阅读说明：本技术 一种高强混凝土及其制备方法 (High-strength concrete and preparation method thereof ) 是由 徐磊 屠春军 王裴华 周萍 陈逯浩 魏金 龙荣国 于 2019-10-18 设计创作，主要内容包括：本发明涉及一种高强混凝土及其制备方法,一种高强混凝土包括：水泥、掺合料、细骨料、粗骨料、水和外加剂,所述水泥、掺合料、细骨料、粗骨料、水和外加剂的质量比为(300～500)∶(100～200)∶(600～800)∶(900～1000)∶(100～250)∶(1～10)。高强混凝土的制备方法包括：按照上述原料配比准备材料；向搅拌机投入水泥、掺合料、细骨料搅拌,加入外加剂和水搅拌,再加入粗骨料搅拌；控制混凝土搅拌出机的坍落度和扩展度。本发明所提供的高强混凝土,主要采用细骨料和粗骨料作为原料,其他材料作为辅料,具有力学满足要求,工作性能好,并且在高海拔地区,细骨料和粗骨料易得,因此本发明所提供的高强混凝土适用于高海拔地域超高层泵送的要求。(The invention relates to a high-strength concrete and a preparation method thereof, wherein the high-strength concrete comprises the following components: the cement-based composite material comprises cement, an admixture, fine aggregate, coarse aggregate, water and an additive, wherein the mass ratio of the cement to the admixture to the fine aggregate to the coarse aggregate to the water to the additive is (300-500) to (100-200) to (600-800) to (900-1000) to (100-250) to (1-10). The preparation method of the high-strength concrete comprises the following steps: preparing materials according to the raw material proportion; adding cement, admixture and fine aggregate into a stirrer, stirring, adding additive and water, stirring, adding coarse aggregate and stirring; controlling the slump and the expansion degree of the concrete mixer. The high-strength concrete provided by the invention mainly adopts fine aggregate and coarse aggregate as raw materials, other materials as auxiliary materials, and has the advantages of meeting the mechanical requirements, good working performance and easy obtaining of the fine aggregate and the coarse aggregate in a high-altitude area, so that the high-strength concrete provided by the invention is suitable for the requirement of pumping a super-high layer in the high-altitude area.)

1. A high strength concrete, comprising: the cement-based composite material comprises cement, an admixture, fine aggregate, coarse aggregate, water and an additive, wherein the mass ratio of the cement to the admixture to the fine aggregate to the coarse aggregate to the water to the additive is (300-500) to (100-200) to (600-800) to (900-1000) to (100-250) to (1-10).

2. The high-strength concrete according to claim 1, wherein the mass ratio of the cement to the admixture to the fine aggregate to the coarse aggregate to the water to the admixture is 405: 135: 731: 931 to (180-186) to 8.6.

3. The high-strength concrete according to claim 1, wherein the admixture is a water reducing agent.

4. The high strength concrete of claim 3, wherein the admixture is a PCA800 water reducer.

5. The high strength concrete according to claim 1, wherein the admixture is fly ash.

6. The high-strength concrete according to claim 5, wherein the admixture is class II fly ash or/and class I fly ash.

7. The high-strength concrete as claimed in claim 6, wherein the fine aggregate comprises mountain sand and washing sand, and the mass ratio of the mountain sand to the washing sand is (100-200): (500-600).

8. The high-strength concrete according to claim 7, wherein the mass ratio of the sand stone to the washing sand is 183: 548.

9. The high-strength concrete according to claim 1, wherein the coarse aggregate is 5-20 mm stone.

10. A method of producing a high strength concrete according to any one of claims 1 to 9, comprising:

preparing materials according to the mass ratio of cement, admixture, fine aggregate, coarse aggregate, water and additive of (300-500) to (100-200) to (600-800) to (900-1000) to (100-250) to (1-10);

firstly, adding cement, admixture and fine aggregate into a stirrer, stirring, then adding the admixture and water, stirring, and finally adding coarse aggregate and stirring;

after the stirring is finished, the slump of the concrete mixer is 250 +/-20 mm, and the expansibility is 650 +/-50 mm.

Technical Field

The invention relates to the technical field of building materials, in particular to high-strength concrete and a preparation method thereof.

Background

In high-altitude areas, raw materials for concrete preparation mainly comprise sand and stones, and the mud content of the sand and stones is high; the mineral powder and the fly ash have few acquisition channels and single variety; the humidity is small, the temperature difference is large, the altitude is high, the moisture is easy to dissipate, and the working performance of the concrete is greatly influenced.

Therefore for prior art, under the prerequisite of guaranteeing concrete mechanical properties, this application needs the proportion of adjustment grit, makes the grit become main raw and other ingredient's proportion.

Disclosure of Invention

In order to solve the problems, the invention provides high-strength concrete and a preparation method thereof by adopting the following technical scheme.

