CN111636700A - Winter V-shaped stiff column concrete heat preservation maintenance construction method - Google Patents
Winter V-shaped stiff column concrete heat preservation maintenance construction method Download PDFInfo
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- CN111636700A CN111636700A CN202010463512.7A CN202010463512A CN111636700A CN 111636700 A CN111636700 A CN 111636700A CN 202010463512 A CN202010463512 A CN 202010463512A CN 111636700 A CN111636700 A CN 111636700A
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G21/00—Preparing, conveying, or working-up building materials or building elements in situ; Other devices or measures for constructional work
- E04G21/24—Safety or protective measures preventing damage to building parts or finishing work during construction
- E04G21/246—Safety or protective measures preventing damage to building parts or finishing work during construction specially adapted for curing concrete in situ, e.g. by covering it with protective sheets
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Abstract
The invention relates to the field of mixtures containing cement materials for curing, solidifying or hardening, in particular to a winter V-shaped stiff column concrete heat-preservation curing construction method. A winter V-shaped stiff column concrete heat preservation maintenance construction method is characterized by comprising the following steps: the method is implemented in sequence according to the following steps: pouring concrete; curing the concrete; and thirdly, temperature measurement and heat preservation. The invention has high engineering quality and shortened construction period.
Description
Technical Field
The invention relates to the field of mixtures containing cement materials for curing, solidifying or hardening, in particular to a winter V-shaped stiff column concrete heat-preservation curing construction method.
Background
The concrete construction is greatly influenced by the environmental temperature, the environmental temperature is low in winter, and the concrete is not generally constructed, so that the construction time is greatly prolonged, and the improvement of the construction efficiency is limited.
Disclosure of Invention
The invention provides a construction method for ensuring engineering quality and shortening construction period in order to overcome the defects of the prior art, and discloses a winter V-shaped stiff column concrete heat preservation maintenance construction method.
The invention achieves the purpose by the following technical scheme:
a winter V-shaped stiff column concrete heat preservation maintenance construction method is characterized by comprising the following steps: the method is implemented in sequence according to the following steps:
pouring concrete: setting the lowest outdoor temperature as T during winter construction, adding antifreezing agent and early strength agent into concrete when T is more than or equal to 0 ℃ and less than 5 ℃,
when T is more than or equal to minus 10 ℃ and less than 0 ℃, adding an antifreezing agent and an early strength agent into the concrete, wrapping two layers of rock wool heat preservation quilt and one layer of color strip cloth on the outer surface of the concrete to implement covering heat preservation,
when the temperature T is more than or equal to minus 15 ℃ and less than minus 10 ℃, the concrete is added with the antifreezing agent and the early strength agent, and the outer surface of the concrete is wrapped with a layer of electric heat tracing, two layers of rock wool heat preservation quilts and a layer of color stripe cloth to implement heat tracing covering heat preservation,
the addition amount of the antifreezing agent and the early strength agent is 3 to 6 percent of the mass of the cement in the concrete,
when T is less than-15 ℃, concrete pouring is suspended, and after the weather is warmed up, concrete pouring is started,
the freezing critical strength of the concrete is not less than 30% of the designed concrete strength grade value, and when T is not less than-15 ℃, the freezing critical strength of the concrete is not less than 4.0 MPa;
the concrete of the V-shaped stiff columns is wrapped with electric tracing heat by an electric heating method, the mold-entering temperature of the concrete is increased during concrete pouring, after pouring, a plastic film is timely attached to the surface of exposed concrete, then rock wool is covered on the surface of the exposed concrete, heat is preserved, and the heat preservation thickness of important parts such as edges and corners is increased to be 2-3 times of that of the important parts.
