Construction method of concrete bottom plate

Abstract

The invention relates to the field of concrete building construction, and particularly discloses a construction method of a concrete bottom plate, which comprises the following steps of: dividing mass concrete into at least one part, sequentially constructing, segmenting each part in rows, dividing the part into a plurality of bottom plate blocks, sequentially constructing a plurality of inclined sections, and performing block pouring according to the construction sequence. The temperature difference in the mass concrete poured at a time can be reduced, the crack risk caused by temperature stress and shrinkage is reduced, generation of a large number of long and deep cracks is avoided, and the excellent construction quality of the mass concrete structure is achieved.

Description

Technical Field

[0001] The invention relates to the field of concrete building construction, and in particular to a construction method of a concrete bottom plate. Background Art

[0002] The concrete floor refers to the lower edge of the box section. It is the main working part that bears positive and negative bending moments and plays an important role in structural engineering. The construction process of the concrete floor is a complex process that requires precise control. The conventional steps include preparation, foundation treatment, reinforcement engineering, concrete pouring, maintenance and demoulding. With the rapid development of the construction industry, super-large buildings and large-span structures are increasing, and large-volume concrete floor structures have gradually been widely used.

[0003] At present, there is no unified definition of mass concrete. It is generally believed that during the concrete pouring process, if the concrete volume is large enough to cause significant temperature gradients and stresses inside the concrete, then such mass concrete has the risk of the temperature difference between the inside and outside of the concrete exceeding the safe range due to the heat release of the hydration reaction, which is sufficient to cause concrete crack defects. For example, a cast structure with a single structure of more than 1,000 cubic meters is a typical mass concrete.

[0004] A certain area has high temperature, low humidity and little rain all year round, and the on-site construction conditions are poor. Due to the rapid evaporation of water or thermal expansion, the large-volume concrete base plate structure is constructed using the conventional one-time pouring construction method, which will cause a large number of deep and long cracks in the concrete base plate, seriously affecting the construction quality.

[0005] Therefore, it is of great significance to develop a construction method for large-volume concrete floor structures suitable for special high-temperature environments to avoid the occurrence of a large number of deep and long cracks. Summary of the invention

[0006] The purpose of the present invention is to provide a method for constructing a concrete base plate in view of the technical problem that a large number of deeper and longer cracks are easily formed in the constructed concrete structure when constructing a large-volume concrete base plate under special natural conditions of high temperature in the prior art. The large-volume concrete is divided into at least one part for sequential construction, and then each part is divided into rows and sections to be divided into a plurality of base plates, and a plurality of inclined sections are sequentially constructed. By casting the blocks in this construction sequence, the temperature difference inside the large-volume concrete cast at one time can be reduced, the risk of cracks caused by temperature stress and shrinkage can be reduced, the generation of a large number of longer and deeper cracks can be avoided, and a better construction quality of the large-volume concrete structure can be achieved.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is:

[0008] A construction method for a concrete base plate comprises the following steps:

[0009] The concrete base plate is divided into at least one part, and each part of the concrete base plate is constructed in turn during construction. Each part of the concrete base plate is constructed according to the following method:

[0010] Each part of the concrete slab is designed for block construction: the concrete slab is divided into a number of rows, namely the 1st row, the 2nd row, ... the i-th row; each row is divided into the 1st column, the 2nd column, ... the j-th column from one end to the other; i and j are both integers ≥ 2;

[0011] S1, pouring the bottom plate positioned in the first row and first column to complete the construction of the first oblique section;

[0012] S2, pouring the bottom plate positioned in the first row and second column, pouring the bottom plate positioned in the second row and first column, and completing the construction of the second oblique section;

[0013] S3, pouring the bottom plate positioned in the 3rd column of the 1st row, pouring the bottom plate positioned in the 2nd column of the 2nd row, pouring the bottom plate positioned in the 1st column of the 3rd row, and completing the construction of the third oblique section;

[0014] Complete the pouring of all the bottom slabs of each section of concrete bottom slab according to the same construction sequence rules as the S1-S3 diagonal sections;

[0015] Among them, when the oblique section is constructed to the designed width of the i-th row of each part of the concrete bottom plate or the designed length of the j-th column of each part of the concrete bottom plate, it will stop and the construction of the bottom plate block of the next column or row will be postponed.

