阅读说明：本技术 一种高温环境下用于异型结构的滑模施工控制方法 (Sliding form construction control method for special-shaped structure in high-temperature environment ) 是由 张凤举 张伟 陈杨化 冯子恒 喻宁招 王坤 于 2021-07-29 设计创作，主要内容包括：提供一种高温环境下用于异型结构的滑模施工控制方法,包括：步骤1,配合比设计及设定；步骤2,实施保温措施；步骤3,设置偏移扭转监测平台以及纠偏纠扭平台进行监测和纠正；以及步骤4,实施混凝土质量控制。该方法涉及滑模施工的相关控制要点与细节,可以大大提高滑模施工的质量与效率,扩展了滑模这一高效施工技术的使用环境与领域,从而使得滑模施工质量不再受人力、物料供应、天气、组织管理、设备操作等方面的影响,降低造成大的质量或者安全问题的风险。(The slip form construction control method for the special-shaped structure in the high-temperature environment comprises the following steps: step 1, designing and setting a mixing ratio; step 2, implementing heat preservation measures; step 3, setting an offset torsion monitoring platform and a deviation rectifying and torsion correcting platform for monitoring and correcting; and step 4, implementing concrete quality control. The method relates to relevant control key points and details of slip form construction, can greatly improve the quality and efficiency of slip form construction, and expands the use environment and field of the slip form which is an efficient construction technology, so that the slip form construction quality is not affected by manpower, material supply, weather, organization management, equipment operation and the like, and the risk of causing large quality or safety problems is reduced.)

1. A slip form construction control method for a special-shaped structure in a high-temperature environment is characterized by comprising the following steps:

step 1, designing and setting a mixing ratio;

step 2, implementing heat preservation measures;

step 3, setting an offset torsion monitoring platform and a deviation rectifying and torsion correcting platform for monitoring and correcting; and

and 4, implementing concrete quality control.

2. The slip-form construction control method for the special-shaped structure in the high-temperature environment according to claim 1, characterized in that the step 1 comprises the following steps:

step 11, performing a velocity calculation, comprising: the construction speed of each day, namely the lifting height of the formwork and the height of the slip form formwork are set according to the condition of the man-machine, and the relation between the initial setting time of the concrete and the sliding speed is obtained according to the formula (1):

wherein the content of the first and second substances,

h-template height;

a-the distance from the surface of the poured concrete to the upper opening of the template;

h₀-each concrete casting layer thickness;

T₂-the time required for the concrete strength to reach a predetermined value;

v-the sliding speed of the template;

after the initial setting time is calculated, designing the slip form concrete mixing ratio design;

step 12, designing the slip form concrete mixing ratio: on the premise of ensuring the strength, the initial setting time is changed by adjusting the mixing amount of external additives such as a water reducing agent, a retarder, an early strength agent and the like, various combinations are set, and the initial setting time at different temperatures is obtained.

3. The slip-form construction control method for the special-shaped structure in the high-temperature environment according to claim 2, characterized in that the step 12 comprises: adopting a slip form to construct concrete with certain slump.

4. The slip-form construction control method for the special-shaped structure in the high-temperature environment according to claim 2, characterized in that the step 12 further comprises: the admixture dosage is finely adjusted in the conventional slip form construction so as to deal with various construction conditions.

5. The slip-form construction control method for the special-shaped structure in the high-temperature environment according to claim 1, wherein the step 2 comprises the following steps: the large platform of the sliding mode is arranged to provide a shielding effect, and the side face of the large platform adopts a double-layer dense mesh net as a containment to provide cooling and heat preservation measures for the large platform and the template.