The concrete slump is controlled to be 160-180 mm, the initial setting time is controlled to be within 4hour, and the slump loss cannot be too large so as to avoid influencing concrete pouring;
concrete curing: wrapping electric tracing by adopting a comprehensive heat storage method or an electric heating method, maintaining without detaching a template, detaching the template after the concrete reaches the designed strength, preventing wind and concrete from being dehydrated during maintenance, slowly cooling the concrete, and stopping heat preservation after the concrete reaches the temperature of freezing critical strength; besides the normal specified number of groups, the concrete test block is additionally provided with a plurality of groups for curing under the same condition as the structure, wherein one group is used for testing the strength of the concrete before being frozen, and the other group is used for testing the strength of the concrete after being cured at the normal temperature for 28 days;
thirdly, temperature measurement and heat preservation: the top, the middle and the bottom of each V-shaped stiff column are respectively provided with a thermometer, the temperature measuring end of each thermometer is embedded in the V-shaped stiff column for 10cm, the thermometers are respectively arranged at a construction site, a concrete tank and a column template, the thermometers are used for measuring the atmospheric temperature, the concrete tank outlet temperature, the concrete mold inlet temperature, the initial temperature after the concrete is molded and the curing temperature, and the thermometers are used for measuring the atmospheric temperature, the concrete tank outlet temperature, the concrete mold inlet temperature and the initial temperature and the curing temperature once every four hours before the concrete reaches the freezing critical strength. The specific work content is as follows:
1. the construction site manager is responsible for various works such as temperature measurement (atmospheric temperature, concrete can discharging temperature and mold entering temperature; initial temperature and curing temperature after concrete enters a mold), heat preservation and the like of the project, and the manager needs to read temperature measurement records every day, take measures and report in time when finding abnormality.
2. Managers need to inquire the conditions and problems of temperature measurement, heat preservation and the like every day, and timely assist field construction managers to solve construction problems.
3. When measuring temperature, the temperature measuring end of the thermometer is sealed by heat insulating material, so that the thermometer is isolated from the outside air, the temperature in the hole is accurately measured, and the record is made.
4. Thermometric records measured every four hours before the freezing threshold intensity is reached are submitted to a data clerk for filing and review.
The winter V-shaped stiff column concrete heat preservation maintenance construction method is characterized by comprising the following steps:
in the first step, the first step is carried out,
P.O42.5R type ordinary portland cement is selected as cement of the concrete, the quality stability and the uniformity are ensured,
the concrete discharging temperature is not lower than 20 ℃, the concrete molding temperature is not lower than 5 ℃,
in order to improve the early strength of concrete and reduce the self-contraction of concrete, a polycarboxylic acid type antifreezing agent is added into the concrete, and specifically, methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, diethylene glycol, ethylene glycol butyl ether, propylene glycol butyl ether, ethylene glycol butyl ether acetate, methylene dichloride, 1-dichloroethane, 1, 2-dichloroethane, dimethyl sulfoxide, formamide, calcium chloride, sodium acetate, magnesium chloride and other substances can be selected,
considering that the strength of the concrete in the winter period is slowly increased, when the temperature is lower than 0 ℃, the early strength agent is added to ensure that the concrete has enough early strength to resist the sudden change of the atmospheric temperature, such as the temperature reduction caused by the attack of cold flow, to ensure that the newly cast concrete is not frozen in the early stage, the early strength agent is selected from chloride, sulfate, nitric acid-nitrite or organic matter, the chloride can be selected from calcium chloride, sodium chloride or aluminum chloride, the sulfate can be selected from sodium sulfate, potassium sulfate or calcium sulfate, the nitric acid-nitrite is selected from calcium nitrite-calcium nitrate, calcium nitrate-urea, calcium nitrite-calcium nitrate-calcium chloride or calcium nitrite-calcium nitrate-calcium chloride-uric acid, the organic matter is selected from triethanolamine, calcium formate, acetic acid, calcium acetate or triisopropanolamine,
when pouring, the water temperature of the added water is 40-60 ℃,
the concrete mixing plant should carry out the model selection test of the additives such as the antifreeze and the early strength admixture in advance, carry out various performance tests on the selected additives according to the standard requirements, simultaneously ensure the technical storage of the antifreeze at the temperature of-20 ℃, carry out the adaptation work of the winter application series mixing proportion according to the selected antifreeze, ensure that the economic, reasonable and technically feasible mixing proportion is provided for the winter production,
the supply of concrete, including mixing and transportation, and pumping, must be insulated, for example, by coating the surface of the tank car with insulation material such as cotton wadding. And (4) compiling a concrete supply plan according to the requirement of the construction progress, and arranging concrete pumps and concrete transport vehicles. In the construction process, communication and scheduling are enhanced to ensure the mold-entering temperature of the concrete, the mold-entering temperature of the concrete is preferably controlled to be about 10 ℃ and the lowest temperature is not lower than 5 ℃,
the invention has the following beneficial effects:
1. the method has the advantages of effectively optimizing the heat preservation and maintenance of the V-shaped stiff column concrete in the winter period, along with reliable technology, economy, reasonability, energy consumption reduction, engineering quality guarantee and construction period shortening, and is a practical construction method.
