阅读说明：本技术 一种利用改性火山灰岩粉制备的超高性能混凝土 (Ultrahigh-performance concrete prepared from modified volcanic ash rock powder ) 是由 马跃飞 高明星 张皓 孙振平 冀言亮 于 2020-12-31 设计创作，主要内容包括：本发明公开一种利用改性火山灰岩粉制备的超高性能混凝土,包括52.5级硅酸盐水泥、改性火山灰岩粉、矿渣粉、硅灰、偏高岭土、石英砂、聚羧酸系减水剂、硅酸镁、氧化石墨烯、聚羧酸改性纳米C-S-H、水。本发明中利用改性火山灰岩粉增强了超高性能混凝土具有流动性好、强度高以及制备成本低等特点,从而有助于提高本发明制备的超高性能混凝土的知名度以及市场的竞争力。因此,采用本发明制备的超高性能混凝土是一款综合性能高的混凝土。(The invention discloses an ultrahigh-performance concrete prepared from modified volcanic ash rock powder, which comprises 52.5-grade portland cement, modified volcanic ash rock powder, slag powder, silica fume, metakaolin, quartz sand, a polycarboxylic acid water reducing agent, magnesium silicate, graphene oxide, polycarboxylic acid modified nano C-S-H and water. The modified volcanic limestone powder is utilized to enhance the characteristics of good fluidity, high strength, low preparation cost and the like of the ultra-high performance concrete, thereby being beneficial to improving the popularity and the market competitiveness of the ultra-high performance concrete prepared by the invention. Therefore, the ultra-high performance concrete prepared by the invention is a concrete with high comprehensive performance.)

1. The ultrahigh-performance concrete prepared from the modified volcanic ash rock powder is characterized by comprising the following components in parts by weight:

2. the ultra-high performance concrete prepared from the modified volcanic ash rock powder as claimed in claim 1, wherein the surface area of the slag powder is 300-350m²Per kg, water content not more than 1% and loss on ignition not more than 2%.

3. The ultra-high performance concrete prepared from the modified volcanic ash rock powder as claimed in claim 1, wherein the silica fume has an average particle size of 1-3 μm and a bulk weight of 1650-1750kg/m³(ii) a Wherein the mass of the silica fume with the particle size less than 1 μm in the silica fume is 80 percent of the mass of the silica fume.

4. The ultra-high performance concrete prepared by using the modified volcanic ash rock powder as claimed in claim 1, wherein the metakaolin has an activity index of more than 110, a loss on ignition of less than 0.7% and an average particle size of 10-20 μm.

5. The ultra-high performance concrete prepared by using the modified volcanic ash rock powder as claimed in claim 1, wherein the quartz sand is composed of quartz sand with an average particle size of 20-40 meshes, quartz sand with an average particle size of 40-70 meshes and quartz sand with an average particle size of 70-140 meshes in a mass ratio of 6:3: 1.

6. The ultra-high performance concrete prepared from the modified volcanic ash rock powder as claimed in claim 1, wherein the concentration of the graphene oxide is 3.0%, and the average particle size of the carboxylic acid modified nano C-S-H is 40-80 nm.

7. The ultra-high performance concrete prepared from the modified volcanic ash rock powder as claimed in any one of claims 1-6, wherein the modified volcanic ash rock powder is obtained by modifying volcanic ash rock powder with 3mm average particle size by using grinding aid, surfactant and activity activator; wherein the specific surface area of the obtained modified volcanic ash rock powder is 500-550m²/kg。

8. The ultra-high performance concrete prepared by using the modified volcanic ash rock powder as claimed in claim 7, wherein the grinding aid is composed of triethanolamine, ethylene glycol and diethanolamine, the surface modifier is composed of higher fatty acid, titanate and organic chromium, and the active activator is composed of sodium hydroxide and water glass; wherein the triethanolamine, the ethylene glycol, the diethanolamine, the higher fatty acid, the titanate, the organic chromium, the sodium hydroxide, the water glass and the volcanic ash rock powder respectively comprise the following components in parts by weight: 0.01-0.04 part, 0.01-0.03 part, 0.01-0.04 part, 0.02-0.05 part, 2-5 parts, 1-3 parts and 100 parts.

9. The ultra-high performance concrete prepared by using the modified volcanic ash rock powder as claimed in claim 8, wherein the modulus of the water glass is 1; the mass concentration of the sodium hydroxide is 40%.

