Transformer substation column integrated fire-resistant non-dismantling formwork and construction method thereof

Abstract

The invention discloses a transformer substation column integrated fireproof non-dismantling formwork and a construction method thereof, and belongs to the technical field of transformer substation building formworks. The transformer substation column integrated fire-resistant non-dismantling formwork comprises a geopolymer formwork and bent anchor steel bars pre-buried in the geopolymer formwork. The geopolymer template is a hollow cylinder or prism with two open ends; one end of the bent anchor steel bar is pre-buried in the geopolymer template, and the other end of the bent anchor steel bar is hollow inwards; the geopolymer formwork is made of geopolymer concrete, and the geopolymer concrete comprises, by weight, 0.5-1% of carbon fibers. The transformer substation column integrated fire-resistant non-dismantling formwork can serve as a part of a permanent component in the construction process, dismantling is not needed, tedious construction and labor consumption caused by continuous formwork erecting and formwork dismantling in conventional concrete wet operation are avoided, the formwork and a concrete main body structure are jointly stressed in the later use process, and the bearing performance of the structure is improved. The cable is suitable for use scenes with high-strength and high-fire-resistance requirements in a complex environment of a transformer substation.

Description

Technical Field

[0001] The invention belongs to the technical field of transformer substation building formwork, and in particular relates to a transformer substation column integrated fire-resistant non-disassembly formwork and a construction method thereof. Background Art

[0002] High-strength concrete structures are mostly cast in the traditional way, which has complex construction technology and requires on-site processing of wooden formwork, followed by complex processes of supporting and removing formwork. The extensive use and loss of wooden formwork not only leads to waste of resources and environmental impact, but also leads to frequent quality problems of high-strength concrete after wooden formwork removal, such as pores, voids, honeycombs and pockmarks on the concrete surface, and high-strength concrete is prone to cracking after being exposed to fire. These problems not only affect the safety and durability of the structure, but also increase the workload of later repairs. At present, there are also non-disassembly formworks, such as the integrated formwork of fine steel fiber reinforced geopolymer concrete disclosed in the Chinese utility model patent with announcement number CN215760462U, which includes several formwork components, several formwork components are distributed in the vertical direction, and two adjacent formwork components are detachably connected, and the outer side of the formwork component located at the bottom is fixed with a pre-embedded component; the formwork components include vertically arranged plane formworks and right-angle formworks, and four plane formworks and right-angle formworks are provided, and four plane formworks and four right-angle formworks form a square tubular structure, and two adjacent plane formworks are detachably connected through the right-angle formworks; the integrated formwork does not need to be dismantled after pouring, and is formed integrally with the concrete column, eliminating the step of removing the formwork after pouring, and speeding up the construction speed. However, this type of non-disassembly formwork has the problems of complex construction process and poor strength or fire resistance when applied to substations. Summary of the invention

[0003] The technical problem to be solved by the present invention is: how to provide an integrated non-disassembly formwork for a substation column with good fire resistance and high compressive strength and flexural strength.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: an integrated fire-resistant non-disassembly formwork for a substation column, comprising a geopolymer formwork and a bent anchor steel bar pre-embedded in the geopolymer formwork; the geopolymer formwork is a column or prism with a hollow interior and openings at both ends; one end of the bent anchor steel bar is pre-embedded in the geopolymer formwork, and the other end is arranged toward the internal hollow; The geopolymer formwork is made of geopolymer concrete, and the geopolymer concrete includes 0.5-1% carbon fiber by weight.

[0005] The construction method of the above-mentioned integrated fire-resistant and non-dismantling formwork for substation columns includes the following steps: preparing geopolymer concrete according to the above-mentioned ratio in a workshop or production site, and using geopolymer concrete in combination with bent anchor steel bars to cast the fire-resistant and non-dismantling formwork; the fire-resistant and non-dismantling formwork does not need to be dismantled after use.