[0016] The present invention provides a construction method for a concrete base plate, which divides a large volume of concrete into at least one part for sequential construction, and then divides each part into rows and sections to be divided into a plurality of base plates, and sequentially constructs a plurality of oblique sections. By casting in blocks in this construction sequence, the temperature difference inside the large volume of concrete cast at one time can be reduced, the risk of cracks caused by temperature stress can be reduced, cracks caused by shrinkage can be effectively controlled, and the construction quality can be improved.

[0017] Furthermore, each base plate is constructed by horizontal partitioning, vertical layering, and diagonal segmentation.

[0018] Furthermore, the specific construction method of each bottom plate includes the following steps: vertically, the bottom plate is divided into a plurality of layers, from bottom to top, the first layer, the second layer, ... the mth layer;

[0019] Each layer is divided into a number of columns in the length direction, which are the 1st column, the 2nd column, and the nth column from one end to the other; each layer is divided into a number of rows in the width direction, which are the 1st row, the 2nd row, and the rth row from one end to the other; wherein m, n, and r are all positive integers ≥ 2;

[0020] A1, pouring the blocks located in the first row and first column of the first layer;

[0021] A2, pouring the block located in the first row and second column of the first layer, and pouring the block located in the second row and first column of the first layer;

[0022] A3, pouring the blocks located in the first row and first column of the second layer;

[0023] A4, pouring the block located in the first row and third column of the first layer, pouring the block located in the second row and second column of the first layer, and pouring the block located in the third row and first column of the first layer;

[0024] A5. Cast the block located in the first row and second column of the second layer, and cast the block located in the second row and first column of the second layer;

[0025] A6. Cast the blocks located in the first row and first column of the third layer;

[0026] A7, pouring the block located in the 4th column of the 1st row in the 1st layer, pouring the block located in the 3rd column of the 2nd row in the 1st layer, pouring the block located in the 2nd column of the 3rd row in the 1st layer, pouring the block located in the 1st column of the 4th row in the 1st layer is fast;

[0027] A8, pouring the block located in the first row and third column of the second layer, pouring the block located in the second row and second column of the second layer, pouring the block located in the third row and first column of the second layer;

[0028] A9, pouring the block located in the first row and second column of the third layer, and pouring the block located in the second row and first column of the third layer;

[0029] A10, pouring the blocks positioned in the first row and first column of the fourth layer;

[0030] …

[0031] Complete the pouring of the entire base plate according to the same construction sequence rules as A1-A10;

[0032] Before pouring the blocks, the adjacent blocks need to be demoulded;

[0033] Among them, when the construction reaches the designed width of the rth row of the bottom plate, the designed length of the nth column of the bottom plate, or the designed height of the mth layer of the bottom plate, it stops and the construction of the next layer, the next row, or the next column is postponed.

[0034] Each base plate is constructed by horizontal partitioning, vertical stratification, and oblique segmentation, which can better adapt to the high temperature difference environment and cast large-volume concrete structures, better avoid the occurrence of large cracks and improve the quality of the concrete base plate.

[0035] Furthermore, the thickness of each layer in the bottom plate does not exceed 40 cm.

[0036] Furthermore, before A1, it also includes clearing debris from the designed construction location of the base plate and measuring and laying out the lines at the designed construction location of the base plate.

[0037] Furthermore, the interval between pouring concrete of two adjacent blocks is no more than 7 days.

[0038] Furthermore, before pouring each block, the concrete surface of the adjacent blocks is roughened.

[0039] Furthermore, the casting method of the block body comprises the following steps:

[0040] Tie the steel cage at the designed position of the block;

[0041] Install concrete pouring formwork and clean the pouring space from water, dust and / or debris;

[0042] Pour concrete into the formwork and let it stand;

[0043] Among them, the temperature of concrete entering the mold is controlled within 32°C, and the time from concrete mixing to final pouring is controlled within 90 minutes.

