A strength and elastic modulus design method for compression casting of seawater sand concrete

Abstract

The present application discloses a design method for the strength and elastic modulus of compressed seawater and sea sand concrete, the method comprising: obtaining the designed compressive strength of the first concrete; wherein the first concrete is compressed seawater and sea sand concrete; based on a pre-constructed fitting strength model, obtaining the initial compressive strength of the second concrete and the initial compressive stress of the first concrete according to the designed compressive strength; wherein the second concrete is normally poured seawater and sea sand concrete; obtaining the actual compressive strength of the first concrete according to the initial compressive strength and the initial compressive stress; obtaining the target compressive strength of the second concrete and the target compressive stress of the first concrete according to the actual compressive strength and the designed compressive strength. The present application improves the compressive strength, elastic modulus and durability of seawater and sea sand concrete.

Description

Technical Field

[0001] The present application relates to the technical field of concrete strength design, and in particular to a strength and elastic modulus design method for compression-cast seawater and sea sand concrete. Background Art

[0002] The technical background of seawater and sea sand concrete stems from the shortage of freshwater and river sand resources and environmental protection needs. Due to the over-exploitation of river sand leading to resource depletion and environmental damage, seawater and sea sand have attracted attention as alternative materials. Marine resources are abundant, especially in coastal areas, and the use of seawater and sea sand can reduce costs. Technical research shows that through proper proportioning and treatment, seawater and sea sand concrete can achieve the strength and durability of traditional concrete. The research also explored anti-corrosion methods to reduce the impact of chloride ions on concrete. Some regions have begun to formulate relevant policies and standards to promote the application of this new material. Overall, the development of seawater and sea sand concrete technology is based on the rational use of resources, environmental protection needs, technological progress and policy promotion, and is expected to be widely used in the future, especially in coastal and island areas.

[0003] The existing technologies that can improve the performance of seawater and sea sand concrete mainly include the following: First, adding preservatives: adding preservatives (such as silane, siloxane or other chemical barriers) to concrete can reduce chloride ion penetration and improve the corrosion resistance of concrete; but the addition of preservatives requires precise control of dosage and uniform mixing, otherwise it may affect other properties of concrete. In addition, the cost and long-term effect of preservatives need further study. Second, using mineral admixtures: adding mineral admixtures such as fly ash, silica fume, slag powder, etc. can improve the microstructure of concrete, increase density and impermeability, and thus improve durability; but the quality and source of mineral admixtures need to be strictly controlled, otherwise it may lead to unstable concrete performance. In addition, the use of admixtures may affect the initial strength development of concrete. Third, desalination of sea sand: desalination of sea sand to remove salt can significantly reduce the content of chloride ions and reduce the risk of corrosion; but the desalination process is complicated and consumes a lot of water, which increases construction costs and time. In addition, the quality of treated sea sand needs to be strictly controlled. The above-mentioned prior art methods for improving concrete properties have poor effects on improving concrete properties.

[0004] Therefore, the prior art still needs to be improved and developed. Summary of the invention

[0005] The main purpose of this application is to provide a strength and elastic modulus design method for compression-cast seawater sand concrete, aiming to further provide technical support for the newly proposed compression casting technology, that is, given any design value of compression-cast seawater sand concrete, relevant parameters can be obtained to meet its design requirements. The problem that the existing technology of improving the performance of seawater sand concrete by adding preservatives, using mineral admixtures and desalination treatment of sea sand is poor in improving the performance of concrete is solved.

[0006] A first aspect of the present application provides a strength and elastic modulus design method for compression-cast seawater and sea sand concrete, comprising the following steps: obtaining a design compressive strength of a first concrete; wherein the first concrete is compression-cast seawater and sea sand concrete; based on a pre-constructed fitting strength model, obtaining an initial compressive strength of a second concrete and an initial compressive stress of the first concrete according to the design compressive strength; wherein the second concrete is normally cast seawater and sea sand concrete; obtaining an actual compressive strength of the first concrete according to the initial compressive strength and the initial compressive stress; and obtaining a target compressive strength of the second concrete and a target compressive stress of the first concrete according to the actual compressive strength and the design compressive strength.