6. The slip-form construction control method for the special-shaped structure in the high-temperature environment according to claim 5, characterized in that the cooling and heat-preserving measure is a combination method, and the combination method comprises the following steps:

step 21, strictly controlling the mold-entering temperature, and controlling the mixing ratio, the raw materials and the processing process, adding ice and other measures to be not higher than 30 ℃;

step 22, adding heat insulation measures to the steel die, and fixing heat insulation cotton on the back of the template by using a binding tape to play a good role in heat insulation;

step 23, the outer side of the slip form platform is shaded by adopting a fireproof blanket, so that direct sunlight is avoided, and rapid water loss caused by high-temperature insolation is reduced;

24, arranging a plurality of cold water fans in the platform, and installing an air conditioner in a closed area on the construction platform to avoid the influence of high temperature of desert on slip form construction;

and 25, adding spraying measures, arranging spraying pipes on each operating platform along the wall, and cooling the steel mould by insulating cotton with cold water.

7. The slip-form construction control method for the special-shaped structure in the high-temperature environment according to claim 1, characterized in that the step 3 comprises the following steps:

step 31, arranging five laser plummets on the ground, arranging laser targets on the sliding mode platform, and analyzing the deviation condition of each point to monitor the deviation and torsion condition of the platform;

step 32, the deviation-rectifying and torsion-rectifying platform structure connects the ends of the portal frames with each other through a steel strand chain block to actively control the inclination or torsion direction of the portal frames so as to achieve the purpose of deviation-rectifying and torsion-rectifying; when the platform is twisted clockwise, the chain block is tightened to enable all the door frames to have the tendency of falling anticlockwise, and the platform gradually returns to the original position along with the lifting of the sliding mode; when the platform deviates, the gantry along the deviation direction is adjusted towards the opposite direction, and the platform can reset along with lifting.

8. The slip-form construction control method for the special-shaped structure in the high-temperature environment according to claim 1, characterized in that the step 4 comprises the following steps:

step 41, strictly controlling the concrete to pour in layers, and carrying out reciprocating ring pouring to achieve the balance of concrete distribution;

step 42, before each pouring, cleaning mortar on the surface of the template by using a dust shovel and coating a release agent on the vacant position of the template to prevent concrete from accumulating and blocking in the template;

and 43, correspondingly processing the condition of the demoulded concrete.

9. The slip-form construction control method for the special-shaped structure in the high-temperature environment according to claim 8, wherein the step 43 comprises:

if the demolding concrete has no defects or only micro cracks, finishing and plastering immediately, and then brushing the surface with a curing liquid;

in the process of sliding form contraction and division deformation, if the formwork adjusts the cast-out concrete to generate a scaly surface, large-area contraction and plastering work is carried out;

if the honeycomb pitted surface is generated on the part of the demoulded concrete and the surface cannot be repaired after the initial setting time, firstly, a steel wire brush is used for removing floating slurry and a curing agent on the surface to ensure that the surface is clean, dry, compact, free of dust and high in quality, and a first repairing material is used for repairing the surface;

and if the hole collapse and rib exposure or other large-area quality defects occur in the demoulded concrete, immediately stopping sliding, cleaning residues on the surface or the reinforcing steel bar by using a steel wire brush, smearing and filling by using a second repairing material, and finishing polishing the surface by using a third repairing material after four to five hours.

Technical Field

The invention relates to the technical field of building construction key process control, in particular to a sliding mode construction control method for a special-shaped structure in a high-temperature environment.

Background

The slip form construction is a continuous forming efficient construction method which can be used for structures such as silos, independent columns/piers and the like of non-combined frames, and has the advantages of high automation degree, large space, fast construction and the like. However, the construction quality of the slip form is affected by various aspects such as manpower, material supply, weather, organization management, equipment operation and the like, and a problem in any link may cause a large quality or safety problem. Therefore, the slip form fault tolerance rate is low, especially under the severe high-temperature conditions in the middle east.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a slip form construction control method for a special-shaped structure in a high-temperature environment.