[0044] Furthermore, when pouring concrete, vibration is performed from the top of the formwork.

[0045] Furthermore, the time of each vibration is controlled within 15-20 seconds, the distance between the vibration points is between 40-50 cm, and the vibrating rod is inserted into the lower layer of concrete by 10-15 cm.

[0046] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0047] 1. The present invention provides a method for constructing a concrete base plate, in which a large volume of concrete is divided into at least one part for sequential construction, and then each part is divided into multiple bottom plates for sequential construction of multiple oblique sections. By casting in blocks in this construction sequence, the temperature difference inside the large volume of concrete cast at one time can be reduced, the risk of cracks caused by temperature stress and shrinkage can be reduced, and the occurrence of a large number of longer and deeper cracks can be avoided, thereby achieving better construction quality of large volume concrete structures.

[0048] 2. The present invention provides a construction method for a concrete base plate. The entire concrete base plate is constructed in parts, and each part of the concrete base plate is further constructed in a plurality of base plate blocks. Each base plate is cast in a vertical layered, oblique segmented, and horizontally partitioned manner. This casting method can ensure the quality and strength of the concrete structure, effectively avoid shrinkage and cracking of the concrete, and can check the quality and strength of the concrete layer by layer during the construction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is an aerial photo of the water intake pump station in Example 1.

[0050] Figure 2 This is a construction sequence diagram of the bottom plate of the bottom plate structure of the water intake pump station in Example 1.

[0051] Figure 3 This is a schematic diagram of the bottom plate segmentation and construction sequence of the concrete bottom plate in other embodiments provided by the present invention.

[0052] Figure 4 for Figure 2 Schematic diagram of some construction blocks and some construction sequence of each base plate.

[0053] Figure 5 for Figure 2 Schematic diagram of the construction sequence of each base plate.

[0054] Icon: 1- base plate; 11- sub-blocks. DETAILED DESCRIPTION

[0055] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0056] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0057] Unless otherwise specified, in the description of the specific embodiments of the present invention, the terms indicating the orientation or position relationship such as "up", "down", "left", "right", "center", "inside", "outside", etc. are all expressions based on the orientation or position relationship shown in the drawings, or the orientation or position relationship in which the invented product / equipment / device is placed when it is usually used. These terms of orientation or position relationship are only for the convenience of describing the scheme of the present invention or simplifying the description in the specific embodiments, so as to facilitate the technicians to quickly understand the scheme, and do not indicate or imply that a specific device / component / element must have a specific orientation, or be constructed and operated in a specific position relationship, and therefore cannot be understood as a limitation on the present invention.

[0058] In addition, if the terms "horizontal", "vertical", "overhanging", "parallel" and the like appear, it does not mean that the corresponding devices / components / elements are required to be absolutely horizontal or vertical or overhanging or parallel, but may be slightly tilted or have deviations. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but may be slightly tilted. Alternatively, it can be simplified to mean that the corresponding devices / components / elements are set in directions such as "horizontal", "vertical", "overhanging", "parallel", etc., and can have an error / deviation of ±10% relative to the corresponding direction setting, more preferably an error / deviation within ±8%, more preferably an error / deviation within ±6%, more preferably an error / deviation within ±5%, and more preferably an error / deviation within ±4%. As long as the corresponding device / component / element is within the error / deviation range, it can still achieve its role in the scheme of the present invention.

[0059] In addition, the expressions “first”, “second”, “third”, etc. that appear in the terms are merely descriptions used to distinguish the same or similar components and should not be understood as emphasizing or implying the relative importance of specific components.

[0060] In addition, in the description of the embodiments of the present invention, "several", "plurality" and "a number" represent at least 2. It can be any number such as 2, 3, 4, 5, 6, 7, 8, 9, and even more than 9.