10. The ultra-high performance concrete prepared from the modified volcanic ash rock powder according to claim 9, wherein the preparation method of the modified volcanic ash rock powder comprises the following steps:

step 1, performing three-stage crushing on volcanic ash rock to obtain volcanic ash rock powder with the average particle size of 3 mm;

step 2, putting the volcanic limestone powder obtained in the step 1 into a ball mill, sequentially adding triethanolamine, ethylene glycol and diethanolamine into the ball mill, and grinding for 20-40 min; then adding water glass and sodium hydroxide into the ball mill, and continuing to grind for 1 h;

step 3, on the basis of the step 2, after the powder is ground for 1 hour, continuously adding higher fatty acid, titanate and organic chromium into the grinding machine and continuously grinding until the specific surface area of the modified volcanic limestone powder is (500-550) m²/kg。

Technical Field

The invention belongs to the field of building materials, and particularly relates to an ultrahigh-performance concrete prepared from modified volcanic ash rock powder.

Background

Ultra-high performance concrete, abbreviated as UHPC, is widely favored by engineering users and concrete material researchers because of its properties such as ultra-high mechanical strength, ultra-high toughness, and excellent durability. At present, research works related to ultra-high performance concrete, such as performance indexes of UHPC, test methods, application technical rules and standards of premix products, are being implemented gradually, and the ultra-high performance concrete is expected to be developed more vigorously.

The raw materials for preparing the ultra-high performance concrete mainly comprise Portland cement with the strength grade of 52.5 and above, silica fume, slag powder, fly ash, quartz sand, steel fiber, an additive and the like. Wherein the silicate cement, the silica fume, the slag powder and the fly ash are used as cementing materials, the material particles can form closest packing under the appropriate proportion, and react with the mixing water to generate hydration products such as C-S-H gel, calcium hydroxide, ettringite and the like, so that the material can be cemented with materials such as quartz sand, steel fiber and the like. However, the cementing material required by the preparation of the ultra-high performance concrete is generally high in quality, so that the preparation cost is greatly increased, and the application range of the ultra-high performance concrete in building engineering is limited.

Volcanic ash rock as a mineral resource is abundant in China and widely distributed. The volcanic limestone crystalline phase structure mainly comprises quartz, potash feldspar, plagioclase and metal minerals. The proportion of the volcanic ash rock active minerals is over 75 percent, wherein the content of aluminum oxide (Al2O) is about 12 percent, and the loss on ignition can be as low as 0.2 percent. The ultra-high performance concrete prepared by using the powder volcanic ash rock powder ground by the volcanic ash rock can directly reduce the consumption of cement, is beneficial to the reasonable allocation of mineral resources in China, reduces carbon emission, can also greatly reduce the preparation cost of the ultra-high performance concrete, and has positive effects on promoting the application of UHPC in building engineering and realizing sustainable development.

Disclosure of Invention

In order to overcome the problems in the prior art, the invention provides the ultrahigh-performance concrete containing the modified volcanic ash rock powder, which has the advantages of good plasticizing effect, good fluidity and low preparation cost.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the ultrahigh-performance concrete prepared from the modified volcanic ash rock powder comprises the following components in parts by weight:

preferably, the surface area of the slag powder is 300-350m²Per kg, water content not more than 1% and loss on ignition not more than 2%.

Preferably, the average particle size of the silica fume is 1-3 μm, and the volume weight is 1650-³(ii) a Wherein the mass of the silica fume with the particle size less than 1 μm in the silica fume is 80 percent of the mass of the silica fume.

Preferably, the metakaolin has an activity index of greater than 110, a loss on ignition of less than 0.7%, and an average particle size of 10 to 20 μm.

Preferably, the quartz sand consists of quartz sand with the average particle size of 20-40 meshes, quartz sand with the average particle size of 40-70 meshes and quartz sand with the average particle size of 70-140 meshes according to the mass ratio of 6:3: 1. Preferably, the concentration of the graphene oxide is 3.0%, and the average particle size of the carboxylic acid modified nano C-S-H is 40-80 nm. When the concentration of the graphene oxide is 3.0%, crack expansion of the ultra-high performance concrete can be effectively inhibited, and the tensile property of the ultra-high performance concrete is improved; when the average particle size of the carboxylic acid modified nano C-S-H is 40-80nm, the activity of the modified volcanic ash powder, the slag powder and the metakaolin can be effectively excited, and the early mechanical strength of the ultrahigh concrete is improved.

