CN110818351A - Plastic concrete for runner cushion layer and preparation method thereof - Google Patents
Plastic concrete for runner cushion layer and preparation method thereof Download PDFInfo
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- CN110818351A CN110818351A CN201911131198.6A CN201911131198A CN110818351A CN 110818351 A CN110818351 A CN 110818351A CN 201911131198 A CN201911131198 A CN 201911131198A CN 110818351 A CN110818351 A CN 110818351A
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
- C04B28/02—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing hydraulic cements other than calcium sulfates
- C04B28/04—Portland cements
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
- C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/50—Mortars, concrete or artificial stone characterised by specific physical values for the mechanical strength
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Ceramic Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Structural Engineering (AREA)
- Organic Chemistry (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
A plastic concrete for a runner cushion layer and a preparation method thereof relate to the field of preparation of hydraulic engineering structural concrete, and the plastic concrete comprises the following raw materials in parts by weight: 286 parts of a cementing material; aggregate 1695 parts; 0.419 part of water reducing agent; 254 parts of water; the aggregate sand rate is 45%, and the cementing material comprises the following raw materials: 86-114 parts of cement; 72-100 parts of fly ash; 86-114 parts of bentonite. The plastic concrete has proper strength, elastic modulus and impermeability, and has excellent adaptability to the construction environment of the runner cushion layer.
Description
Technical Field
The invention relates to the field of preparation of concrete of hydraulic engineering structures, in particular to plastic concrete for a runner cushion layer and a preparation method thereof.
Background
In the hydraulic engineering of China, low-strength rigid concrete is generally used as a cushion foundation, but the rigid concrete has high strength, large elastic modulus and low plasticity, and is easy to crack locally, so that the seepage-proofing performance of the concrete is reduced. The water conservancy project structural cushion layer not only needs to ensure that the upper part or the lateral part has certain bearing capacity when the water is full, but also needs to have elastic recovery capacity capable of bearing frequent load and pressure application, and has certain anti-permeability performance. Therefore, in the actual construction process, more plastic concrete is adopted, compared with rigid concrete, the plastic concrete can meet the requirements of strength, deformation and impermeability, and the economical efficiency of the plastic concrete is better. The plastic concrete is applied to a plurality of large and medium hydropower stations, such as a small wave bottom main dam, a secondary upper cofferdam of a water gap hydropower station, a secondary dam of a reservoir at the Danjiang river mouth, a cofferdam of a rock-separated power plant and the like.
However, in the prior art, the plastic concrete has a contradiction relation in the research of several technical indexes of strength, elastic modulus and impermeability, and the use proportion of each raw material is lack of systematic research. Particularly, when the plastic concrete is applied to the flow channel environment, the existing plastic concrete is subjected to various stress environments (water is introduced, water is not introduced, the amount of water is large, the amount of water is small, and the like), so that the strength, the elastic modulus and the impermeability of the existing plastic concrete cannot meet the use requirements or only meet the requirements in the early stage.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide the plastic concrete for the runner cushion layer and the preparation method thereof, wherein the plastic concrete has proper strength, elastic modulus and impermeability and has excellent adaptability to the construction environment of the runner cushion layer.
In order to achieve the above purposes, the technical scheme is as follows:
the plastic concrete for the runner cushion layer comprises the following raw materials in parts by weight: 286 parts of a cementing material; aggregate 1695 parts; 0.419 part of water reducing agent; 254 parts of water; the aggregate sand rate is 45%, and the cementing material comprises the following raw materials: 86-114 parts of cement; 72-100 parts of fly ash; 86-114 parts of bentonite.
On the basis of the technical scheme, the ratio of the cement, the fly ash and the bentonite in parts by weight is 7: 5: 8.
on the basis of the technical scheme, the ratio of the cement, the fly ash and the bentonite in parts by weight is 7: 6: 7.
on the basis of the technical scheme, the ratio of the cement, the fly ash and the bentonite in parts by weight is 7: 7: 6.
on the basis of the technical scheme, 42.5-grade portland cement is adopted as the cement, II-grade fly ash is adopted as the fly ash, and secondary sodium bentonite is adopted as the bentonite.