[0061] In addition, in the description of the technical solution of the present invention, unless otherwise clearly specified / defined / restricted, the terms "set", "install", "connect", "connected", "provided with", "laid", and "arranged" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection, and can be welding, riveting, bolting, threading, and other commonly used connection means in the field. This connection can be a mechanical connection, an electrical connection, or a communication connection; it can be a direct connection, or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0062] Example

[0063] like Figure 1As shown in the figure, the pump station of the JCPDI seawater cooling project (Phase I) is an onshore reinforced concrete structure, which is arranged in an east-west direction as a whole, and the structural axis is perpendicular to the coastline. The water intake pump station consists of a sedimentation tank, a filter station, a transition section, a pump station flow channel and a pump cabin. The total length of the pump station is 108.6m, the height is 23m, the sedimentation tank and filter station are 28m wide, the total width of the pump station flow channel area is 38.7m, and the concrete volume is about 26,000 cubic meters (excluding the upper electrical room, control room and motor hall). The concrete walls of the water intake pump station can be divided into two categories according to their location: outer walls and inner walls. The thickness of the outer walls in areas above -1.5m above sea level is 1m. Below -1.5m above sea level, the thickness of the outer walls on the north and south sides of the sedimentation tank and the filtration station is 2.5m. The thickness of the outer walls on the west and east sides of the pump station and the transition section, as well as the outer walls on the north and south sides of the pump station flow channel is 1.5m. The thickness of the diversion wall of the internal flow channel of the pump station is 0.9m, and the thickness of the sedimentation tank partition wall, the filtration station diversion wall and the sand retaining wall in the flow channel area of ​​the pump station is 1m.

[0064] The on-site construction conditions are as follows:

[0065] Temperature: The average monthly temperature is 28-36℃, and the highest temperature in summer can reach 50℃.

[0066] Rainfall: The average annual rainfall is about 155 mm, with more rainfall in January, August, and October-December. Based on field experience, there is a possibility of sudden storms. On July 29, 2016 alone, the rainfall reached 104.4 mm.

[0067] Wind speed: Mainly west and southwest winds, with an average wind speed of 4-6m / s and gusts of 9-12m / s. Sudden and strong winds may occur in summer. According to on-site experience, the maximum wind speed reached 42m / s (level 13) on the evening of July 29, 2016.

[0068] For large-volume concrete structures such as the water pump concrete base plate, it should be noted that cracks are very likely to appear on the concrete base plate during the construction phase, affecting the quality and safety of the concrete base plate.

[0069] The main reasons for cracks in large concrete structures during the construction phase include:

[0070] (1) Adiabatic temperature rise caused by hydration heat: It is related to the amount of cement and the type of cement in the unit volume of concrete, and increases exponentially with the age of concrete, generally reaching the final adiabatic temperature rise in about 10 days. However, due to the natural heat dissipation of the structure, the actual maximum temperature inside the concrete mostly occurs 3 to 5 days after the concrete is poured.

[0071] (2) Internal temperature of concrete = pouring temperature + hydration heat adiabatic temperature rise - structural heat dissipation cooling The higher the outside temperature, the higher the pouring temperature of concrete; if the outside temperature drops, the cooling range of concrete will increase. Especially when the temperature drops suddenly, the temperature gradient inside and outside the concrete will increase, which is extremely unfavorable for large-volume concrete.

[0072] (3) Concrete shrinkage is mainly caused by the evaporation of excess water in the concrete, which causes the concrete volume to shrink during drying. (If this shrinkage is constrained, shrinkage stress will be generated.) Concrete drying shrinkage is reversible to a large extent.

[0073] (4) In addition to drying shrinkage, concrete also has carbonation deformation. That is, CO2 in the air reacts with Ca(OH)2 in the concrete cement to form calcium carbonate CaCO3, which releases bound water and causes concrete to shrink.

[0074] This project is located in the JZ area with high temperature, low humidity and little rain all year round. The site conditions are harsh and the control of concrete under the on-site construction conditions is relatively difficult. The main difficulties are as follows:

[0075] Rapid evaporation of moisture: High temperature will accelerate the evaporation of moisture in concrete, causing early shrinkage of concrete and prone to cracks.