[0007] Optionally, in one embodiment of the present application, the pre-constructed fitting strength model is based on which the initial compressive strength of the second concrete and the initial compressive stress of the first concrete are obtained according to the designed compressive strength, and the process also includes: obtaining a plurality of design values ​​of concrete strengths, and obtaining a plurality of corresponding actual values ​​according to the plurality of design values; obtaining concrete parameters according to the plurality of design values ​​and the plurality of actual values; and constructing a fitting strength model according to the concrete parameters.

[0008] Optionally, in one embodiment of the present application, the obtaining of the initial compressive strength of the second concrete and the initial compressive stress of the first concrete according to the designed compressive strength based on the pre-constructed fitting strength model specifically includes: obtaining a first strength range of the second concrete and a first compressive stress range of the first concrete according to the designed compressive strength based on the pre-constructed fitting strength model; determining the initial compressive strength from the first strength range, and calculating the corresponding initial compressive stress according to the initial compressive strength; wherein the initial compressive stress is within the first compressive stress range.

[0009] Optionally, in one embodiment of the present application, determining the initial compressive strength from the first strength range and calculating the corresponding initial compressive stress according to the initial compressive strength specifically include: obtaining a design elastic modulus of the first concrete, and based on the fitted strength model, obtaining a second strength range of the second concrete and a second compressive stress range of the first concrete according to the design elastic modulus; determining a target strength range of the second concrete according to the first strength range and the second strength range, and determining a target compressive stress range of the second concrete according to the first compressive stress range and the second compressive stress range; wherein the target compressive stress range is less than or equal to the first compressive stress range; determining the initial compressive strength from the target strength range; and calculating the corresponding initial compressive stress according to the initial compressive strength; wherein the initial compressive stress is within the target compressive stress range.

[0010] Optionally, in one embodiment of the present application, the fitting strength model is expressed as:

[0011]

[0012] Among them, f cc Expressed as the compressive strength of the first concrete, f co Expressed as the compressive strength of the second concrete, f p It is expressed as the compressive casting stress of the first concrete;

[0013]

[0014] E0=7000f co 0.31 ;

[0015] Wherein, E represents the elastic modulus of the first concrete, and E0 represents the elastic modulus of the second concrete.

[0016] Optionally, in an embodiment of the present application, obtaining the actual compressive strength of the first concrete according to the initial compressive strength and the initial compressive stress specifically includes: obtaining design parameters of the second concrete according to the initial compressive strength of the second concrete; performing concrete compression pouring according to the design parameters and the initial compressive stress to obtain the first concrete; and testing the first concrete to obtain the actual compressive strength of the first concrete.

[0017] Optionally, in one embodiment of the present application, the corresponding initial compressive stress is calculated according to the initial compressive strength, and then the step of: testing the first concrete to obtain an actual elastic modulus of the first concrete; if the actual elastic modulus is greater than the design elastic modulus, continuing to execute the step of obtaining a target compressive strength of the second concrete and a target compressive stress of the first concrete according to the actual compressive strength and the design compressive strength, until the actual elastic modulus is equal to the design elastic modulus.

[0018] Optionally, in one embodiment of the present application, obtaining the target compressive strength of the second concrete and the target compressive stress of the first concrete according to the actual compressive strength and the designed compressive strength specifically includes: calculating the difference between the actual compressive strength and the designed compressive strength; when the difference is within a preset range, taking the initial compressive strength as the target compressive strength, and taking the initial compressive stress as the target compressive stress; when the difference is outside the preset range, if the actual compressive strength is greater than the designed compressive strength, reducing the initial compressive stress to a target lowered compressive stress, taking the initial compressive strength as the target compressive strength, and taking the target lowered compressive stress as the target compressive stress; if the actual compressive strength is less than the designed compressive strength, increasing the initial compressive stress to a target higher compressive stress, taking the initial compressive strength as the target compressive strength, and taking the target higher compressive stress as the target compressive stress.

[0019] Optionally, in one embodiment of the present application, if the actual compressive strength is less than the designed compressive strength, the initial compressive stress is increased to a target increased compressive stress, and then the method further includes: if the target increased compressive stress is not within the target compressive stress range, the initial compressive strength is increased to an intermediate compressive strength; the corresponding intermediate compressive stress is calculated according to the intermediate compressive strength, and the intermediate actual compressive strength of the first concrete is obtained according to the intermediate compressive strength and the intermediate compressive stress, until the intermediate actual compressive strength, the intermediate compressive stress and the intermediate compressive strength meet the preset requirements, then the intermediate compressive strength is used as the target compressive strength, and the intermediate compressive stress is used as the target compressive stress.