[0006] The beneficial effects of the present invention are as follows: the integrated fire-resistant and non-dismantling formwork for the substation column provided by the present invention is formed by connecting the geopolymer formwork through bent anchor steel bars. Since 0.5-1% of carbon fiber is added to the geopolymer concrete used to make the geopolymer formwork, the fire resistance, compressive strength and flexural strength of the obtained geopolymer formwork are effectively improved. The obtained fire-resistant and non-dismantling formwork can not only be used as a permanent component without removal, avoiding the need for continuous formwork and cumbersome construction, but also bears force together with the concrete main structure during later use, which can significantly improve the bearing capacity of the structure. It is especially suitable for scenes with high pressure requirements and high fire resistance requirements such as substations. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a structural schematic diagram of an integrated fire-resistant and non-disassembly formwork for a substation column according to a specific embodiment of the present invention; Figure 2 It is a structural schematic diagram of another angle of the integrated fire-resistant and non-disassembly formwork for a substation column according to a specific embodiment of the present invention; Figure 3 It is a graph of the compressive strength of carbon fiber geopolymer templates with different doping amounts according to a specific embodiment of the present invention; Figure 4 This is a graph showing the flexural strength of carbon fiber geopolymer templates with different doping amounts according to a specific embodiment of the present invention; Description of labels: 1. Bent anchor steel bars; 2. Geopolymer formwork. DETAILED DESCRIPTION

[0008] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0009] Please refer to Figure 1 as well as Figure 2 A fire-resistant non-disassembly formwork comprises a geopolymer formwork and a bent anchor steel bar embedded in the geopolymer formwork; the geopolymer formwork is a column or prism with a hollow interior and openings at both ends; one end of the bent anchor steel bar is embedded in the geopolymer formwork, and the other end is arranged toward the internal hollow; the geopolymer formwork is integrally formed; The geopolymer formwork is made by pouring geopolymer concrete, and the geopolymer concrete includes 0.5-1% carbon fiber by weight, preferably 0.75-1%.

[0010] From the above description, it can be seen that the beneficial effect of the present invention is that the integrated fire-resistant and non-removable formwork of the substation column provided by the present invention can be used as a permanent component without removal, avoiding the need for continuous formwork and cumbersome construction of demoulding. At the same time, the integrated fire-resistant and non-removable formwork of the substation column is subjected to force together with the concrete main structure during the later use process, thereby improving the bearing capacity of the structure. Due to the addition of a certain amount of carbon fiber and the fact that the geopolymer formwork is an integrated structure, there is no gap around the template of the substation column, and the external corrosive medium is not suitable for penetration and invasion, thereby significantly improving the compressive strength, flexural strength, durability (including seawater erosion resistance) and fire resistance of the fire-resistant and non-removable formwork. Due to the above characteristics, the fire-resistant and non-removable formwork provided by the present invention is particularly suitable for the construction of substations, including substations in coastal areas, and can meet the requirements of the substation due to electrical equipment and other reasons, the upper load is larger, the strength requirements of the components are higher, and the beam and column components of the substation need to meet the requirements of higher fire resistance due to the presence of oil-bearing electrical equipment.

[0011] The shape of the geopolymer formwork can be adjusted according to construction requirements, such as cylinder, triangular prism, quadrangular prism, pentagonal prism, etc. The geopolymer formwork is integrally formed, that is, an integrated formwork without joints, which can effectively resist the invasion of external corrosive media and improve the carbonation resistance and durability of the internal concrete.

[0012] Further, the geopolymer concrete includes granite powder, slag, metakaolin, melamine, water glass, sodium hydroxide, carbon fiber, river sand and water.

[0013] Further, the mass ratio of kaolin and slag is 4:6, 5:5 or 3:7. Further, the water-binder ratio of geopolymer concrete is 0.4-0.55, and the sand-binder ratio is 1.2-2.5, preferably 1.6-2.0. The mass ratio of water to slag and kaolin is the water-binder ratio. The ratio of river sand to gel material is the sand-binder ratio.

[0014] Furthermore, the modulus of water glass is 1 to 1.6.

[0015] From the above description, it can be seen that, unlike the use of general building components, in order to meet the requirements of high strength and high fire resistance of the substation, the strength, fire resistance and durability of the geopolymer formwork are improved by adding granite powder, adjusting the water-binder ratio and the sand-binder ratio, and adding 0.5-1% carbon fiber. Due to the ratio of the geopolymer concrete of the geopolymer formwork of the present invention, 0.5-1% carbon fiber needs to be added to achieve a significant performance improvement effect.

