Portland cement with a strength grade of 52.5, the mineral powder is S95 mineral powder, the fibers include polypropylene fibers with a length of 6 mm and an average diameter of 0.02 mm and basalt fibers with a length of 8 mm and an average diameter of 0.02 mm (the mass ratio of the two is 1:1), the early expansion agent is an azo compound; and the aggregate is 0-1 mm high-aluminum aggregate.

[0056] Comparative Example 2

[0057] A grouting material, the preparation method of which is substantially the same as that of Example 1, except that: the preparation materials and their mass percentages include: 24.98% cement, 15.7% mineral powder, 4% microbead powder, 55% aggregate, 0.05% fiber, 0.001% Brunei rubber, 0.019% attapulgite, 0.18% water reducer, 0.02% early expansion agent, 0.05% defoamer, and a water-to-material ratio of 0.13; wherein the cement is ordinary Portland cement with a strength grade of 52.5, the mineral powder is S95 mineral powder, the fibers include polypropylene fibers with an average length of 6 mm and an average diameter of 0.02 mm and basalt fibers with an average length of 8 mm and an average diameter of 0.02 mm (the mass ratio of the two is 1:1), the early expansion agent is an azo compound; and the aggregate is 0-1 mm high-aluminum aggregate.

[0058] The high-temperature resistant cement-based grouting materials obtained in Examples 1 to 3 and Comparative Examples 1 to 2 were subjected to performance tests in accordance with the Technical Specification for Application of Cement-Based Grouting Materials (GB / T 50448-2015) and the Technical Specification for Application of Heat-Resistant Concrete (YB / T 4252-2011), respectively. The results are shown in Table 1.

[0059] Table 1 Performance test results of cement-based grouting materials obtained in Examples 1 to 3 and Comparative Examples 1 to 2

[0060]

[0061]

[0062] Note: “—” indicates that there are no relevant indicator requirements in this standard.

[0063] The present invention is not limited to the above-described embodiments. Persons skilled in the art may make various improvements and modifications without departing from the principles of the present invention, and such improvements and modifications are deemed to be within the scope of protection of the present invention. Any matters not described in detail in this specification constitute prior art known to those skilled in the art.

Claims

1. A high-strength and high-temperature resistant cement-based grouting material, characterized in that: The components and their mass percentages include: 12-40% cement, 1-17% mineral powder, 1-10% microbead powder, 30-60% aggregate, 0.5-1.0% fiber, 0.01-0.03% anti-settling-slump-preserving composite modifier, 0.10-0.25% water reducer, 0-0.03% early expansion agent, and 0-1.0% defoamer; the water-to-material ratio is 0.12-0.14; wherein the anti-settling-slump-preserving composite modifier is intercalated modified Brunei rubber; The preparation method of the anti-settling-collapse-preventing composite modifier comprises the following steps: adding attapulgite into a Brunei glue solution, carrying out a water bath reaction under a protective atmosphere and stirring conditions, centrifuging, washing, filtering, and drying to obtain the anti-settling-collapse-preventing composite modifier.

2. The high-strength and high-temperature resistant cement-based grouting material according to claim 1, characterized in that: The temperature of the water bath reaction is 70-80° C. and the reaction time is 22-26 hours.

3. The high-strength and high-temperature resistant cement-based grouting material according to claim 1, characterized in that: The cement is one or more of Portland cement, ordinary Portland cement, and sulphoaluminate cement; and the strength grade is above 52.

5.

4. The high-strength and high-temperature resistant cement-based grouting material according to claim 1, characterized in that: The mineral powder is one or more of S95 mineral powder or ultrafine mineral powder; the specific surface area of ​​S95 mineral powder is 300~500m 2 / kg, the specific surface area of ​​ultrafine mineral powder is 600~1000m 2 / kg; microbead powder is fly ash extract, and its bulk density is ≥700kg / m 3 , silicon dioxide content ≥50%.

5. The high-strength and high-temperature resistant cement-based grouting material according to claim 1, characterized in that: The aggregate comprises high-aluminum aggregate, wherein the content of the high-aluminum aggregate is greater than 20wt%.

6. The high-strength and high-temperature resistant cement-based grouting material according to claim 1, characterized in that: The fibers are one or more of polyethylene fibers with an average diameter of 0.02-0.04 mm, polypropylene fibers with an average diameter of 0.02-0.04 mm, basalt fibers with an average diameter of 0.01-0.03 mm, and steel fibers with an average diameter of 0.18-0.22 mm; and the average fiber length is 6-10 mm.

7. The high-strength and high-temperature resistant cement-based grouting material according to claim 1, characterized in that: The water reducer is a powdered polycarboxylic acid water reducer, and the mortar water reduction rate is ≥20%; the early expansion agent is an azo expansion agent.

8. The method for preparing the high-strength and high-temperature resistant cement-based grouting material according to any one of claims 1 to 7, characterized in that: The steps include: 1) Weigh the raw materials. The components and their mass percentages include: cement 12-40%, mineral powder 1-17%, microbead powder 1-10%, aggregate 30-60%, fiber 0.5-1.0%, anti-settling-collapse composite modifier 0.01-0.03%, water reducer 0.10-0.25%, early expansion agent 0-0.03%, and defoamer 0-1.0%. 2) Mixing the weighed raw materials to obtain a high-strength and high-temperature resistant cement-based grouting material premix; 3) The premix and water are mixed and stirred evenly at a water-to-material ratio of 0.12 to 0.14 to obtain a high-strength and high-temperature resistant cement-based grouting material.

Images