[0020] Optionally, in one embodiment of the present application, the target compressive strength of the second concrete and the target compressive stress of the first concrete are obtained according to the actual compressive strength and the designed compressive strength, and then the method further includes: obtaining actual parameters of seawater and sea sand concrete according to the target compressive strength; and performing concrete compression pouring according to the actual parameters and the target compressive stress to obtain the first concrete.

[0021] Beneficial effects of this application:

[0022] The present application provides a strength and elastic modulus design method for compressed cast seawater sand concrete. The embodiment of the present application performs strength design and optimization based on a fitting strength model by giving a design value of the strength of the compressed cast seawater sand concrete, thereby obtaining the corresponding strength of the conventionally cast seawater sand concrete and the required compression casting stress, thereby improving the compressive strength and durability of the seawater sand concrete, avoiding re-testing and reducing costs.

[0023] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0025] Figure 1 It is a flow chart of a preferred embodiment of the strength and elastic modulus design method of the compressed seawater and sea sand concrete of the present application;

[0026] Figure 2 is a graph showing the relationship between the compression cast concrete strength and the compression cast stress in an embodiment of the present application;

[0027] Figure 3 is a strength model fitting curve diagram in the embodiment of the present application;

[0028] Figure 4 This is a strength model diagram of compressed seawater and sea sand concrete in an embodiment of the present application;

[0029] Figure 5 is a diagram of parameter value ranges in the embodiments of the present application;

[0030] Figure 6 This is a strength model diagram of compressed cast ordinary aggregate seawater and sea sand concrete in an embodiment of the present application;

[0031] Figure 7 This is a flow chart of strength design and optimization of compressed seawater and sea sand concrete in an embodiment of the present application;

[0032] Figure 8 This is a model diagram of elastic modulus of compression cast common aggregate seawater and sea sand concrete in an embodiment of the present application;

[0033] Fig. 9is an elastic modulus model evaluation diagram in an embodiment of the present application;

[0034] Fig.10 It is a model diagram of elastic modulus of compressed seawater and sea sand concrete in an embodiment of the present application;

[0035] Fig.11 It is a schematic diagram of the structure of the compression casting device and the sensor used in the manufacturing method in the embodiment of the present application. DETAILED DESCRIPTION

[0036] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0037] The following describes the strength and elastic modulus design method of the compressed cast seawater and sea sand concrete of the embodiment of the present application with reference to the accompanying drawings. In view of the problem that the method of improving the performance of seawater and sea sand concrete by adding preservatives, using mineral admixtures and desalination of sea sand in the related art mentioned in the above background technology has a poor effect on improving the performance of concrete, the present application provides a strength and elastic modulus design method of compressed cast seawater and sea sand concrete. In this method, by giving the design value of the strength of the compressed cast seawater and sea sand concrete, the strength design and optimization are performed based on the fitting strength model to obtain the corresponding strength of the ordinary cast seawater and sea sand concrete and the required compression casting stress, thereby improving the compressive strength and durability of the seawater and sea sand concrete, and avoiding re-testing and reducing costs. As a result, the technical problem that the method of improving the performance of seawater and sea sand concrete by adding preservatives, using mineral admixtures and desalination of sea sand in the related art has a poor effect on improving the performance of concrete is solved.

[0038] Based on the existing seawater and sea sand concrete, the embodiment of the present application further proposes a modified method of compression casting and a design method for determining its strength, and has the following advantages compared with the prior art:

[0039] (1) Improving concrete performance: By applying appropriate pre-stress to fresh seawater-sand concrete, its compressive strength and elastic modulus can be significantly improved, while its impermeability can also be improved, thereby enhancing its overall durability.

[0040] (2) Solve the problem of resource shortage: Compression casting technology does not require the addition of additional materials or special treatment of raw materials. It can make full use of abundant natural resources such as seawater and sea sand, effectively solving the problem of shortage of fresh water and river sand.

[0041] (3) Reduce costs and environmental impact: Since compression casting can increase the strength of concrete, it can reduce the amount of cement required under the same strength requirements, thereby reducing construction costs. It can also reduce environmental pollution emissions during the cement production process.

[0042] (4) Simple construction process: The operation of compression casting technology is relatively simple, and does not require complicated raw material pretreatment or admixture process, so it can be more conveniently applied on site.