[0076] Thermal expansion: High temperatures will cause the internal temperature of the concrete to rise, causing volume expansion, which will produce thermal stress after cooling and lead to cracks.

[0077] Changes in material properties:

[0078] Changes in material properties will result in data monitoring of concrete durability, concrete strength development and on-site temperature control.

[0079] In order to adapt to the construction of concrete structures in this special environment, temperature control measures are required for large-volume concrete, including:

[0080] Temperature before entering the mold: Controlling the temperature of concrete before entering the mold can effectively slow down the early hydration heat release and prevent cracks caused by rapid temperature changes. Temperature detection should be carried out before and after mixing and pouring. The temperature after mixing should be controlled within 25°C and the temperature before entering the mold should be controlled within 32°C.

[0081] Maximum temperature: The maximum temperature inside the concrete has a direct impact on its long-term performance and durability. Excessive temperature will aggravate thermal stress and cause cracks. Use temperature sensors for real-time monitoring to ensure that the maximum temperature does not exceed 70°C.

[0082] Maximum temperature rise: Excessive temperature rise will increase the internal temperature difference, causing thermal stress and cracking. Check the temperature regularly during pouring and curing to ensure that the temperature rise is controlled within the range of 20-25℃.

[0083] Temperature difference between inside and outside: Controlling the temperature difference between inside and outside can reduce the occurrence of surface cracks and ensure the safety of the structure. Use temperature sensors for real-time monitoring to ensure that the temperature difference between inside and outside does not exceed 20°C.

[0084] Since the base plate area of ​​the water pump is large, under such special natural conditions, if the pouring is completed in one go, or if it is poured in blocks in a random manner, the temperature difference of the concrete base plate structure will be large, and a large number of cracks will easily appear.

[0085] To this end, the present invention provides a construction method for a concrete base plate. By pouring large-volume concrete in blocks according to the design plan, the temperature difference inside the large-volume concrete poured at one time can be reduced, the risk of cracks caused by temperature stress can be reduced, cracks caused by shrinkage can be effectively controlled, and the construction quality can be improved.

[0086] Combined with the ash discharge efficiency and pouring speed of the on-site mixing station, the pump station base plate is divided into 12 sections for pouring. The specific construction process is as follows:

[0087] A construction method for a concrete base plate comprises the following steps:

[0088] like Figure 2 As shown in the figure, the concrete base plate is divided into two parts: Figure 2 During the construction of Part A and Part B, the construction of each part of the concrete base plate is carried out in sequence. Each part of the concrete base plate is constructed according to the following method:

[0089] Construction of concrete base slab of Part A:

[0090] like Figure 2 As shown, the concrete base plate of part A is designed for block construction and divided into two rows and three columns.

[0091] S1, pouring the bottom plate positioned in the first row and first column to complete the construction of the first oblique section;

[0092] S2, pouring the bottom plate positioned in the first row and second column, pouring the bottom plate positioned in the second row and first column, and completing the construction of the second oblique section;

[0093] S3, such as Figure 2 As shown, there are two lines in total, such as Figure 2 As shown, the bottom plate positioned in the second row and second column can be cast first, and then the bottom plate positioned in the first row and third column can be cast. When the inclined section is constructed to the designed length or width of each concrete bottom plate, it is stopped and the construction of the next inclined section is postponed. The casting of each concrete bottom plate is completed according to the same construction sequence rules of the inclined sections S1-S3; the construction sequence of ①-⑥ in part A is realized.

[0094] Figure 2In the design, the concrete base plate of part B is divided into three rows and two columns. The same construction sequence rules as part A are adopted to complete ⑦ to construction sequence.

[0095] In some embodiments, the structure of a portion of the concrete floor is as follows Figure 3 As shown, it is divided into four rows and four columns.