Preferably, the modified volcanic ash rock powder is obtained by modifying volcanic ash rock powder with the average grain diameter of 3mm by using a grinding aid, a surfactant and an activity excitant; wherein the specific surface area of the obtained modified volcanic ash rock powder is 500-550m²/kg。

Preferably, the grinding aid consists of triethanolamine, ethylene glycol and diethanolamine, the surface modifier consists of higher fatty acid, titanate and organic chromium, and the active activator consists of sodium hydroxide and water glass; wherein the triethanolamine, the ethylene glycol, the diethanolamine, the higher fatty acid, the titanate, the organic chromium, the sodium hydroxide, the water glass and the volcanic ash rock powder respectively comprise the following components in parts by weight: 0.01-0.04 part, 0.01-0.03 part, 0.01-0.04 part, 0.02-0.05 part, 2-5 parts, 1-3 parts and 100 parts.

Preferably, the modulus of the water glass is 1; the mass concentration of the sodium hydroxide is 40%.

Preferably, the preparation method of the modified volcanic ash rock powder specifically comprises the following steps:

step 1, performing three-stage crushing on volcanic ash rock to obtain volcanic ash rock powder with the average particle size of 3 mm;

step 2, putting the volcanic limestone powder obtained in the step 1 into a ball mill, sequentially adding triethanolamine, ethylene glycol and diethanolamine into the ball mill, and grinding for 20-40 min; then adding water glass and sodium hydroxide into the ball mill, and continuing to grind for 1 h;

step 3, on the basis of the step 2, after the powder is ground for 1 hour, continuously adding higher fatty acid, titanate and organic chromium into the grinding machine and continuously grinding until the specific surface area of the modified volcanic limestone powder is (500-550) m²/kg。

Compared with the prior art, the invention has the following beneficial effects:

(1) the ultrahigh-performance concrete prepared from the modified volcanic ash rock powder has the characteristics of good fluidity, high strength, low preparation cost and the like, so that the popularity and the market competitiveness of the ultrahigh-performance concrete prepared by the invention are improved. Therefore, the ultra-high performance concrete is a concrete with high comprehensive performance.

(2) In the invention, the slag powder, the silica fume, the metakaolin and the quartz sand are limited, so that on one hand, the slag powder, the silica fume and the metakaolin used in the invention have enough activity, and on the other hand, the modified volcanic ash rock powder also has enough activity. On the other hand, the particle sizes of the slag powder, the silica fume, the metakaolin and the quartz sand are limited, so that various powder particles in the ultra-high performance concrete are favorably and closely stacked, and the mechanical strength of the ultra-high performance concrete is provided.

(3) The grinding aid consisting of triethanolamine, diethanolamine and ethylene glycol is added in the preparation process of the modified volcanic ash rock powder, on one hand, the grinding aid can be preferentially adsorbed on the surface of the volcanic ash rock powder to reduce the surface energy, and meanwhile, the grinding aid molecules can also be adsorbed on the inner wall of a crack of a solid material to prevent the crack from closing and promote the crack to expand, thereby playing a role in grinding aid; on the other hand, the method can also promote the ion dissolution of 52.5-grade portland cement particles and accelerate the early hydration of the mineral phase tricalcium silicate of the cement clinker. The activator water glass (sodium silicate modulus 1) and the sodium hydroxide solution not only enable the particles to be fully contacted with the alkali-activated components and to be uniformly dispersed, but also enable the alkali-activator molecules to be gathered at the cracks on the surfaces of the particles, and the reactivity of the volcanic ash rock powder is remarkably improved along with the accumulation of the surface energy of the particles. The high-grade fatty acid, titanate and organic chromium surface modifier can be preferentially adsorbed on the surfaces of porous volcanic ash rock powder particles, so that the adsorption of the polycarboxylic acid water reducer on the modified volcanic ash rock powder is reduced, the plasticizing effect of the polycarboxylic acid water reducer is improved, meanwhile, the hydrophilic groups on the surfaces of the volcanic ash rock powder particles increase the flowability among the particles, and the flowability of the ultrahigh-performance concrete prepared from the modified volcanic ash rock powder is improved.

Detailed Description

1. 52.5-grade portland cement:

the specific surface area of the Portland cement of grade 52.5 in the invention is not less than 450m²Perkg, initial setting time of not less than 45min and initial setting time of not more than 400 min.

2. Polycarboxylic acid modified nano C-S-H:

the polycarboxylic acid modified nanometer C-S-H in the invention refers to nanometer calcium silicate hydrate modified by polycarboxylic acid.