[0043] In the embodiments of the present application, a physical modification method (compression casting) for seawater and sea sand concrete is adopted, and a modified compressive strength model is obtained through a batch of experiments. The model is used for strength design and optimization. For the design value of the strength of any given compression casting seawater and sea sand concrete, the corresponding parameters can be calculated, thereby avoiding re-testing, greatly reducing the time cost, economic cost and environmental cost. The embodiments of the present application can improve the compressive strength and durability of seawater and sea sand concrete, fit the compressive strength model through experiments, and give the strength design method of the modified concrete, as well as the strength correction method, which has guiding significance for the subsequent research on compression casting seawater and sea sand concrete. The strength and elastic modulus design method of the compression casting seawater and sea sand concrete of this embodiment is applied to all seawater and sea sand concrete, that is, it is applicable to different types of aggregates. The embodiments of the present application are illustrated by taking ordinary aggregate seawater and sea sand concrete as an example.

[0044] Specifically, Figure 1 A schematic flow chart of a method for designing the strength and elastic modulus of compressed seawater and sea sand concrete provided in an embodiment of the present application.

[0045] like Figure 4 As shown, the strength and elastic modulus design method of the compressed cast seawater and sea sand concrete includes the following steps:

[0046] In step S101, the designed compressive strength of the first concrete is obtained; wherein the first concrete is compressed and cast seawater and sea sand concrete.

[0047] It should be noted that the designed compressive strength is the compressive strength given by the compression-cast seawater and sea sand concrete (first concrete), and the compressive strength of the ordinary cast (i.e., non-compressed cast) seawater and sea sand concrete (i.e., second concrete) and the compressive casting stress of the second concrete raw material for compression casting are obtained by using the designed compressive strength. The first concrete is prepared using the raw materials and compressive casting stress of the second concrete compressive strength, so that the concrete performance of the obtained compression-cast seawater and sea sand concrete can be improved.

[0048] Specifically, determine the test plan. Figure 2 As shown in the experiment, it is known that the factors affecting the strength of compressed concrete (fcc ) has two main parameters, namely the compressive strength of normal poured concrete (f co ) and compressive casting stress (f p ), further analysis shows that f p With f co Linearly related, because f co It is related to the type of aggregate. The higher the strength of the aggregate, the more f it can withstand. p The higher the value, the higher the value. And according to experiments, for different f co The same f is applied to the concrete p , f of concrete with low initial strength cc The improvement is large, and the relationship between the three is as follows Figure 2 As shown, where k is the slope.

[0049] With f co As a variable, the gradient design is carried out according to the strength. Under the condition of the same aggregate, the water-binder ratio can be adjusted to control f co The smaller the water-binder ratio, the greater the f co The larger the value, the greater the value. Then at each same f co Under different conditions, different pressures are applied to produce different f p , f p The value should be selected according to the gradient within the value range. p The value range should be the rising section of the curve, that is, 0-f pn (n=1,2,3,……), f pn for Figure 2 The f corresponding to the peak points of different curves p value, because appropriate compressive casting stress can improve the compressive strength of concrete, but continuing to increase the compressive casting stress after the peak point will cause the crushing of aggregates, resulting in cracks in the specimens and reducing the durability of the structure, which is a great hazard to seawater and sea sand concrete.

[0050] f pn The method for determining f is experimental method. Since three-dimensional compression will increase the compressive strength of aggregate, f pn It should be slightly greater than the compressive strength of the aggregate, so that the concrete can be given a slightly greater value than f in the compression pouring device. co The pressure is then applied, and then the concrete is immediately poured out to observe the state of the aggregate. If the aggregate is intact, it is poured back into the device, and a greater stress is applied, and then the concrete is poured out for observation until the concrete aggregate is crushed in small amounts. The stress in this state is f pn .

[0051] In a possible implementation, a plurality of design values ​​of concrete strength are obtained, and a plurality of corresponding actual values ​​are obtained according to the plurality of design values; concrete parameters are obtained according to the plurality of design values ​​and the plurality of actual values; and a fitting strength model is constructed according to the concrete parameters.

[0052] Specifically, the design specimen parameters (i.e. concrete parameters) are determined. Based on the above principles, taking ordinary aggregate seawater and sea sand concrete as an example, an experimental scheme is designed to take three f according to the gradient. co The design values ​​are 20, 30 and 40 MPa respectively, and the actual values ​​measured in the experiment are 22.35, 30.53 and 39.36 MPa. Concrete is mixed with these three concrete mix proportions at 0-f pn The specific specimen parameters are shown in Table 1.