On the basis of the technical scheme, the water reducing agent is a polycarboxylic acid high-performance water reducing agent with the water reducing rate of more than or equal to 25%.
On the basis of the technical scheme, the aggregate comprises coarse aggregate and fine aggregate, the coarse aggregate adopts continuous graded broken stones with the particle size of 5-20 mm, and the fine aggregate adopts natural river sand with the fineness modulus of 2.3-3.0 mm.
On the basis of the technical scheme, tap water is adopted as the water.
The invention also discloses a preparation method of the plastic concrete, which comprises the following steps:
s1: adding the weighed aggregate, cement, fly ash and bentonite into a stirrer, and uniformly stirring;
s2: and (4) mixing the water reducing agent with water, adding the mixture into the stirrer, and stirring uniformly again.
On the basis of the technical scheme, 42.5-grade portland cement is adopted as the cement, II-grade fly ash is adopted as the fly ash, and secondary sodium bentonite is adopted as the bentonite; the water reducing agent is a polycarboxylic acid high-performance water reducing agent with the water reducing rate of more than or equal to 25 percent; the aggregate comprises coarse aggregate and fine aggregate, the coarse aggregate is continuous graded broken stone with the particle size of 5-20 mm, and the fine aggregate is natural river sand with the fineness modulus of 2.3-3.0 mm.
The invention has the following beneficial effects:
the plastic concrete is between rigid concrete and bentonite, and has certain strength and certain plastic property; the cementing material of the plastic concrete comprises cement, fly ash and bentonite, wherein the cement provides early strength and meets the design requirement and the standard-standard early strength requirement; the fly ash provides later strength and impermeability of concrete, and reduces the cement consumption; bentonite can replace part of cement in concrete, and provides low strength and low elastic modulus of plastic concrete.
According to the physical and chemical properties of each cementing material, the mixing proportion of cement, fly ash and bentonite in the cementing material is researched, and the performance index required by design is achieved through a proper proportion, so that the plastic concrete has proper strength and elastic modulus and good anti-permeability performance; the plastic concrete provided by the invention not only meets the construction requirements in strength, but also has the elastic recovery capability of bearing frequent load and pressure, and has excellent adaptability to the construction environment of a runner cushion layer.
Meanwhile, the plastic concrete disclosed by the invention is low in material cost and low in cost, and is convenient to popularize.
Detailed Description
The present invention will be described in further detail with reference to examples.
The plastic concrete for the runner cushion comprises the following raw materials in parts by weight:
286 parts of a cementing material; aggregate 1695 parts; 0.419 part of water reducing agent; 254 portions of water. Wherein, the aggregate sand rate is 45%; the cementing material comprises the following raw materials: 86-114 parts of cement; 72-100 parts of fly ash; 86-114 parts of bentonite.
The invention researches the mixing proportion of cement, fly ash and bentonite in the cementing material, and develops a proper proportion, so that the plastic concrete has excellent adaptability to the construction environment of the runner cushion and has good comprehensive performance.
Preferably, the ratio of the cement, the fly ash and the bentonite in parts by weight is 7: 5: 8.
preferably, the ratio of the cement, the fly ash and the bentonite in parts by weight is 7: 6: 7.
preferably, the ratio of the cement, the fly ash and the bentonite in parts by weight is 7: 7: 6.
specifically, 42.5-grade portland cement is adopted as cement, II-grade fly ash is adopted as fly ash, and secondary sodium bentonite is adopted as bentonite.
Further, the water reducing agent is a polycarboxylic acid high-performance water reducing agent with the water reducing rate of more than or equal to 25 percent.