2. The method solves the problem of difficult control of the construction quality of the concrete in the winter period, has reliable technology, economy and reasonability, reduces energy consumption, ensures the engineering quality, shortens the construction period, is a practical construction method, and has wide application range.
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Detailed Description
The invention is further illustrated by the following specific examples.
Example 1
A winter V-shaped stiff column concrete heat preservation maintenance construction method is implemented according to the following steps in sequence:
pouring concrete: the cement of the concrete is P.O42.5R type ordinary portland cement, the quality stability and the uniformity are ensured, the temperature of the concrete taken out of a tank is not lower than 20 ℃, the temperature of the concrete entering a mold is not lower than 5 ℃,
setting the lowest outdoor temperature as T during winter construction, adding antifreezing agent and early strength agent into concrete when T is more than or equal to 0 ℃ and less than 5 ℃,
when T is more than or equal to minus 10 ℃ and less than 0 ℃, adding an antifreezing agent and an early strength agent into the concrete, wrapping two layers of rock wool heat preservation quilt and one layer of color strip cloth on the outer surface of the concrete to implement covering heat preservation,
when the temperature T is more than or equal to minus 15 ℃ and less than minus 10 ℃, the concrete is added with the antifreezing agent and the early strength agent, and the outer surface of the concrete is wrapped with a layer of electric heat tracing, two layers of rock wool heat preservation quilts and a layer of color stripe cloth to implement heat tracing covering heat preservation,
the addition amount of the antifreezing agent and the early strength agent is 3 to 6 percent of the mass of the cement in the concrete,
when T is less than-15 ℃, concrete pouring is suspended, and after the weather is warmed up, concrete pouring is started,
the freezing critical strength of the concrete is not less than 30% of the designed concrete strength grade value, and when T is not less than-15 ℃, the freezing critical strength of the concrete is not less than 4.0 MPa;
in order to improve the early strength of concrete and reduce the self-contraction of concrete, a polycarboxylic acid type antifreezing agent is added into the concrete, and specifically, methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, diethylene glycol, ethylene glycol butyl ether, propylene glycol butyl ether, ethylene glycol butyl ether acetate, methylene dichloride, 1-dichloroethane, 1, 2-dichloroethane, dimethyl sulfoxide, formamide, calcium chloride, sodium acetate, magnesium chloride and other substances can be selected,
considering that the strength of the concrete in the winter period is slowly increased, when the temperature is lower than 0 ℃, the early strength agent is added to ensure that the concrete has enough early strength to resist the sudden change of the atmospheric temperature, such as the temperature reduction caused by the attack of cold flow, to ensure that the newly cast concrete is not frozen in the early stage, the early strength agent is selected from chloride, sulfate, nitric acid-nitrite or organic matter, the chloride can be selected from calcium chloride, sodium chloride or aluminum chloride, the sulfate can be selected from sodium sulfate, potassium sulfate or calcium sulfate, the nitric acid-nitrite is selected from calcium nitrite-calcium nitrate, calcium nitrate-urea, calcium nitrite-calcium nitrate-calcium chloride or calcium nitrite-calcium nitrate-calcium chloride-uric acid, the organic matter is selected from triethanolamine, calcium formate, acetic acid, calcium acetate or triisopropanolamine,
the concrete of the V-shaped stiff columns is wrapped with electric tracing heat by an electric heating method, the mold-entering temperature of the concrete is increased during concrete pouring, after pouring, a plastic film is timely attached to the surface of exposed concrete, then rock wool is covered on the surface of the exposed concrete, heat is preserved, and the heat preservation thickness of important parts such as edges and corners is increased to be 2-3 times of that of the important parts.