The invention aims to provide a slip form construction control method for a special-shaped structure in a high-temperature environment, which comprises the following steps:

step 1, designing and setting a mixing ratio;

step 2, implementing heat preservation measures;

step 3, setting an offset torsion monitoring platform and a deviation rectifying and torsion correcting platform for monitoring and correcting;

and 4, implementing concrete quality control.

Preferably, the step 1 comprises:

step 11, performing a velocity calculation, comprising: the construction speed of each day, namely the lifting height of the formwork and the height of the slip form formwork are set according to the condition of the man-machine, and the relation between the initial setting time of the concrete and the sliding speed is obtained according to the formula (1):

wherein the content of the first and second substances,

h-template height;

a-the distance from the surface of the poured concrete to the upper opening of the template;

h₀-each concrete casting layer thickness;

T₂-the time required for the concrete strength to reach a predetermined value;

v-the sliding speed of the template;

after the initial setting time is calculated, designing the slip form concrete mixing ratio design;

step 12, designing the slip form concrete mixing ratio: on the premise of ensuring the strength, the initial setting time is changed by adjusting the mixing amount of external additives such as a water reducing agent, a retarder, an early strength agent and the like, various combinations are set, and the initial setting time at different temperatures is obtained.

Preferably, the step 12 includes: concrete is adopted, and the slump is designed to meet the requirement of adapting to slip form construction.

Preferably, the step 12 further comprises: the admixture dosage is finely adjusted in the conventional slip form construction so as to deal with various construction conditions.

Preferably, the step 2 comprises: strictly controlling the mold-entering temperature, and controlling the mixing ratio, the raw materials, the processing process, the ice adding and other measures to be not higher than 30 ℃;

preferably, the step 2 further comprises: the steel die is added with a heat insulation measure, and the heat insulation cotton on the back of the template is fixed by a binding belt, so that a good heat insulation effect is achieved; the outer side of the slip form platform is shaded by adopting a fireproof blanket, so that direct sunlight is avoided, and rapid water loss caused by high-temperature insolation is reduced; a plurality of cold water fans are arranged in the platform, and an air conditioner is installed in a closed area on the construction platform, so that the influence of high temperature of desert on slip form construction is avoided; and spraying measures are added, spraying pipes are arranged on each operating platform along the wall, and the temperature of the heat-insulating cotton outside the steel die is reduced by cold water.

Preferably, the step 3 comprises:

step 31, arranging five laser plummets on the ground, arranging laser targets on the sliding mode platform, and analyzing the deviation condition of each point to monitor the deviation and torsion condition of the platform;

step 32, the deviation-rectifying and torsion-rectifying platform structure connects the ends of the portal frames with each other through a steel strand chain block to actively control the inclination or torsion direction of the portal frames so as to achieve the purpose of deviation-rectifying and torsion-rectifying; when the platform is twisted clockwise, the chain block is tightened to enable all the door frames to have the tendency of falling anticlockwise, and the platform gradually returns to the original position along with the lifting of the sliding mode; when the platform deviates, the gantry along the deviation direction is adjusted towards the opposite direction, and the platform can reset along with lifting.

Preferably, the step 4 comprises:

step 41, strictly controlling the concrete to pour in layers, and carrying out reciprocating ring pouring to achieve the balance of concrete distribution;

step 42, before each pouring, cleaning mortar on the surface of the template by using a dust shovel and coating a release agent on the vacant position of the template to prevent concrete from accumulating and blocking in the template;

and 43, correspondingly processing the condition of the demoulded concrete.

Preferably, the step 43 includes:

if the demolding concrete has no defects or only micro cracks, finishing and plastering immediately, and then brushing the surface with a curing liquid;

in the process of sliding form contraction and division deformation, if the formwork adjusts the cast-out concrete to generate a scaly surface, large-area contraction and plastering work is carried out;

if the honeycomb pitted surface is generated on the part of the demoulded concrete and the surface cannot be repaired after the initial setting time, firstly, a steel wire brush is used for removing floating slurry and a curing agent on the surface to ensure that the surface is clean, dry, compact, free of dust and high in quality, and a first repairing material is used for repairing the surface;

and if the hole collapse and rib exposure or other large-area quality defects occur in the demoulded concrete, immediately stopping sliding, cleaning residues on the surface or the reinforcing steel bars by using a steel wire brush, smearing and filling by using a second repairing material, and finishing polishing by using the surface of a third repairing material after four to five hours.