Preferably, the aggregate comprises coarse aggregate and fine aggregate, the coarse aggregate adopts continuous graded broken stones with the particle size of 5-20 mm, and the fine aggregate adopts natural river sand with the fineness modulus of 2.3-3.0 mm.
In this example, the aggregate sand rate was 45%, that is, 5.5 parts of coarse aggregate and 4.5 parts of fine aggregate were included per 10 parts of aggregate by mass.
In this example, tap water was used as the water for the plastic concrete.
Example one
The plastic concrete for the runner cushion comprises the following raw materials in parts by weight as shown in Table 1 (example No. 1).
Example two
The difference from the first example is that the raw material components are shown in table 1 (example No. 2) in parts by weight.
EXAMPLE III
The difference from the first example is that the raw material components are shown in table 1 (example No. 3) in parts by weight.
Example four
The difference from the first example is that the raw material components are shown in table 1 (example No. 4) in parts by weight.
EXAMPLE five
The difference from the first example is that the raw material components are shown in table 1 (example No. 5) in parts by weight.
EXAMPLE six
The difference from the first example is that the raw material components are shown in table 1 (example No. 6) in parts by weight.
EXAMPLE seven
The difference from the first example is that the raw material components are shown in table 1 (example No. 7) in parts by weight.
TABLE 1
In the above 7 examples, the water-cement ratio (ratio of water to cement in parts by weight) of the wet concrete was 0.89.
The above 7 examples were tested for various performance indexes including 7d compressive strength, 28d compressive strength, 60d compressive strength, 28d elastic modulus, permeation resistance coefficient and slump, and the test results are shown in table 2.
TABLE 2
Wherein, the 7d compressive strength, the 28d compressive strength and the 60d compressive strength respectively represent the early, middle (namely the conventional concrete compressive strength) and later compressive strengths of the plastic concrete; the plastic concrete of the invention requires 28d compressive strength to meet the requirements of more than or equal to 3.0MPa and less than or equal to 6.0 MPa; and the 7d compressive strength and the 28d compressive strength are taken as reference and are as close to 3.0MPa as possible.
The plastic concrete of the invention requires that the 28d elastic modulus meets the requirements of more than or equal to 900MPa and less than or equal to 1200 MPa.
The plastic concrete of the invention requires that the impermeability coefficient is more than or equal to 1.10-7And is less than or equal to 9.10- 7The range of cm/s is required.
The slump of the plastic concrete is related to the water-cement ratio of the plastic concrete, represents the integral working performance of the plastic concrete, and the slump of the plastic concrete for the runner cushion layer is 180mm, so that the design requirement is met.
The plastic concrete satisfying the above parameters (which are obtained from construction experience) can best adapt to the runner environment in terms of compressive strength, plastic properties (corresponding to elasticity) and anti-permeability properties, and is applied to the runner cushion.
By comparing the parameters, it can be seen that the permeation resistance coefficient and the slump of the performance indexes of the embodiments 1-2 meet the requirements, but the 28d compressive strength and the 28d elastic modulus do not meet the requirements.
In examples 3 to 7, the indexes of 28d compressive strength, 28d elastic modulus, permeation resistance coefficient and slump property all meet the requirements.
However, in the actual construction process, the 60d compressive strength and the 28d elastic modulus of the embodiment 6 or 7 tend to be required upper limits, and from the economical point of view, the performance indexes of the examples 3 to 5 are better than those of the examples 6 to 7.
The cementing material comprises cement, fly ash and bentonite, wherein the cement provides early strength and meets the design requirement and the early strength requirement of the standard specification; the fly ash provides later strength and impermeability of concrete, and reduces the cement consumption; bentonite can replace part of cement in concrete, and provides low strength and low elastic modulus of plastic concrete. According to the invention, the mixing proportion of cement, fly ash and bentonite in the cementing material is researched according to the physical and chemical properties of the cementing material, and the plastic concrete can better adapt to the flow channel environment and has good comprehensive performance through proper proportion. Compared with the existing plastic concrete, the plastic concrete has certain strength and can meet the construction requirements; the composite material has the advantages of proper elastic modulus, good plasticity, good adaptability to the runner environment, adaptability to the variable stress environment of the runner, good anti-permeability and excellent adaptability to the construction environment of the runner cushion layer.