[0016] Furthermore, the geopolymer concrete comprises 0.3-0.6% melamine by weight.

[0017] From the above description, it can be seen that melamine is mainly used as a water reducing agent, while improving frost resistance, reducing construction difficulty and improving construction efficiency.

[0018] Further, the geopolymer concrete includes 6-10% sodium hydroxide by weight.

[0019] Furthermore, the geopolymer concrete includes 0.2-0.5% granite powder by weight.

[0020] Furthermore, the carbon fiber is any finished product available on the market, such as various carbon fibers produced by Toray.

[0021] The construction method of the above-mentioned integrated fire-resistant and non-dismantling formwork for substation columns includes the following steps: preparing geopolymer concrete according to the above-mentioned ratio in a workshop or production site, and using geopolymer concrete in combination with bent anchor steel bars to cast the integrated fire-resistant and non-dismantling formwork for substation columns; the integrated fire-resistant and non-dismantling formwork for substation columns is used as a formwork for casting high-strength reinforced concrete substation columns and does not need to be dismantled after use.

[0022] Please refer to Figure 1~2 , Embodiment 1 of the present invention is: An integrated fire-resistant and non-disassembly formwork for a transformer substation column comprises a rectangular geopolymer formwork and bent anchor steel bars embedded in the geopolymer formwork; the geopolymer formwork is a rectangular parallelepiped with a hollow interior and openings at both ends; one end of the bent anchor steel bar is embedded in the geopolymer formwork, and the other end is disposed toward the hollow interior; Geopolymer forms are made of geopolymer concrete; In terms of weight percentage, the geopolymer concrete is composed of the following components: 0.2% granite powder, 0.48% slag, 0.32% kaolin, 0.3% melamine, water glass with a modulus of 1.6, 6% sodium hydroxide, 0.75% carbon fiber (Toray T700), river sand and water; the water-binder ratio of the geopolymer concrete is 0.45, and the sand-binder ratio is 1.8; the mass ratio of kaolin and slag is 4:6.

[0023] The construction method of the above-mentioned fire-resistant non-disassembly formwork includes the following steps: preparing geopolymer concrete according to the above-mentioned ratio in a workshop or production site, and using geopolymer concrete in combination with bent anchor steel bars to cast the fire-resistant non-disassembly formwork; the fire-resistant non-disassembly formwork does not need to be dismantled after use.

[0024] Embodiment 2 of the present invention is: The difference between Example 2 and Example 1 is that the added amount of carbon fiber is 0.5%.

[0025] Embodiment 3 of the present invention is: The difference between Example 3 and Example 1 is that the addition amount of carbon fiber is 1%.

[0026] Embodiment 4 of the present invention is: The only difference between Example 4 and Example 1 is that the added amount of carbon fiber is 1.5%.

[0027] Embodiment 5 of the present invention is: The difference between Example 5 and Example 1 is that the composition of the geopolymer concrete is different. The geopolymer concrete of Example 5 is composed of the following components by weight percentage: 0.3% granite powder, 0.48% slag, 0.32% kaolin, 0.6% melamine, water glass with modulus 1, 10% sodium hydroxide, 1% carbon fiber (Toray T700), river sand and water; the water-binder ratio of the geopolymer concrete is 0.5, the sand-binder ratio is 1.8, and the mass ratio of kaolin and slag is 5:5.

[0028] Embodiment 5 of the present invention is: The difference between Example 6 and Example 1 is that the composition of the geopolymer concrete is different. The geopolymer concrete of Example 5 is composed of the following components by weight percentage: 0.5% granite powder, 0.48% slag, 0.32% kaolin, 0.5% melamine, water glass with a modulus of 1.2, 8% sodium hydroxide, 0.8% carbon fiber (Toray T700), river sand and water; the water-binder ratio of the geopolymer concrete is 0.55, the sand-binder ratio is 1.8, and the mass ratio of kaolin and slag is 3:7.