The invention has the beneficial effects that:

the method relates to relevant control key points and details of slip form construction, can greatly improve the quality and efficiency of slip form construction, and expands the use environment and field of the slip form which is an efficient construction technology. The method has reference significance for future slip form construction under similar projects and similar conditions.

Drawings

FIG. 1 is a schematic flow chart of a slip-form construction control method for a special-shaped structure in a high-temperature environment according to the invention;

FIG. 2 is a graph showing the relationship between the amount of water-reducing agent incorporated and the initial setting time according to a preferred embodiment of the present invention;

FIG. 3 is a graph showing the relationship between the amount of retarder incorporated and the initial setting time according to a preferred embodiment of the present invention.

Fig. 4 is a graph showing the relationship between the initial setting time and the ambient temperature according to a preferred embodiment of the present invention.

Detailed Description

The invention is further illustrated with reference to fig. 1 and the specific embodiment.

In the embodiment, slip-form construction operation of the slip-form tower barrel of the heat absorption tower barrel of a certain photo-thermal and photovoltaic hybrid power generation project in the desert area is taken as an example, and the main control point of slip-form construction of the special-shaped structure in the complex environment of the desert area is explained. Has certain applicability and superiority in construction aiming at similar projects.

The slip form is equipment for forming a concrete structure by continuously and slowly moving a template, and the template can realize a special structural form through deformation, diameter change, torsion and other actions. The effect of the forming depends on the state of the concrete in the formwork and the timing of the sliding of the formwork. Under the severe environment of desert areas, the construction control of the slip form is more complicated due to the influences of sunlight, high temperature, day and night temperature difference and the like, and a set of reliable instant deviation-rectifying and torsion-rectifying scheme is needed to ensure the construction precision. By taking a certain photo-thermal and photovoltaic hybrid power generation project in a desert area as an example, aiming at an ultrahigh cylinder structure, the characteristics of construction period, platform measures, safety, economy and the like are comprehensively considered, slip form construction is the optimal choice, and meanwhile, a series of difficulties of structural abnormity and the desert area must be overcome to ensure the quality.

According to the item, the sliding mode system adopts a portal sliding mode system with a large platform, and the position and the angle of the template can be accurately positioned through screw rod adjustment. The desert area is high in temperature and humidity and long in summer, projects are deep in desert abdominal land, and day and night temperature difference is large. The best lifting time of the slip form is that when the demoulded concrete reaches the initial setting state and the system is lifted, the demoulded concrete is ensured to reach the same initial setting state. Slip form construction suffers from the following problems: 1) the initial setting speed of the concrete is very high at high temperature in the middle east throughout the year, so that the time for improving the initial setting speed must be accurately calculated and controlled; 2) the initial setting time of the concrete is changed along with the great day and night temperature difference; 3) the over-high temperature of the template can cause the concrete to stick to the template, the deformation operation difficulty of the template is large, the molding quality is poor, and the like; 4) the direct irradiation of sunlight can lead the solidification state of the cast concrete to be different, and the phenomena of wall surface cracking, collapse and the like can occur in serious cases. 5) When the platform is lifted, the uneven stress of the platform can be deviated due to different friction forces. 6) If quality problems occur, efficient repair measures are also necessary. The control of the links is the key of slip form construction in the hot areas of middle east China.

