A rapid construction method for mass temperature control of water conservancy projects

Abstract

The invention discloses a rapid construction method for large-volume temperature control of a water conservancy project, which specifically comprises the following steps: step one: concrete preparation, using pebbles and crushed stones as coarse aggregates of concrete, which are the main materials constituting concrete, and gravel as fine aggregate of concrete, and adding cement and reinforcing agent for stirring; step two: constructing a steel cage on the pouring base surface, which is the main component for improving the strength of concrete; step three: supporting a formwork outside the steel cage, and dividing it into a primary pouring area and a secondary pouring area, using a split pouring method, and setting partition components in the two pouring areas; on the premise of ensuring the strength of the concrete itself, combining the split-cast concrete into a solid whole to avoid the generation of cracks, and at the same time adding a retarder to prolong the hydration and hardening time of the cement, so that the freshly mixed concrete can maintain plasticity for a long time, thereby adjusting the setting time of the freshly mixed concrete, shortening the overall construction period, and achieving the purpose of rapid construction.

Description

Technical Field

[0001] The invention belongs to the technical field of water conservancy projects, and in particular relates to a rapid construction method for large-volume temperature control of water conservancy projects. Background Art

[0002] In existing large-scale concrete construction, formwork is used to provide support for concrete. The formwork needs to be removed during the initial pouring, and the surface needs to be roughened after removal. After the concrete pouring is completed, the joint formwork can only be removed after the first phase of concrete reaches a certain strength. It usually takes 5-7 days of solidification before the formwork can be removed. Cracks will also appear between each pour of concrete, affecting the quality and life of the project.

[0003] Publication No. CN104032741B discloses a rapid construction method for large-volume temperature control in water conservancy projects. By using a quick-closing net to separate expansion joints, the roughening process can be avoided to achieve rapid construction of volume temperature control, solving the problem of limited working space and combining the first and second sequence concrete into a solid whole. At the same time, it also avoids damage to the structure caused by the vibration of chiseling and roughening. However, the overall operation of this process is cumbersome.

[0004] Publication No. CN112211197A discloses a rapid construction method for large-volume temperature control in water conservancy projects. The method avoids cracks by adding PVC pipes in the concrete, but this arrangement affects the strength of the concrete itself. Summary of the Invention

[0005] The purpose of the present invention is to provide a rapid construction method for large-volume temperature control of water conservancy projects, so as to solve the problems of the existing patents proposed in the above background technology in the rapid construction of large-volume temperature control, such as cumbersome operation and affecting the strength of the concrete itself, and there is still room for improvement in the overall construction efficiency.

[0006] To achieve the above object, the present invention provides the following technical solution: a rapid construction method for large-volume temperature control of a water conservancy project, specifically comprising the following steps:

[0007] Step 1: Concrete preparation, using pebbles and crushed stones as coarse aggregates, which are the main materials of concrete, and gravel as fine aggregates, and adding cement and reinforcing agents for mixing;

[0008] Step 2: Construct a steel cage on the pouring base surface, which is the main component to improve the strength of concrete;

[0009] Step 3: Support the formwork outside the steel cage and divide it into the primary pouring area and the secondary pouring area. Use a split pouring method and set up partition components in the two pouring areas.

[0010] Step 4: Pour concrete in the primary pouring area. After pouring, add retarder to the concrete in the primary pouring area at regular intervals to reduce the drying speed of the moisture in the concrete, and let it stand.

[0011] Step 5: When preparing for the secondary pouring area to pour concrete, add geotextiles adjacent to the first-fixed concrete and add retarder to increase the drying time and reduce the occurrence of cracks. Then, pour the second concrete and remove all supports after the pouring is completed.

[0012] Step 6: Maintain the poured concrete and spray liquid at the connection between the primary pouring area and the secondary pouring area.

[0013] As a preferred technical solution of the present invention, the gravel particle size in step 1 is 0.5cm to 1.0cm, the cement is any one of silicate cement, slag silicate cement, pozzolanic silicate cement and fly ash silicate cement, the reinforcing agent is TS-ZQ, and the coarse aggregate particle size is 1 to 2cm.

[0014] As a preferred technical solution in the present invention, the steel cage in step 2 is composed of multiple stirrups and multiple main steel bars. The multiple stirrups are arranged in an "S" shape on the multiple main steel bars, which can attach more concrete and improve the strength. The stirrups are first-class steel with a diameter of 8MM. The spacing between the reinforced areas is 100MM and they are three-legged stirrups, and the spacing between the non-reinforced areas is 200MM.