The concrete slump is controlled to be 160-180 mm, the initial setting time is controlled to be within 4hour, and the slump loss cannot be too large so as to avoid influencing concrete pouring;
when pouring, the water temperature of the added water is 40-60 ℃,
the concrete mixing plant should carry out the model selection test of the additives such as the antifreeze and the early strength admixture in advance, carry out various performance tests on the selected additives according to the standard requirements, simultaneously ensure the technical storage of the antifreeze at the temperature of-20 ℃, carry out the adaptation work of the winter application series mixing proportion according to the selected antifreeze, ensure that the economic, reasonable and technically feasible mixing proportion is provided for the winter production,
the supply of concrete, including mixing and transportation, and pumping, must be insulated, for example, by coating the tank car with insulation such as cotton wadding. And (4) compiling a concrete supply plan according to the requirement of the construction progress, and arranging concrete pumps and concrete transport vehicles. In the construction process, communication and scheduling are enhanced to ensure the mold-entering temperature of the concrete, the mold-entering temperature of the concrete is preferably controlled to be about 10 ℃ and the lowest temperature is not lower than 5 ℃,
concrete curing: wrapping electric tracing by adopting a comprehensive heat storage method or an electric heating method, maintaining without detaching a template, detaching the template after the concrete reaches the designed strength, preventing wind and concrete from being dehydrated during maintenance, slowly cooling the concrete, and stopping heat preservation after the concrete reaches the temperature of freezing critical strength; besides the normal specified number of groups, the concrete test block is additionally provided with a plurality of groups for curing under the same condition as the structure, wherein one group is used for testing the strength of the concrete before being frozen, and the other group is used for testing the strength of the concrete after being cured at the normal temperature for 28 days;
thirdly, temperature measurement and heat preservation: the top, the middle and the bottom of each V-shaped stiff column are respectively provided with a thermometer, the temperature measuring end of each thermometer is embedded in the V-shaped stiff column for 10cm, the thermometers are respectively arranged at a construction site, a concrete tank and a column template, the thermometers are used for measuring the atmospheric temperature, the concrete tank outlet temperature, the concrete mold inlet temperature, the initial temperature after the concrete is molded and the curing temperature, and the thermometers are used for measuring the atmospheric temperature, the concrete tank outlet temperature, the concrete mold inlet temperature and the initial temperature and the curing temperature once every four hours before the concrete reaches the freezing critical strength. The specific work content is as follows:
1. the construction site manager is responsible for various works such as temperature measurement (atmospheric temperature, concrete can discharging temperature and mold entering temperature; initial temperature and curing temperature after concrete enters a mold), heat preservation and the like of the project, and the manager needs to read temperature measurement records every day, take measures and report in time when finding abnormality.
2. Managers need to inquire the conditions and problems of temperature measurement, heat preservation and the like every day, and timely assist field construction managers to solve construction problems.
3. When measuring temperature, the temperature measuring end of the thermometer is sealed by heat insulating material, so that the thermometer is isolated from the outside air, the temperature in the hole is accurately measured, and the record is made.
4. Thermometric records measured every four hours before the freezing threshold intensity is reached are submitted to a data clerk for filing and review.
Claims (2)
1. A winter V-shaped stiff column concrete heat preservation maintenance construction method is characterized by comprising the following steps: the method is implemented in sequence according to the following steps:
pouring concrete: setting the lowest outdoor temperature as T during winter construction, adding antifreezing agent and early strength agent into concrete when T is more than or equal to 0 ℃ and less than 5 ℃,
when T is more than or equal to minus 10 ℃ and less than 0 ℃, adding an antifreezing agent and an early strength agent into the concrete, wrapping two layers of rock wool heat preservation quilt and one layer of color strip cloth on the outer surface of the concrete to implement covering heat preservation,
when the temperature T is more than or equal to minus 15 ℃ and less than minus 10 ℃, the concrete is added with the antifreezing agent and the early strength agent, and the outer surface of the concrete is wrapped with a layer of electric heat tracing, two layers of rock wool heat preservation quilts and a layer of color stripe cloth to implement heat tracing covering heat preservation,
the addition amount of the antifreezing agent and the early strength agent is 3 to 6 percent of the mass of the cement in the concrete,
when T is less than-15 ℃, concrete pouring is suspended, and after the weather is warmed up, concrete pouring is started,
the freezing critical strength of the concrete is not less than 30% of the designed concrete strength grade value, and when T is not less than-15 ℃, the freezing critical strength of the concrete is not less than 4.0 MPa;
the concrete of the V-shaped stiff columns is wrapped with electric tracing heat by an electric heating method, the mold-entering temperature of the concrete is increased during concrete pouring, after pouring, a plastic film is timely attached to the surface of exposed concrete, then rock wool is covered on the surface of the exposed concrete, heat is preserved, and the heat preservation thickness of edges and corners is increased to be 2-3 times of that of the surface of the exposed concrete.