In a first aspect, there is provided a high strength concrete comprising: the cement-based composite material comprises cement, an admixture, fine aggregate, coarse aggregate, water and an additive, wherein the mass ratio of the cement to the admixture to the fine aggregate to the coarse aggregate to the water to the additive is (300-500) to (100-200) to (600-800) to (900-1000) to (100-250) to (1-10).

Optionally, the mass ratio of the cement, the admixture, the fine aggregate, the coarse aggregate, the water and the admixture is 405: 135: 731: 931: 180-186: 8.6.

Optionally, in the high-strength concrete, the admixture is a water reducing agent.

Optionally, in the high-strength concrete, the admixture is a PCA800 water reducer.

Optionally, in the high-strength concrete, the admixture is fly ash.

Optionally, in the high-strength concrete, the admixture is class ii fly ash or/and class i fly ash.

Optionally, in the high-strength concrete, the fine aggregate includes mountain sand and washed sand, and the mass ratio of the mountain sand to the washed sand is (100-200): (500-600).

Optionally, in the high-strength concrete, the mass ratio of the sand stone to the washed sand is 183: 548.

Optionally, in the high-strength concrete, the coarse aggregate is 5-20 mm stone.

In a second aspect, a preparation method of the high-strength concrete is provided, and includes:

preparing materials according to the mass ratio of cement, admixture, fine aggregate, coarse aggregate, water and additive of (300-500) to (100-200) to (600-800) to (900-1000) to (100-250) to (1-10);

firstly, adding cement, admixture and fine aggregate into a stirrer, stirring, then adding the admixture and water, stirring, and finally adding coarse aggregate and stirring;

after the stirring is finished, the slump of the concrete mixer is 250 +/-20 mm, and the expansibility is 650 +/-50 mm.

The high-performance concrete pouring method comprises the following steps:

before pouring concrete, a pouring scheme is designed in advance according to engineering characteristics, construction environmental conditions and construction conditions, wherein the pouring scheme comprises a pouring starting point, a pouring progress direction and a pouring thickness;

checking the position, the number and the fastening degree of the cushion blocks of the steel bar protective layer, and performing repeatability check;

if the reinforcing steel bar protective layer meets the construction requirements, before concrete enters a mold, the slump and expansion working performance of the concrete should be measured;

if the slump and the expansion of the concrete meet the construction conditions, pouring is started;

and (3) pouring concrete in a layered continuous pushing mode.

The high-performance concrete vibrating method comprises the following steps:

the concrete is vibrated by adopting an inserted high-frequency vibrating rod, an attached flat vibrator and surface flat vibrator vibrating equipment;

the concrete is vibrated according to a preset process route and a preset mode, and the poured concrete is uniformly and compactly vibrated in time in the concrete pouring process;

in the concrete vibrating process, the stability of the formwork support and the sealing condition of the joint are detected in a reinforcing mode, and slurry leakage is prevented;

and (3) finishing concrete pouring, carefully compacting and leveling the surface of the concrete, and strictly forbidding watering.

The invention has the beneficial effects that:

the high-strength concrete provided by the invention mainly adopts fine aggregate and coarse aggregate as raw materials, other materials as auxiliary materials, and has the advantages of meeting the mechanical requirements, good working performance and easy obtaining of the fine aggregate and the coarse aggregate in a high-altitude area, so that the high-strength concrete provided by the invention is suitable for the requirement of pumping a super-high layer in the high-altitude area.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a flow chart of a method of preparing the high strength concrete of the present invention;

FIG. 2 is a flow chart of the high performance concrete casting method of the present invention;

FIG. 3 is a flow chart of the high performance concrete vibrating method of the present invention.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic views illustrating only the basic structure of the present invention in a schematic manner, and thus show only the constitution related to the present invention.

In high-altitude areas, raw materials for concrete preparation mainly comprise sand and stones, and the mud content of the sand and stones is high; the mineral powder and the fly ash have few acquisition channels and single variety; the humidity is small, the temperature difference is large, the altitude is high, the moisture is easy to dissipate, and the working performance of the concrete is greatly influenced. Based on the special environment of the high-altitude area, the invention provides high-strength concrete, which comprises the following components in percentage by weight: the cement-based composite material comprises cement, an admixture, fine aggregate, coarse aggregate, water and an additive, wherein the mass ratio of the cement to the admixture to the fine aggregate to the coarse aggregate to the water to the additive is (300-500) to (100-200) to (600-800) to (900-1000) to (100-250) to (1-10). The high-strength concrete provided by the invention mainly adopts fine aggregate and coarse aggregate as raw materials, other materials as auxiliary materials, and has the advantages of meeting the mechanical requirements, good working performance and easy obtaining of the fine aggregate and the coarse aggregate in a high-altitude area, so that the high-strength concrete provided by the invention is suitable for the requirement of pumping a super-high layer in the high-altitude area.