[0029] Comparative Example 1 is: The difference between Comparative Example 1 and Example 1 is only that the addition amount of carbon fiber is 0%.

[0030] Comparative Example 2 is: The difference between Comparative Example 2 and Example 1 is that the addition amount of carbon fiber is 0.25%.

[0031] The compressive strength and flexural strength of the geopolymer formwork obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were tested on the 7th, 14th and 28th days after manufacture. The test was carried out in accordance with the "Concrete Physical and Mechanical Properties Test Method Standard" GB50081-2019. The standard concrete compressive performance cube test block adopts a 150mm×150mm×150mm test block, and the standard test piece for the concrete flexural performance test should be a 150mm×150mm×600mm test piece. There are three compressive strength and flexural strength test blocks in each group. The results are shown in Tables 1 and 2, and Figure 3 and Figure 4 shown.

[0032] The temperature resistance test of the geopolymer template obtained in Example 1 was carried out 28 days after it was made. The results are shown in Table 3.

[0033] Table 1

[0034] Table 2

[0035] Table 3

[0036] In summary, the integrated fire-resistant and non-disassembly formwork for substation columns provided by the present invention has the following advantages: (1) Suitable for substation column construction in substations, with good high temperature resistance, high compressive strength and flexural strength; (2) The template is an integrated structure without joints, and there is no gap around the template, so external corrosive media are not easy to penetrate and invade; (3) There is no need to remove the formwork. It can be used as part of a permanent component and bear the load together with the main concrete structure, further increasing the bearing capacity of the structure. At the same time, it greatly reduces the construction difficulty and the various costs required for modeling and removing the formwork, thereby improving construction efficiency.

[0037] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An integrated fire-resistant and non-dismantling formwork for a substation column, characterized in that: It comprises a geopolymer template and a bent anchor steel bar embedded in the geopolymer template; the geopolymer template is a column or prism with a hollow interior and openings at both ends; one end of the bent anchor steel bar is embedded in the geopolymer template, and the other end is arranged toward the hollow interior; The geopolymer formwork is made of geopolymer concrete, and the geopolymer concrete includes 0.5-1% carbon fiber by weight.

2. The integrated fire-resistant and non-dismantling formwork for substation columns according to claim 1 is characterized in that: The geopolymer concrete comprises granite powder, slag, metakaolin, melamine, water glass, sodium hydroxide, carbon fiber, river sand and water.

3. The integrated fire-resistant and non-dismantling formwork for substation columns according to claim 2 is characterized in that: The mass ratio of the metakaolin to the slag is 4:6, 5:5 or 3:

7.

4. The integrated fire-resistant and non-dismantling formwork for substation columns according to claim 2 is characterized in that: The water-to-binder ratio of the geopolymer concrete is 0.4-0.

55.

5. The integrated fire-resistant and non-dismantling formwork for substation columns according to claim 2 is characterized in that: The modulus of the geopolymer water glass is 1 to 1.

6.

6. The integrated fire-resistant and non-dismantling formwork for substation columns according to claim 1 is characterized in that: In terms of weight percentage, the sand-to-cement ratio of the geopolymer concrete is 1.2-2.

5.

7. The integrated fire-resistant and non-dismantling formwork for substation columns according to claim 1 is characterized in that: The geopolymer concrete comprises 0.3-0.6% melamine by weight.

8. The integrated fire-resistant and non-dismantling formwork for substation columns according to claim 1 is characterized in that: The geopolymer concrete comprises 6-10% sodium hydroxide by weight.

9. The integrated fire-resistant and non-dismantling formwork for substation columns according to claim 1 is characterized in that: The geopolymer concrete includes 0.2-0.5% granite powder by weight.

10. A construction method for the integrated fire-resistant non-disassembly formwork for a substation column according to any one of claims 1 to 9, characterized in that: The method comprises the following steps: preparing geopolymer concrete according to the above proportion in a workshop or production site, and casting a geopolymer formwork by using the geopolymer concrete in combination with bent anchor steel bars; and the geopolymer formwork does not need to be dismantled after use.

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