The invention aims to provide a slip form construction control method for a special-shaped structure in a high-temperature environment, which comprises the following steps of:

step 1, designing and setting the mix proportion, comprising the following steps:

(1) velocity calculation

The construction speed of each day, namely the lifting height of the formwork and the height of the slip form formwork are set according to the condition of the man-machine, and the relation between the initial setting time of the concrete and the sliding speed can be obtained as shown in the formula (1):

wherein the content of the first and second substances,

h-template height;

a-the distance from the surface of the poured concrete to the upper opening of the template;

h₀-each concrete casting layer thickness;

T₂-the time required for the concrete strength to reach a predetermined value;

v-the sliding speed of the template;

after calculating the initial setting time, the concrete mix proportion design is carried out

(2) Designing a slip form mixing ratio:

the concrete in the initial setting state has low strength, completely loses fluidity and gradually loses plasticity, and the appearance is that the concrete is slightly fingerprinted and does not stick to hands when being pressed by fingers, and the sliding process has 'sand and sand' sound. At this time, the mold stripping effect is best, and the repair and the light collection can be realized.

Optionally, in the technical solution of this embodiment, the predetermined value is 0.7mpa to 1.0 mpa.

This project adopts the concrete that adapts to the slipform construction and have certain slump, considers the retardation time of controlling the concrete according to temperature and slip speed, under the prerequisite of guaranteeing intensity, changes the initial set time through adjusting additive dosage such as water-reducing agent, retarder, early strength agent, has set up multiple combination to obtain the initial set time under the different temperatures. During conventional slip form construction, the mixing amount of each additive can be finely adjusted so as to meet various construction conditions. The mineral powder concrete is commonly used in desert areas, the viscosity of the concrete can be increased after the fly ash is added, the mold sticking condition is more serious under the condition that an early strength agent is added or the temperature of a template is too high, and the mold sticking part can continuously block along with the sliding and the quality is seriously influenced. Therefore, concrete with low content of coal ash and other mineral powder is used as much as possible, the occurrence of die sticking probability is reduced, and the problem of die sticking is basically solved. The initial setting time for each mix ratio is shown in FIG. 4.

As an optional implementation manner, in the technical solution of this embodiment, the concrete may be C50 concrete, and the slump of the C50 concrete may be designed to be 250 ± 20 mm. Considering that the retarding time of the concrete is controlled according to the temperature and the sliding speed, on the premise of ensuring the strength, the initial setting time is changed by adjusting the doping amount of additives such as a water reducing agent, a retarder, an early strength agent and the like, various combinations are set, and the initial setting time at different temperatures is obtained. During conventional slip form construction, the mixing amount of each additive can be finely adjusted so as to meet various construction conditions. In other alternative embodiments, concrete adapted to other conditions may be used.

As shown in FIG. 2, the relationship between the water reducing agent addition amount and the initial setting time is shown in FIG. 3, the relationship between the retarder addition amount and the initial setting time is shown, and through the relationship line, technicians can better master the initial setting condition of concrete so as to carry out corresponding operation. FIG. 4 shows the relationship between the initial setting time and the ambient temperature, so that the technician can better grasp the initial setting conditions of different admixtures after use according to the ambient temperature. Step 2, implementing a high-temperature sliding mode control combination measure, comprising the following steps of:

step 21, strictly controlling the mold-entering temperature, and controlling the mixing ratio, the raw materials and the processing process, adding ice and other measures to be not higher than 30 ℃;

step 22, adding heat insulation measures to the steel die, and fixing heat insulation cotton on the back of the template by using a binding tape to play a good role in heat insulation;

step 23, the outer side of the slip form platform is shaded by adopting a fireproof blanket, so that direct sunlight is avoided, and rapid water loss caused by high-temperature insolation is reduced;

24, arranging a plurality of cold water fans in the platform, and installing an air conditioner in a closed area on the construction platform to avoid the influence of high temperature of desert on slip form construction;

and 25, adding spraying measures, arranging spraying pipes on each operating platform along the wall, and cooling the steel mould by insulating cotton with cold water.

The above-mentioned combination method can greatly reduce the temperature of operation space and template.