The invention also discloses a preparation method of the plastic concrete for the runner cushion layer, which comprises the following steps:
s1: adding the weighed aggregate, cement, fly ash and bentonite into a stirrer, and uniformly stirring;
s2: and (4) mixing the water reducing agent with water, adding the mixture into the stirrer, and stirring uniformly again.
Furthermore, 42.5-grade portland cement is adopted as cement, II-grade fly ash is adopted as fly ash, and secondary sodium bentonite is adopted as bentonite; the water reducing agent is a polycarboxylic acid high-performance water reducing agent with the water reducing rate of more than or equal to 25 percent; the aggregate comprises coarse aggregate and fine aggregate, the coarse aggregate is continuous graded broken stone with the grain diameter of 5-20 mm, and the fine aggregate is natural river sand with the fineness modulus of 2.3-3.0 mm.
The present invention is not limited to the above-described embodiments, and it will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the principle of the present invention, and such modifications and improvements are also considered to be within the scope of the present invention. Those not described in detail in this specification are within the skill of the art.
Claims (10)
1. The plastic concrete for the runner cushion layer is characterized by comprising the following raw materials in parts by weight:
286 parts of a cementing material;
aggregate 1695 parts;
0.419 part of water reducing agent;
254 parts of water;
the aggregate sand rate is 45%, and the cementing material comprises the following raw materials:
86-114 parts of cement;
72-100 parts of fly ash;
86-114 parts of bentonite.
2. The plastic concrete according to claim 1, wherein: the ratio of the cement to the fly ash to the bentonite in parts by weight is 7: 5: 8.
3. the plastic concrete according to claim 1, wherein: the ratio of the cement to the fly ash to the bentonite in parts by weight is 7: 6: 7.
4. the plastic concrete according to claim 1, wherein: the ratio of the cement to the fly ash to the bentonite in parts by weight is 7: 7: 6.
5. the plastic concrete according to claim 1, wherein: the cement is 42.5-grade portland cement, the fly ash is II-grade fly ash, and the bentonite is secondary sodium bentonite.
6. The plastic concrete according to claim 1, wherein: the water reducing agent is a polycarboxylic acid high-performance water reducing agent with the water reducing rate of more than or equal to 25 percent.
7. The plastic concrete according to claim 1, wherein: the aggregate comprises coarse aggregate and fine aggregate, the coarse aggregate is continuous graded broken stone with the particle size of 5-20 mm, and the fine aggregate is natural river sand with the fineness modulus of 2.3-3.0 mm.
8. The plastic concrete according to claim 1, wherein: the water is tap water.
9. A method of producing a wet concrete for a runner mat as claimed in any one of claims 1 to 8, comprising the steps of:
s1: adding the weighed aggregate, cement, fly ash and bentonite into a stirrer, and uniformly stirring;
s2: and (4) mixing the water reducing agent with water, adding the mixture into the stirrer, and stirring uniformly again.