[0096] S1, pouring the bottom plate 1 positioned in the first row and first column to complete the construction of the first oblique section;

[0097] S2, pouring the bottom plate 1 positioned in the first row and second column, pouring the bottom plate 1 positioned in the second row and first column, completing the construction of the second oblique section;

[0098] S3, pouring the bottom plate 1 positioned in the 3rd column of the 1st row, pouring the bottom plate 1 positioned in the 2nd column of the 2nd row, pouring the bottom plate 1 positioned in the 1st column of the 3rd row, and completing the construction of the third oblique section;

[0099] S4, pouring the bottom plate 1 positioned in the 4th column of the 1st row, pouring the bottom plate 1 positioned in the 3rd column of the 2nd row, pouring the bottom plate 1 positioned in the 2nd column of the 3rd row, pouring the bottom plate 1 positioned in the 1st column of the 4th row, and completing the construction of the fourth oblique section;

[0100] S5, pouring the bottom plate 1 positioned in the 2nd row and the 4th column, pouring the bottom plate 1 positioned in the 3rd row and the 3rd column, pouring the bottom plate 1 positioned in the 4th row and the 2nd column, and completing the construction of the fifth oblique section;

[0101] S6, pouring the bottom plate 1 positioned in the 3rd row and the 4th column, pouring the bottom plate 1 positioned in the 4th row and the 3rd column to complete the construction of the sixth oblique section;

[0102] S7, pouring the bottom plate 1 positioned in the 4th row and 4th column, completing the construction of the seventh oblique section.

[0103] Specifically, Figure 4 and Figure 5 As shown, each bottom plate 1 is constructed by horizontal partitioning, vertical layering, and oblique segmentation, which specifically includes the following steps:

[0104] In the vertical direction, the bottom plate 1 is divided into four layers, which are the first layer, the second layer, the third layer and the fourth layer from bottom to top.

[0105] Each layer is divided into 5 columns in the length direction, from left to right, they are the 1st column, the 2nd column, the 3rd column, the 4th column, and the 5th column.

[0106] Each layer is divided into 4 rows in the width direction, which are row 1, row 2, row 3, and row 4 from bottom to top.

[0107] A1, pouring the block 11 located in the first row and first column of the first layer;

[0108] A2, pouring the block body 11 positioned in the first row and second column of the first layer, pouring the block body 11 positioned in the second row and first column of the first layer;

[0109] A3, pouring the block 11 located in the first row and first column of the second layer;

[0110] A4, pouring the block body 11 positioned in the first row and third column of the first layer, pouring the block body 11 positioned in the second row and second column of the first layer, and pouring the block body 11 positioned in the third row and first column of the first layer;

[0111] A5, pouring the block body 11 positioned in the first row and second column of the second layer, pouring the block body 11 positioned in the second row and first column of the second layer;

[0112] A6, pouring the block 11 located in the first row and first column of the third layer;

[0113] A7, pouring the block 11 positioned in the 1st row and 4th column of the first layer, pouring the block 11 positioned in the 2nd row and 3rd column of the first layer, pouring the block 11 positioned in the 3rd row and 2nd column of the first layer, pouring the block 11 positioned in the 4th row and 1st column of the first layer;

[0114] A8, pouring the block body 11 positioned in the first row and third column of the second layer, pouring the block body 11 positioned in the second row and second column of the second layer, and pouring the block body 11 positioned in the third row and first column of the second layer;

[0115] A9, pouring the block body 11 positioned in the first row and second column of the third layer, pouring the block body 11 positioned in the second row and first column of the third layer;

[0116] A10, pouring the block 11 located in the first row and first column of the fourth layer;

[0117] …

[0118] Complete the pouring of the entire base plate 1 according to the same construction sequence rules as A1-A10;

[0119] Before casting the block body 11, the block bodies 11 at adjacent positions need to be demolded;

[0120] When the construction reaches the designed width of the rth row of the bottom plate 1, the designed length of the nth column of the bottom plate 1, or the designed height of the mth layer of the bottom plate 1, the construction is stopped and the construction of the next layer, row, or column is continued.