[0015] As a preferred technical solution of the present invention, the types of retarders in step 4 include hydroxycarboxylates, Na3PO4, and Na2B4O7.

[0016] As a preferred technical solution of the present invention, in step 4, the time for adding the retarder each time is 20 to 26 hours to avoid adding too much retarder at one time.

[0017] As a preferred technical solution of the present invention, the amount of retarder added each time is 0.05-0.1% of the mass of the concrete, and a normal amount is added and the concrete is left to stand for 2-3 days.

[0018] As a preferred technical solution of the present invention, in step five, during the secondary concrete pouring, a retarder is added in an amount of 0.1 to 0.15% by mass of the concrete.

[0019] As a preferred technical solution of the present invention, the enhancer in step 1 is 8% to 15% of diethylene glycol, 15% to 20% of molasses, 3% to 5% of glycerol, 2% to 4% of triethanolamine, and 2% to 4% of anhydrous sodium sulfite.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] Through the design of the present invention, while ensuring the strength of the concrete itself, the concrete poured in separate parts is combined into a solid whole, thus avoiding the generation of cracks. At the same time, a retarder is added to prolong the hydration and hardening time of the cement, so that the fresh concrete can maintain its plasticity for a longer period of time, thereby adjusting the setting time of the fresh concrete. The overall construction period is shortened, and the purpose of rapid construction is achieved. DETAILED DESCRIPTION

[0022] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0023] Example 1

[0024] The present invention provides a technical solution: a rapid construction method for large-volume temperature control of a water conservancy project, which specifically includes the following steps:

[0025] Step 1: Concrete preparation, using pebbles and crushed stones as coarse aggregates and gravel as fine aggregates, and adding cement and reinforcing agents for mixing;

[0026] Step 2: Construct the steel cage on the casting base surface;

[0027] Step 3: Support the formwork outside the steel cage and divide it into the primary pouring area and the secondary pouring area, and set up partition components in the two pouring areas;

[0028] Step 4: Pour concrete in the primary pouring area. After pouring, add retarder to the concrete in the primary pouring area at regular intervals. Under the premise of ensuring the strength of the concrete itself, the concrete poured in separate parts is combined into a solid whole to avoid the generation of cracks. At the same time, the retarder is added to prolong the hydration and hardening time of the cement, so that the fresh concrete can maintain plasticity for a longer period of time, thereby adjusting the setting time of the fresh concrete, and then let it stand;

[0029] Step 5: When preparing for the secondary pouring area to pour concrete, add geotextiles adjacent to the first fixed concrete and add retarder to pour the second concrete. After the pouring is completed, remove all supports.

[0030] Step 6: Maintain and cure the poured concrete, and spray liquid at the connection between the primary pouring area and the secondary pouring area. The overall construction period is short, achieving the goal of rapid construction.

[0031] In this embodiment, the gravel particle size in step 1 is 0.5 cm, the cement is any one of silicate cement, slag silicate cement, pozzolanic silicate cement and fly ash silicate cement, and the reinforcing agent is TS-ZQ to improve the strength of the concrete, and the coarse aggregate particle size is 1 cm.

[0032] In this embodiment, the steel cage in step 2 is composed of multiple stirrups and multiple main steel bars. The multiple stirrups are arranged in an "S" shape on the multiple main steel bars. The stirrups are first-class steel with a diameter of 8MM. The spacing between the reinforced areas is 100MM and they are three-legged stirrups. The spacing between the non-reinforced areas is 200MM.

[0033] In this embodiment, the types of retarder in step 4 include hydroxycarboxylate, Na3PO4, and Na2B4O7.

[0034] In this embodiment, in step 4, the time for adding the retarder each time is 20 hours.

[0035] In this embodiment, the amount of retarder added each time is 0.05% of the mass of the concrete, and the concrete is left to stand for 2 days.

[0036] In this embodiment, in step five, during the secondary concrete pouring, a retarder is added at a concentration of 0.1% by mass of the concrete.

[0037] In this embodiment, the enhancer in step 1 is 8% diethylene glycol, 15% taffy, 3% glycerol, 2% triethanolamine, and 2% anhydrous sodium sulfite.

[0038] Example 2

[0039] The difference from Example 1 is that in this embodiment, the gravel particle size in step 1 is 0.7 cm, the cement is any one of silicate cement, slag silicate cement, pozzolanic silicate cement and fly ash silicate cement, and the reinforcing agent is TS-ZQ to improve the strength of the concrete, and the coarse aggregate particle size is 1 cm.