Controlling the concrete slump to be 160-180 mm, and controlling the initial setting time to be within 4 hour;
concrete curing: wrapping electric tracing by adopting a comprehensive heat storage method or an electric heating method, maintaining without detaching a template, detaching the template after the concrete reaches the designed strength, preventing wind and concrete from being dehydrated during maintenance, slowly cooling the concrete, and stopping heat preservation after the concrete reaches the temperature of freezing critical strength;
thirdly, temperature measurement and heat preservation: the top, the middle and the bottom of each V-shaped stiff column are respectively provided with a thermometer, the temperature measuring end of each thermometer is embedded in the V-shaped stiff column for 10cm, the thermometers are respectively arranged at a construction site, a concrete tank and a column template, the thermometers are used for measuring the atmospheric temperature, the concrete tank outlet temperature, the concrete mold inlet temperature, the initial temperature after the concrete is molded and the curing temperature, and the thermometers are used for measuring the atmospheric temperature, the concrete tank outlet temperature, the concrete mold inlet temperature and the initial temperature and the curing temperature once every four hours before the concrete reaches the freezing critical strength.
2. The concrete heat-preservation maintenance construction method for the V-shaped stiff columns in the winter period as claimed in claim 1, characterized in that:
firstly, the concrete discharging temperature is not lower than 20 ℃, the concrete molding temperature is not lower than 5 ℃,
the antifreezing agent is polycarboxylic acid type, the early strength agent is chloride, sulfate, nitric acid-nitrite or organic matter,
the water temperature of the added water is 40-60 ℃ during pouring.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0416674A (en) * | 1990-05-09 | 1992-01-21 | Uehara Keishi Kk | Heat insulating sheet for curing concrete and insulating method |
| CN106285006A (en) * | 2016-08-31 | 2017-01-04 | 绍兴职业技术学院 | A kind of cold district concreting in cold-weather method |
| CN106285004A (en) * | 2016-08-08 | 2017-01-04 | 中国建筑第八工程局有限公司 | Aluminum alloy formwork system teletostage comprehensive accumulation of heat construction technology |
| CN108951636A (en) * | 2018-07-13 | 2018-12-07 | 中国电建集团铁路建设有限公司 | A kind of extremely frigid zones subway station concrete construction heat preserving method |
| CN111075196A (en) * | 2019-12-03 | 2020-04-28 | 中交第三航务工程局有限公司 | Concrete pouring process |
-
2020
- 2020-05-27 CN CN202010463512.7A patent/CN111636700A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0416674A (en) * | 1990-05-09 | 1992-01-21 | Uehara Keishi Kk | Heat insulating sheet for curing concrete and insulating method |
| CN106285004A (en) * | 2016-08-08 | 2017-01-04 | 中国建筑第八工程局有限公司 | Aluminum alloy formwork system teletostage comprehensive accumulation of heat construction technology |
| CN106285006A (en) * | 2016-08-31 | 2017-01-04 | 绍兴职业技术学院 | A kind of cold district concreting in cold-weather method |
| CN108951636A (en) * | 2018-07-13 | 2018-12-07 | 中国电建集团铁路建设有限公司 | A kind of extremely frigid zones subway station concrete construction heat preserving method |
| CN111075196A (en) * | 2019-12-03 | 2020-04-28 | 中交第三航务工程局有限公司 | Concrete pouring process |
Non-Patent Citations (2)
| Title |
|---|
| 翟玉峰: "冬期混凝土工程施工方法的研究与应用", 《中国优秀硕士学位论文全文数据库 工程科技II辑》 * |
| 郝臣君: "寒冷地区冬季混凝土施工质量控制研究", 《中国优秀硕士学位论文全文数据库 工程科技II辑》 * |
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Application publication date: 20200908 |