3. Preparing volcanic ash rock powder:

the volcanic ash rock powder with the thickness of 3mm is prepared by three-stage crushing, and specifically comprises the following three-stage crushing:

and step S1, putting the volcanic limestone into a jaw crusher, and crushing the volcanic limestone into volcanic limestone particles with the particle size of less than 300 mm.

And S2, further crushing the volcanic limestone particles obtained in the step S1 by using a cone crusher to obtain small volcanic limestone particles with the average particle size of less than 30 mm.

And S3, crushing the volcanic ash rock granules obtained in the step S2 into volcanic ash rock powder with the particle size of 3mm by using an edit press.

The pozzolana powders in the following examples were all prepared using the above method.

Examples

The technical solution of the present invention will be further clearly and completely described with reference to the following examples, wherein the raw materials used in the examples of the present invention are all commercially available.

Example 1

The ultrahigh-performance concrete prepared from the modified volcanic ash rock powder comprises the following components in parts by weight:

the components are mixed and stirred for 2-3min to obtain the ultra-high performance concrete, and the ultra-high performance concrete obtained in the embodiment is subjected to performance tests of the expansion degree, the retentivity and the compressive strength, and the performance test results are shown in table 1.

Specifically, the surface area of the slag powder is 300-350m²Per kg, water content not more than 1 percent and loss on ignition not more than 2 percent. The average grain diameter of the silica fume is 1-3 mu m, the volume weight is 1650-³(ii) a Wherein the mass of the silica fume with the grain diameter less than 1 μm is 80% of the mass of the silica fume. The metakaolin has an activity index of greater than 110, a loss on ignition of less than 0.7%, and an average particle size of 10- μm. The quartz sand is composed of quartz sand with the average particle size of 20 meshes, quartz sand with the average particle size of 40 meshes and quartz sand with the average particle size of 70 meshes according to the mass ratio of 6:3: 1. The concentration of the graphene oxide is 3.0%, and the average particle size of the carboxylic acid modified nano C-S-H is 40 nm. The modified volcanic ash rock powder is obtained by modifying volcanic ash rock powder with the average grain diameter of 3mm by using a grinding aid, a surfactant and an activity excitant, and the preparation of the modified volcanic ash rock powder specifically comprises the following steps:

step 1, performing three-stage crushing on the volcanic ash rock to obtain volcanic ash rock powder with the average particle size of 3 mm.

Step 2, putting 100 parts by weight of the volcanic limestone powder obtained in the step 1 into a ball mill, sequentially adding 0.01 part by weight of triethanolamine, 0.01 part by weight of ethylene glycol and 0.01 part by weight of diethanolamine into the ball mill, and grinding for 20 min; then adding 1 part of water glass and 2 parts of sodium hydroxide into the ball mill, and continuing to grind for 1 hour; wherein the modulus of the water glass is 1, and the mass concentration of the sodium hydroxide is 40%.

Step 3, on the basis of the step 2, after grinding for 1 hour, continuously adding 0.01 part of higher fatty acid, 0.02 part of titanate and 0.02 part of organic chromium into a grinding machine according to parts by weight, and continuously grinding until the specific surface area of the obtained mixture is 500m²/kg of modified pozzolana powder.

Example 2

The ultrahigh-performance concrete prepared from the modified volcanic ash rock powder comprises the following components in parts by weight:

the components are mixed and stirred for 2-3min to obtain the ultra-high performance concrete, and the ultra-high performance concrete obtained in the embodiment is subjected to performance tests of the expansion degree, the retentivity and the compressive strength, and the performance test results are shown in table 1.

Specifically, the surface area of the slag powder is 300-350m²Per kg, water content not more than 1 percent and loss on ignition not more than 2 percent. The average grain diameter of the silica fume is 1-3 mu m, the volume weight is 1650-³(ii) a Wherein the mass of the silica fume with the grain diameter less than 1 μm is 80% of the mass of the silica fume. The metakaolin has an activity index of greater than 110, a loss on ignition of less than 0.7% and an average particle size of 20 μm. Mean of quartz sandThe quartz sand with the grain diameter of 40 meshes, the quartz sand with the average grain diameter of 70 meshes and the quartz sand with the average grain diameter of 140 meshes are composed according to the mass ratio of 6:3: 1. The concentration of the graphene oxide is 3.0%, and the average particle size of the carboxylic acid modified nano C-S-H is 80 nm. The modified volcanic ash rock powder is obtained by modifying volcanic ash rock powder with the average grain diameter of 3mm by using a grinding aid, a surfactant and an activity excitant, and the preparation of the modified volcanic ash rock powder specifically comprises the following steps:

step 1, performing three-stage crushing on the volcanic ash rock to obtain volcanic ash rock powder with the average particle size of 3 mm.