Further, the invention provides a preferable scheme, and the high-strength concrete prepared by adopting the following mixture ratio is more economical under the condition of meeting the mechanical use requirement of the high-altitude environment, and specifically comprises the following steps: the mass ratio of the cement to the admixture to the fine aggregate to the coarse aggregate to the water to the admixture is 405: 135: 731: 931 to (180-186) to 8.6.

Furthermore, the invention can improve the workability of cement, reduce the unit water consumption, improve the fluidity of concrete mixture, reduce the unit cement consumption and save cement in order to have the dispersion effect on cement particles. The water reducing agent is adopted as the additive, so that the water consumption in the high-altitude environment is reduced, and the water is saved.

Further, the admixture of the application is a PCA800 water reducing agent. The PCA800 water reducing agent has the functions of greatly reducing water, automatically leveling, high slump retaining, high reinforcement, high durability and the like. The PCA800 water reducing agent has strong adaptability to cement, low mixing amount and convenient use, is particularly suitable for high flow state, high slump loss resistance, high strength and ultrahigh strength concrete engineering, and meets the use requirements of high altitude environment.

The admixture of this application adopts fly ash often, because fly ash can improve concrete mixture's mobility, cohesiveness and water retentivity, makes concrete mixture easily pump sending, casting shaping to reducible slump's loss over time. The fly ash can reduce the cement consumption, and the hydration heat release of the fly ash is little, so that the hydration heat release is reduced, the temperature rise of the concrete during construction is reduced, the temperature crack can be obviously reduced, and the fly ash concrete is particularly favorable for large-volume concrete engineering. Meanwhile, because the specific surface area of the fly ash is large and the adsorption capacity is strong, the fly ash particles can absorb alkali in cement and react with the alkali to consume the alkali.

The admixture of the application can adopt class II fly ash or/and class I fly ash. However, because the I-grade fly ash is very little in the special environment of the high-altitude area, the application usually adopts the II-grade fly ash, and the II-grade fly ash according to the proportion meets the use requirement of the concrete in the high-altitude environment, so that the concrete is more economic and practical.

The fine aggregate comprises mountain sand and washed sand, and the mass ratio of the mountain sand to the washed sand is (100-200): (500-600). The washed sand is the casting raw sand obtained by washing and grading natural silica sand, has low mud content, belongs to medium sand, and has hard texture and clear color; the mountain sand has a good cement adhesion effect due to rough surface, but the mountain sand has complex components, most of the mountain sand contains soil and other organic impurities, and if the soil content is too high, the gray scale of the cement is reduced, and the mountain sand is not firm; therefore, under the condition of comprehensively considering the requirements of the compactness and the mud content of the concrete, the mountain sand and the washed sand adopt the proportion, so that the mixed particle composition continuously belongs to sand in the area II, the impurity content is low, the mud content is low, the fluidity of the concrete can be effectively improved, and the pumping performance of the concrete is ensured.

The application provides an optimal proportion, and the following proportion makes the concrete have better compactness and mud content, specifically as follows: the mass ratio of the sand to the washed sand is 183: 548.

The coarse aggregate is 5-20 mm stone. The mud content is lower than 1%, and 5-20 mm stones reduce the discreteness of the concrete, enhance the workability and enhance the cohesive force, and meet the use requirements of high-altitude concrete.

As shown in fig. 1, a method for preparing the high-strength concrete includes:

s01, preparing materials according to the mass ratio of cement, admixture, fine aggregate, coarse aggregate, water and admixture of (300-500): (100-200): (600-800): (900-1000): (100-250): (1-10);

s02, firstly, adding cement, an admixture and fine aggregate into the stirrer, stirring, then adding the admixture and water, stirring, and finally adding coarse aggregate and stirring;

and S03, after the stirring is finished, the slump of the concrete mixer is 250 +/-20 mm, and the expansibility is 650 +/-50 mm.

As shown in fig. 2, the high performance concrete casting method includes:

s11, before pouring concrete, designing a pouring scheme in advance according to engineering characteristics, construction environmental conditions and construction conditions, wherein the pouring scheme comprises a pouring starting point, a pouring progress direction and a pouring thickness;

s12, checking the position, the number and the fastening degree of the steel bar protective layer cushion block, and performing repeatability check;

s13, if the reinforcing steel bar protective layer meets the construction requirements, before the concrete enters the mould, the slump and the expansion working performance of the concrete should be measured;

s14, if the slump and the expansion of the concrete meet the construction conditions, pouring is started;

and S15, pouring concrete in a layered continuous moving mode.

As shown in fig. 3, the high performance concrete vibrating method includes:

s21, vibrating the concrete by using an insertion high-frequency vibrating bar, an attachment flat vibrator and a surface flat vibrator;

s22, vibrating the concrete according to a preset process route and a preset mode, and uniformly vibrating and compacting the poured concrete in time in the concrete pouring process;

s23, in the concrete vibrating process, the stability of the template support and the joint sealing condition are checked in a reinforcing mode, and slurry leakage is prevented;

and S24, finishing concrete pouring, carefully compacting and leveling the concrete surface, and strictly forbidding water spraying.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.