[0040] In this embodiment, the steel cage in step 2 is composed of multiple stirrups and multiple main steel bars. The multiple stirrups are arranged in an "S" shape on the multiple main steel bars. The stirrups are first-class steel with a diameter of 8MM. The spacing between the reinforced areas is 100MM and they are three-legged stirrups. The spacing between the non-reinforced areas is 200MM.

[0041] In this embodiment, the types of retarder in step 4 include hydroxycarboxylate, Na3PO4, and Na2B4O7.

[0042] In this embodiment, in step 4, the time for adding the retarder each time is 24 hours.

[0043] In this embodiment, the amount of retarder added each time is 0.07% of the mass of the concrete, and the concrete is left to stand for 2.5 days.

[0044] In this embodiment, in step five, during the secondary concrete pouring, a retarder is added at a concentration of 0.07% by mass of the concrete.

[0045] In this embodiment, the enhancer in step 1 is 12% diethylene glycol, 18% taffy, 4% glycerol, 3% triethanolamine, and 3% anhydrous sodium sulfite.

[0046] Example 3

[0047] The difference from the above embodiment is that in this embodiment, the gravel particle size in step 1 is 1.0 cm, the cement is any one of silicate cement, slag silicate cement, pozzolanic silicate cement and fly ash silicate cement, and the reinforcing agent is TS-ZQ to improve the strength of concrete, and the coarse aggregate particle size is 2 cm.

[0048] In this embodiment, the steel cage in step 2 is composed of multiple stirrups and multiple main steel bars. The multiple stirrups are arranged in an "S" shape on the multiple main steel bars. The stirrups are first-class steel with a diameter of 8MM. The spacing between the reinforced areas is 100MM and they are three-legged stirrups. The spacing between the non-reinforced areas is 200MM.

[0049] In this embodiment, the types of retarder in step 4 include hydroxycarboxylate, Na3PO4, and Na2B4O7.

[0050] In this embodiment, in step 4, the time for adding the retarder each time is 26 hours.

[0051] In this embodiment, the amount of retarder added each time is 0.1% of the mass of the concrete, and the concrete is left to stand for 3 days.

[0052] In this embodiment, in step five, during the secondary concrete pouring, a retarder is added at a concentration of 0.1% by mass of the concrete.

[0053] In this embodiment, the enhancer in step 1 is 15% diethylene glycol, 20% taffy, 5% glycerol, 4% triethanolamine, and 4% anhydrous sodium sulfite.

[0054] Although embodiments of the present invention have been shown and described (see the detailed description above for details), it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, and the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A rapid construction method for large-volume temperature control of water conservancy projects, characterized by: The specific steps include: Step 1: Concrete preparation, using pebbles and crushed stones as coarse aggregates and gravel as fine aggregates, and adding cement and reinforcing agents for mixing; Step 2: Construct a steel cage on the casting base surface; Step 3: Support the formwork outside the steel cage and divide it into the primary pouring area and the secondary pouring area, and set up partition components in the two pouring areas; Step 4: Pour concrete in the primary pouring area. After pouring is completed, add retarder to the concrete in the primary pouring area at regular intervals and let it stand; Step 5: When preparing for the secondary pouring area to pour concrete, add geotextiles adjacent to the first fixed concrete and add retarder to pour the second concrete. After the pouring is completed, remove all supports. Step 6: Maintain the poured concrete and spray liquid at the connection between the primary pouring area and the secondary pouring area; The gravel particle size in step 1 is 0.5 cm to 1.0 cm, the cement is any one of Portland cement, slag Portland cement, pozzolanic Portland cement and fly ash Portland cement, the reinforcing agent is TS-ZQ, and the coarse aggregate particle size is 1 to 2 cm; The steel cage in step 2 is composed of a plurality of stirrups and a plurality of main steel bars. The plurality of stirrups are arranged in an "S" shape on the plurality of main steel bars. The stirrups are first-class steel with a diameter of 8 mm. The spacing between the reinforced areas is 100 mm and is a three-legged stirrup. The spacing between the non-reinforced areas is 200 mm. The types of retarder in step 4 include hydroxycarboxylates, Na3PO4, and Na2B4O7; In the step 4, the time interval for adding the retarder each time is 20 to 26 hours; In step 4, the amount of retarder added each time is 0.05% to 0.1% of the concrete mass, and the standing time is 2 to 3 days; In step five, during the secondary concrete pouring, a retarder is added at a rate of 0.1% to 0.15% of the mass of the concrete.