Step 2, putting 100 parts by weight of the volcanic limestone powder obtained in the step 1 into a ball mill, sequentially adding 0.04 part by weight of triethanolamine, 0.03 part by weight of ethylene glycol and 0.03 part by weight of diethanolamine into the ball mill, and grinding for 40 min; then adding 3 parts of water glass and 5 parts of sodium hydroxide into the ball mill, and continuing to grind for 1 hour; wherein the modulus of the water glass is 1, and the mass concentration of the sodium hydroxide is 40%.

Step 3, on the basis of the step 2, after grinding for 1 hour, continuously adding 0.04 part by weight of higher fatty acid, 0.05 part by weight of titanate and 0.05 part by weight of organic chromium into the grinding machine, and continuously grinding until the specific surface area of the obtained powder is 550m²/kg of modified pozzolana powder.

Example 3

The ultrahigh-performance concrete prepared from the modified volcanic ash rock powder comprises the following components in parts by weight:

the components are mixed and stirred for 2-3min to obtain the ultra-high performance concrete, and the ultra-high performance concrete obtained in the embodiment is subjected to performance tests of the expansion degree, the retentivity and the compressive strength, and the performance test results are shown in table 1.

Specifically, the surface area of the slag powder is 300-350m²Per kg, water content not more than 1 percent and loss on ignition not more than 2 percent. Average particle size of silica fume1-3 μm, a volume weight of 1650-³(ii) a Wherein the mass of the silica fume with the grain diameter less than 1 μm is 80% of the mass of the silica fume. The metakaolin has an activity index of greater than 110, a loss on ignition of less than 0.7% and an average particle size of 15 μm. The quartz sand is composed of quartz sand with an average particle size of 30 meshes, quartz sand with an average particle size of 55 meshes and quartz sand with an average particle size of 105140 meshes according to a mass ratio of 6:3: 1. The concentration of the graphene oxide is 3.0%, and the average particle size of the carboxylic acid modified nano C-S-H is 6080 nm. The modified volcanic ash rock powder is obtained by modifying volcanic ash rock powder with the average grain diameter of 3mm by using a grinding aid, a surfactant and an activity excitant, and the preparation of the modified volcanic ash rock powder specifically comprises the following steps:

step 1, performing three-stage crushing on the volcanic ash rock to obtain volcanic ash rock powder with the average particle size of 3 mm.

Step 2, putting 100 parts by weight of the volcanic limestone powder obtained in the step 1 into a ball mill, sequentially adding 0.03 part by weight of triethanolamine, 0.02 part by weight of ethylene glycol and 0.02 part by weight of diethanolamine into the ball mill, and grinding for 30 min; then adding 2 parts of water glass and 4 parts of sodium hydroxide into the ball mill, and continuing to grind for 1 hour; wherein the modulus of the water glass is 1, and the mass concentration of the sodium hydroxide is 40%.

Step 3, on the basis of the step 2, after grinding for 1 hour, continuously adding 0.02 part of higher fatty acid, 0.04 part of titanate and 0.04 part of organic chromium into the grinding machine according to the parts by weight, and continuously grinding until the specific surface area of the obtained mixture is 520m²/kg of modified pozzolana powder.

Comparative example 1

The concrete comprises the following components in parts by weight:

the components are mixed and stirred for 2-3min to obtain the ultra-high performance concrete, and the ultra-high performance concrete obtained in the embodiment is subjected to performance tests of the expansion degree, the retentivity and the compressive strength, and the performance test results are shown in table 1.

And (3) data analysis:

the high performance concretes obtained in examples 1 to 3 above were subjected to the tests for the properties of extension, retention and compressive strength. The expansion and the retention thereof were measured according to the method specified in GB8076-2008 "concrete Admixture" standard, and the compressive strength was measured according to the method specified in GB/T31387-. The results of the performance test are shown in Table 1.

Table 1 test table for performance of high performance concrete obtained in each example

In summary, the present invention solves the technical deficiencies of the prior art. By adding the modified volcanic ash rock powder, the plasticizing effect and the fluidity of the high-performance concrete are improved, and the preparation cost of the high-performance concrete is reduced, so that the popularity and the market competitiveness of the ultra-high-performance concrete prepared by the invention are improved.

While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.