[0053] Table 1: Specimen parameters

[0054]

[0055] It should be noted that SS is sea sand, SW is sea water, S10P is the compressive casting stress of 10 MPa, NP is no pressure applied, and f p is the compressive casting stress, f co orf cc is the compressive strength of concrete poured normally or compressed, T is the compression time, E is the elastic modulus, w is the weight of water, and c is the weight of cement.

[0056] Specifically, a fitting strength model is obtained according to the experimental results.

[0057] Taking the compression casting of seawater and sea sand concrete with ordinary aggregate as an example, a batch of seawater and sea sand concrete specimens were made (Table 1). The data are shown in the table, and their compressive strengths were measured respectively. The fitting strength models are shown in equations (1) and (2).

[0058]

[0059] Where: f co = compressive strength of normal poured concrete (measured experimentally);

[0060] f cc = compressive strength of cast-in-place concrete (measured experimentally);

[0061] f p =Compressive casting stress.

[0062]

[0063] Among them: F p = compression pouring pressure;

[0064] S = cross-sectional area of ​​the concrete specimen.

[0065] The fitting effect is as follows Figure 3 As shown in the figure, R 2 =0.996, so the model is reliable and can be used for strength design of seawater sand concrete. Therefore, the strength design of any compressed seawater sand concrete can be carried out. The strength model of compressed seawater sand concrete is as follows: Figure 4 As shown. Among them, f cc0 is the strength of the uncompressed poured concrete. The area above this surface is the strength improvement area, and its formula is formula (4).

[0066]

[0067] Among them, a and b are constants, and the values ​​of a and b are different for concrete with different aggregates.

[0068] In step S102, based on the pre-constructed fitting strength model, the initial compressive strength of the second concrete and the initial compressive stress of the first concrete are obtained according to the designed compressive strength; wherein the second concrete is normally cast seawater and sea sand concrete.

[0069] In a possible implementation, based on a pre-constructed fitting strength model, a first strength range of the second concrete and a first compressive stress range of the first concrete are obtained according to the designed compressive strength; an initial compressive strength is determined from the first strength range, and a corresponding initial compressive stress is calculated according to the initial compressive strength; wherein the initial compressive stress is within the first compressive stress range.

[0070] Specifically, the strength design is carried out according to the strength model. The strength design goal of compressed seawater sand concrete is to cc (can be achieved), we can get the appropriate f co The range and corresponding f p That is, given any given strength of compressed seawater sand concrete, the appropriate strength of uncompressed seawater sand concrete and the corresponding compressed casting stress can be obtained. Figure 4 As shown, if the given f cc The value of f ccd , then the surface and f ccd The intersection points of the corresponding planes are all possible f co and its corresponding f p A collection of .

[0071] Take the compression casting of seawater sand concrete with ordinary aggregate as an example. Figure 5As shown in Figure 2, corresponding to formula (2), the parameter value range should be the blue area, that is, the strength improvement area, because appropriate compressive casting stress can improve the compressive strength of concrete, but continuing to increase the compressive casting stress after the peak point will cause the crushing of aggregates, resulting in cracks in the specimen and reducing the durability of the structure, which is a great hazard to seawater sand concrete. Therefore, f p / f co The value range is 0-0.729, f cc / f co The value range is 1-1.745.

[0072] Further, an example is given: for a compressed seawater sand concrete with a design strength of 50 MPa, the first step is to calculate the strength of the uncompressed seawater sand concrete (f co ) has a value range of 28.65-50 (50 / 1.745–50) MPa. co (You can also take f in Table 1 co ), such as 30 and 40 MPa. The second step is to calculate the corresponding compressive casting stress f p According to formula 1, we can calculate f p / f co They are 0.492 and 0.135 respectively, which meet the requirements of the value range. Then calculate f p 14.76 and 5.4MPa respectively, and the design is completed. Through the strength model analysis method, such as Figure 6 shown.

[0073] In step S103, the actual compressive strength of the first concrete is obtained according to the initial compressive strength and the initial compressive stress.

[0074] In a possible implementation, design parameters of the second concrete are obtained according to the initial compressive strength of the second concrete; concrete compression pouring is performed according to the design parameters and the initial compressive stress to obtain the first concrete; and the first concrete is tested to obtain actual compressive strength and actual elastic modulus of the first concrete.