In order to cope with hot climate in middle east, the operation surface on the platform is protected from direct sunlight, the large platform of the slip form provides a shielding effect, and the side surface of the platform is surrounded by a double-layer dense mesh net to reduce the direct sunlight. Meanwhile, cooling and heat preservation measures are provided for the platform and the template. The heat insulation cotton on the back of the template is fixed by a binding belt, and the heat insulation cotton is kept wet by ice water in the construction process. Meanwhile, spray pipes are arranged on each operating platform along the wall, so that the effects of dust fall and reduction of the temperature of the construction environment can be achieved. A plurality of cold water fans are arranged in the platform, and an air conditioner is installed in a closed area in the tower. The above-mentioned combination method can greatly reduce the temperature of operation space and template.

Step 3, set up the skew and twist reverse the monitoring platform and rectify and twist reverse the platform and monitor and correct, include:

through five laser plummet that set up on ground and the laser target of location on the slipform platform, the skew condition of each point is analyzed in order to monitor the platform skew and twist reverse the condition.

The platform deviation rectifying and torsion correcting method conventionally adopts a platform inclination method, the method has high operation difficulty and poor correcting effect, and particularly, a heavy sliding mode platform is difficult to recover once deviation occurs. This embodiment has designed neotype scheme of rectifying a deviation and rectifying a torsion, as shown in fig. 2 for rectifying a deviation and rectifying a torsion platform structure sketch map, through steel strand wires chain fall with interconnect between the portal, come the slope of active control portal or twist reverse the direction and reach the purpose of rectifying a deviation and rectifying a torsion. When the platform is twisted clockwise, the chain block is tightened to enable all the door frames to have the tendency of falling anticlockwise, and the platform gradually restores to the original position along with lifting of the sliding mode. When the platform deviates, the gantry along the deviation direction is adjusted towards the opposite direction, and the platform can reset along with lifting.

And 4, implementing concrete quality control, comprising the following steps:

the concrete is strictly controlled to be poured in layers, and the reciprocating pouring ring is carried out so as to achieve the balance of concrete distribution. Considering that the temperature of the formwork is always higher than the temperature of the formwork entering, before each pouring, a dust shovel is used for cleaning mortar on the surface of the formwork and brushing a release agent on the vacant position of the formwork, so that the concrete is prevented from accumulating and blocking on the formwork. And (4) finishing and plastering the cast concrete immediately if the cast concrete has no defects or only tiny cracks, and then coating the surface with the curing liquid. In the process of sliding form contraction and division deformation, a scaly surface is generated due to template adjustment, and large-area contraction and finishing work must be carried out by increasing personnel. If the honeycomb pitted surface is locally generated and the surface cannot be repaired after the initial setting time, firstly, a steel wire brush is used for removing floating slurry and a curing agent on the surface, the surface is ensured to be clean, dry, compact, free of dust and high in quality, and the first repairing material is used for repairing the surface. If the hole collapse and rib exposure or other large-area quality defects occur, the sliding is stopped immediately. And similarly, cleaning residues on the surface or the reinforcing steel bar by using a steel wire brush, smearing and filling by using a second repairing material, and finishing the surface by using a third repairing material after four to five hours. The first repair material, the second repair material, and the third repair material may be the same repair material or different repair materials.

In the embodiment, the photo-thermal photovoltaic power generation project heat collection tower slip-form construction in the desert area is taken as an example, and the relevant control key points and details of slip-form construction in the special environment of the desert area are explained, so that the quality and efficiency of slip-form construction can be greatly improved, and the use environment and the field of slip-form, which is an efficient construction technology, are expanded. The method has reference significance for future slip form construction under similar projects and similar conditions.

Although particular embodiments of the invention have been described and illustrated in detail, it should be understood that various equivalent changes and modifications could be made to the above embodiments in accordance with the spirit of the invention, and the resulting functional effects would still fall within the scope of the invention.