[0121] Specific as Figure 5 As shown, it is divided into 80 blocks, which are constructed in ascending numerical order.

[0122] In some embodiments, before A1, the process also includes clearing debris from the designed construction location of the base plate and measuring and laying out lines at the designed construction location of the base plate.

[0123] In some embodiments, the interval between the concrete pouring of two adjacent blocks 11 is no more than 7 days. If the concrete pouring interval is controlled within a reasonable time, the connectivity between the two blocks will be better and no cracks will occur.

[0124] In some embodiments, before pouring each block 11, the concrete surfaces of adjacent blocks 11 are roughened.

[0125] In some embodiments, the casting method of the block body 11 includes the following steps:

[0126] Tie the steel cage at the designed position of the block 11;

[0127] Install concrete pouring formwork and clean the pouring space from water, dust and / or debris;

[0128] Pour concrete into the formwork and let it stand;

[0129] Among them, the temperature of concrete entering the mold is controlled within 32°C, and the time from concrete mixing to final pouring is controlled within 90 minutes.

[0130] In some embodiments, the thickness of each layer in the bottom plate does not exceed 40 cm. The concrete is poured using a pump truck with an arm length of 56 m. The concrete should be poured in layers, and the thickness of each layer should not exceed 40 cm. The pouring time between layers should not be too long to avoid cold joints. The entire pouring process should be continuous and not interrupted. At the same time, it should be noted that the pouring speed should be controlled to be no more than 2 m / h to prevent the template from bearing too much concrete side pressure in a short period of time.

[0131] In some embodiments, when pouring concrete, vibration is performed from the top of the formwork. During the concrete construction process, construction personnel stand on the operating platform at the top of the formwork to perform vibration operations. A 50-type inserted vibrator is used for vibration, and the time of each vibration is controlled within 15-20 seconds, and the distance between the vibration points is between 40-50cm. During vibration, the vibrator should be inserted into the lower layer of concrete by 10-15cm to ensure the effective combination of the upper and lower layers of concrete. At the same time, care should be taken to avoid steel bars, embedded parts, truncated cone nuts and embedded anchor rods. The minimum spacing between the vibrator and the side formwork is controlled at 5-10cm, and the side formwork must not be touched. The vibrator should be inserted quickly and pulled out slowly, and vibrated until the concrete surface is flat, without slurry or bubbles, and no vibration or over-vibration is allowed. It is strictly forbidden to add water to the concrete during the pouring process. If the concrete is found to have poor workability, the concrete tanker should rotate 5 times at a uniform speed, and then take other measures to strengthen vibration and improve workability.

[0132] During the concrete pouring period, arrange personnel to regularly inspect the formwork, paying special attention to the bolt connection and whether there is leakage in the formwork. If the above problems occur, notify the formwork workers in time to tighten or seal them.

[0133] Upon investigation, it was found that the width of the cracks was less than 0.05mm and the crack depth was relatively shallow. These were cracks formed due to water loss and shrinkage of the hardened concrete during the drying process. The repairs were carried out according to the concrete repair plan reported to the owner and the overall quality was controllable.

[0134] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for constructing a concrete floor, characterized in that: The following steps are involved: The concrete base plate is divided into at least one part, and each part of the concrete base plate is constructed in turn during construction. Each part of the concrete base plate is constructed according to the following method: Each part of the concrete slab is designed for block construction: the concrete slab is divided into a number of rows, namely the 1st row, the 2nd row, ... the i-th row; each row is respectively the 1st column, the 2nd column, ... the j-th column from one end to the other; i and j are both integers ≥ 2; S1, pouring the bottom plate positioned in the first row and first column to complete the construction of the first oblique section; S2, pouring the bottom plate positioned in the first row and second column, pouring the bottom plate positioned in the second row and first column, and completing the construction of the second oblique section; S3, pouring the bottom plate positioned in the 3rd column of the 1st row, pouring the bottom plate positioned in the 2nd column of the 2nd row, pouring the bottom plate positioned in the 1st column of the 3rd row, and completing the construction of the third oblique section; Complete the pouring of all the bottom slabs of each section of concrete bottom slab according to the same construction sequence rules as the S1-S3 diagonal sections; Among them, when the oblique section is constructed to the designed width of the i-th row of each part of the concrete bottom plate or the designed length of the j-th column of each part of the concrete bottom plate, it will stop and the construction of the bottom plate block of the next column or row will be postponed.