[0075] Specifically, the raw materials and parameters of each raw material (i.e., design parameters) are determined for ordinary cast seawater and sea sand concrete (second concrete), and then the first concrete is obtained according to the design parameters and the initial compressive stress (corresponding to the preparation of the first concrete), and then the first concrete is tested to obtain the actual compressive strength.

[0076] In step S104, the target compressive strength of the second concrete and the target compressive stress of the first concrete are obtained according to the actual compressive strength and the designed compressive strength.

[0077] In a possible implementation, the difference between the actual compressive strength and the designed compressive strength is calculated; when the difference is within a preset range, the initial compressive strength is used as the target compressive strength, and the initial compressive stress is used as the target compressive stress; when the difference is outside the preset range, if the actual compressive strength is greater than the designed compressive strength, the initial compressive stress is reduced to a target lowered compressive stress, the initial compressive strength is used as the target compressive strength, and the target lowered compressive stress is used as the target compressive stress; if the actual compressive strength is less than the designed compressive strength, the initial compressive stress is increased to a target higher compressive stress, the initial compressive strength is used as the target compressive strength, and the target higher compressive stress is used as the target compressive stress.

[0078] In a possible implementation, if the target increased compressive stress is not within the target compressive stress range, the initial compressive strength is increased to the intermediate compressive strength; the corresponding intermediate compressive stress is calculated according to the intermediate compressive strength, and the intermediate actual compressive strength of the first concrete is obtained according to the intermediate compressive strength and the intermediate compressive stress, until the intermediate actual compressive strength, the intermediate compressive stress and the intermediate compressive strength meet the preset requirements, then the intermediate compressive strength is used as the target compressive strength, and the intermediate compressive stress is used as the target compressive stress.

[0079] Specifically, optimization and adjustment. The actual value of the compressive strength of the seawater sand concrete designed according to the model will have a small error with the design value. If it is within the allowable error range, no adjustment is required. If it exceeds the allowable error range, fine-tuning is required. Specifically, it can be divided into the following two situations. If f cc The actual value (f cce ) is greater than f cc The design value (f ccd ), then appropriately reduce f p If f cc The actual value (f cce ) is less than f cc The design value (f ccd ), then appropriately increase f p , and then determine f p Is it within the value range, such as f p If the maximum value cannot meet the requirement, then a larger f co Recalculate again. Design and optimization process, see Figure 7 .

[0080] In a possible implementation, a design elastic modulus of the first concrete is obtained, and based on the fitted strength model, a second strength range of the second concrete and a second compressive stress range of the first concrete are obtained according to the design elastic modulus; a target strength range of the second concrete is determined according to the first strength range and the second strength range, and a target compressive stress range of the second concrete is determined according to the first compressive stress range and the second compressive stress range; wherein the target compressive stress range is less than or equal to the first compressive stress range; an initial compressive strength is determined from within the target strength range; and a corresponding initial compressive stress is calculated according to the initial compressive strength; wherein the initial compressive stress is within the target compressive stress range.

[0081] It should be noted that the specific implementation steps of the embodiment of the present application are: first determine the design compressive strength of the compressed seawater and sea sand concrete, obtain a first strength range (i.e., an initial compressive strength range) and a first compressive stress range (i.e., an initial pressure range) based on the design compressive strength, and then further narrow the range by determining the design elastic modulus, and then determine the design target compressive strength (i.e., the initial compressive strength) from the narrowed target range, and calculate the target design compression pressure (i.e., the initial compression stress) based on the design target compressive strength.

[0082] Specifically, the elastic modulus of compressed seawater sand concrete is verified. Under the action of appropriate compression casting stress, the concrete is compressed in three directions due to the pressure, the interface transition zone will become smaller and the material stacking will be more compact, so the elastic modulus will increase, but greater pressure will cause the aggregate to be crushed, resulting in a decrease in the elastic modulus. A too small elastic modulus will cause excessive deformation of the concrete structure, affecting the overall stability and use function of the structure. It may also cause excessive deflection in some bending members, affecting the performance. It will also make the member's crack resistance poor and prone to cracking during use. The most important thing is that it will lead to poor durability and easy to have quality problems in long-term use, which should be absolutely avoided in seawater sand concrete.

[0083] First, taking ordinary aggregate seawater sand concrete as an example, the elastic modulus (E) of compressed seawater sand concrete was fitted through the data of the specimen (see Table 1). The model is shown in formula (5), and the three-dimensional graph is shown in Figure 8 shown.