10. The method of claim 9, wherein: the cement is 42.5-grade portland cement, the fly ash is II-grade fly ash, and the bentonite is secondary sodium bentonite; the water reducing agent is a polycarboxylic acid high-performance water reducing agent with the water reducing rate of more than or equal to 25 percent; the aggregate comprises coarse aggregate and fine aggregate, the coarse aggregate is continuous graded broken stone with the particle size of 5-20 mm, and the fine aggregate is natural river sand with the fineness modulus of 2.3-3.0 mm.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201911131198.6A CN110818351A (en) | 2019-11-19 | 2019-11-19 | Plastic concrete for runner cushion layer and preparation method thereof |
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| CN201911131198.6A CN110818351A (en) | 2019-11-19 | 2019-11-19 | Plastic concrete for runner cushion layer and preparation method thereof |
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111807792A (en) * | 2020-07-29 | 2020-10-23 | 广东省水利水电科学研究院 | Quartz glass powder plastic concrete and preparation method thereof |
| CN111875316A (en) * | 2020-07-29 | 2020-11-03 | 广东省水利水电科学研究院 | Water-absorbent resin plastic concrete and preparation method thereof |
| CN111943544A (en) * | 2020-07-29 | 2020-11-17 | 广东省水利水电科学研究院 | Plastic concrete and preparation method thereof |
| CN115583812A (en) * | 2022-10-08 | 2023-01-10 | 江西申洪新型材料有限公司 | Composite modified bentonite and application thereof in concrete preparation |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1834054A (en) * | 2005-12-15 | 2006-09-20 | 中国长江三峡工程开发总公司 | High strength, low elasticity and anti-creepage, creeping proof wall material |
| US8636941B1 (en) * | 2012-09-25 | 2014-01-28 | Romeo Ilarian Ciuperca | Methods of making concrete runways, roads, highways and slabs on grade |
| US20150069647A1 (en) * | 2013-09-09 | 2015-03-12 | Romeo Ilarian Ciuperca | Insulated concrete slip form and method of accelerating concrete curing using same |
| CN108706921A (en) * | 2018-06-05 | 2018-10-26 | 中铁十四局集团大盾构工程有限公司 | A kind of plastic concrete and preparation method thereof reinforced for shield end |
-
2019
- 2019-11-19 CN CN201911131198.6A patent/CN110818351A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1834054A (en) * | 2005-12-15 | 2006-09-20 | 中国长江三峡工程开发总公司 | High strength, low elasticity and anti-creepage, creeping proof wall material |
| US8636941B1 (en) * | 2012-09-25 | 2014-01-28 | Romeo Ilarian Ciuperca | Methods of making concrete runways, roads, highways and slabs on grade |
| US20150069647A1 (en) * | 2013-09-09 | 2015-03-12 | Romeo Ilarian Ciuperca | Insulated concrete slip form and method of accelerating concrete curing using same |
| CN108706921A (en) * | 2018-06-05 | 2018-10-26 | 中铁十四局集团大盾构工程有限公司 | A kind of plastic concrete and preparation method thereof reinforced for shield end |
Non-Patent Citations (4)
| Title |
|---|
| 中国电力企业联合会标准化部: "《通用技术标准》", 30 September 1995, 水利电力出版社 * |
| 石中林等: "《建筑材料检测（上）》", 28 February 2013, 华中科技大学出版社 * |
| 胡瑜明等: ""塑性混凝土技术性能的优化研究"", 《国外建材科技》 * |
| 高钟璞等: "《大坝基础防渗墙》", 29 February 2000, 中国电力出版社 * |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111807792A (en) * | 2020-07-29 | 2020-10-23 | 广东省水利水电科学研究院 | Quartz glass powder plastic concrete and preparation method thereof |
| CN111875316A (en) * | 2020-07-29 | 2020-11-03 | 广东省水利水电科学研究院 | Water-absorbent resin plastic concrete and preparation method thereof |
| CN111943544A (en) * | 2020-07-29 | 2020-11-17 | 广东省水利水电科学研究院 | Plastic concrete and preparation method thereof |
| CN115583812A (en) * | 2022-10-08 | 2023-01-10 | 江西申洪新型材料有限公司 | Composite modified bentonite and application thereof in concrete preparation |
| CN115583812B (en) * | 2022-10-08 | 2024-01-23 | 江西申洪新型材料有限公司 | Composite modified bentonite and application thereof in preparing concrete |
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Application publication date: 20200221 |