2. The construction method of the concrete floor according to claim 1, characterized in that: Each base plate is constructed by horizontal partitioning, vertical layering and diagonal segmentation.

3. The construction method of the concrete floor according to claim 2, characterized in that: The specific construction method of each bottom plate comprises the following steps: in the vertical direction, the bottom plate is divided into a plurality of layers, which are the 1st layer, the 2nd layer, ... the mth layer from bottom to top; each layer is divided into a plurality of columns in the length direction, which are the 1st column, the 2nd column, ... the nth column from one end to the other; each layer is divided into a plurality of rows in the width direction, which are the 1st row, the 2nd row, ... the rth row from one end to the other; wherein m, n and r are all positive integers ≥ 2; A1, pouring the blocks located in the first row and first column of the first layer; A2, pouring the block located in the first row and second column of the first layer, and pouring the block located in the second row and first column of the first layer; A3, pouring the blocks located in the first row and first column of the second layer; A4, pouring the block located in the first row and third column of the first layer, pouring the block located in the second row and second column of the first layer, and pouring the block located in the third row and first column of the first layer; A5. Cast the block located in the first row and second column of the second layer, and cast the block located in the second row and first column of the second layer; A6. Cast the blocks located in the first row and first column of the third layer; A7, pouring the block located in the 4th column of the 1st row in the 1st layer, pouring the block located in the 3rd column of the 2nd row in the 1st layer, pouring the block located in the 2nd column of the 3rd row in the 1st layer, pouring the block located in the 1st column of the 4th row in the 1st layer is fast; A8, pouring the block located in the first row and third column of the second layer, pouring the block located in the second row and second column of the second layer, pouring the block located in the third row and first column of the second layer; A9, pouring the block located in the first row and second column of the third layer, and pouring the block located in the second row and first column of the third layer; A10, pouring the block located in the first row and first column of the fourth layer; …… Complete the pouring of the entire base plate according to the same construction sequence rules as A1-A10; Before pouring the blocks, the adjacent blocks need to be demoulded; Among them, when the construction reaches the designed width of the rth row of the bottom plate, the designed length of the nth column of the bottom plate, or the designed height of the mth layer of the bottom plate, it stops and the construction of the next layer, the next row, or the next column is postponed.

4. The construction method of the concrete floor according to claim 3, characterized in that: The thickness of each layer in the bottom plate shall not exceed 40cm.

5. The method for constructing a concrete floor according to claim 3, characterized in that: Before A1, it also includes clearing debris at the designed location for base plate construction and measuring and laying out at the designed location for base plate construction.

6. The construction method of the concrete floor according to claim 3, characterized in that: The interval between pouring concrete of two adjacent blocks shall not exceed 7 days.

7. The method for constructing a concrete floor slab according to claim 3, characterized in that: Before pouring each block, the concrete surface of the adjacent blocks is roughened.

8. The method for constructing a concrete floor according to any one of claims 2 to 7, characterized in that: The method for casting the block body comprises the following steps: Tie the steel cage at the designed position of the block; Install concrete pouring formwork and clean the pouring space from water, dust and / or debris; Pour concrete into the formwork and let it stand; Among them, the temperature of concrete entering the mold is controlled within 32°C, and the time from concrete mixing to final pouring is controlled within 90 minutes.

9. The method for constructing a concrete floor slab according to claim 8, characterized in that: When pouring concrete, vibrate from the top of the formwork.

10. The method for constructing a concrete floor slab according to claim 9, characterized in that: The time of each vibration is controlled within 15-20 seconds, the distance between the vibration points is between 40-50cm; the vibrating rod is inserted 10-15cm into the lower layer of concrete.

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