[0084]

[0085] Where: E is the elastic modulus of compressed seawater sand concrete;

[0086] E0 is the elastic modulus of uncompressed seawater sand concrete.

[0087] The proposed model of elastic modulus is evaluated, e.g. Fig. 9 It can be seen that the data points are distributed near the straight line, that is, the predicted value of the elastic modulus is close to the experimental value, and the fitting effect is good.

[0088] Therefore, the elastic modulus model of compressed seawater sand concrete with any aggregate can be obtained, as shown in Equation 6, and the three-dimensional graph is as follows: Fig.10 shown.

[0089]

[0090] Among them, the surface is E and the black curve is E0.

[0091] In a possible implementation, the first concrete is tested to obtain an actual elastic modulus of the first concrete; if the actual elastic modulus is greater than the designed elastic modulus, the step of obtaining a target compressive strength of the second concrete and a target compressive stress of the first concrete according to the actual compressive strength and the designed compressive strength is continued.

[0092] Specifically, the arbitrary compression casting seawater sand concrete f co and f p The value range of E can be substituted into the formula of E to calculate the value of E. If E ≥ E0, it is acceptable. If E < E0, it is not acceptable (that is, only the f corresponding to the part of the E surface above the E0 curve can be taken). co and fp). For example, Fig.10 As shown, in f co Choose any f in the range co1 , the corresponding elastic modulus is E1, f p The range of the value of is the range corresponding to the part of the E surface above the E1 plane. Thus, f is further limited co The range of fp and fp is such that the elastic modulus requirement is met, making the strength and elastic modulus design method of the compressed seawater and sea sand concrete more reliable.

[0093] In a possible implementation, actual parameters of seawater and sea sand concrete are obtained according to the target compressive strength; and concrete compression pouring is performed according to the actual parameters and the target compressive stress to obtain the first concrete (i.e., compression poured seawater and sea sand concrete).

[0094] For details, see Fig.11 The method for making compressed seawater and sea sand concrete comprises the following steps:

[0095] ①Concrete mixing

[0096] First, prepare the various raw materials of concrete, including cement, sea sand, gravel and sea water, and weigh them according to the specified mix ratio. Pour these raw materials into the mixer and start the mixer to mix them, ensuring that all ingredients are evenly mixed until the concrete reaches the required uniformity and consistency. The mixing time is generally 3-5 minutes, and the specific time is adjusted according to the materials and environmental conditions.

[0097] ②Filling steel mold

[0098] Pour the freshly mixed concrete into the prepared compression pouring device (see Figure 1 ) in the steel mold. The steel mold should be clean and free of oil, and should be coated with a release agent in advance to facilitate subsequent demoulding. Make sure that the concrete fills the steel mold without leaving any gaps.

[0099] ③Vibration

[0100] Use a vibrating rod to vibrate the concrete filled in the steel mold. When vibrating, the vibrating rod should be inserted vertically into the concrete to a depth that reaches the bottom of the concrete, and gradually lifted and moved to avoid vibrating at the same position for too long to eliminate bubbles and voids in the concrete and ensure the density of the concrete. Each vibration time should not be too long, generally between 15-30 seconds.

[0101] ④ Mechanical sensor installation

[0102] Install a mechanical sensor under the steel mold. The mechanical sensor should be placed on the pressure-bearing surface of the steel mold to monitor and record the applied pressure in real time. The digital indicator should be connected to the mechanical sensor and display real-time data during the pressure application process to ensure accurate control of the pressure application process. The working status of the sensor and indicator should be checked before installation to ensure the normal operation of the equipment.

[0103] ⑤Pressure application

[0104] Use a hydraulic jack to apply axial pressure to the fresh concrete. Apply pressure slowly and evenly to avoid sudden force that may damage the internal structure of the concrete. Monitor the applied pressure in real time through a digital indicator and gradually increase the pressure to the predetermined rated value. Stop applying pressure after reaching the rated pressure. Keep the hydraulic jack stable during the pressure application process to prevent bias and tilt.

[0105] ⑥Pressure maintenance

[0106] When the pressure reaches the rated value, maintain the pressure for 10 minutes to ensure that the internal structure of the concrete is fully compacted under pressure. During this period, the pressure should be checked and adjusted regularly to ensure that the pressure value remains constant. When maintaining the pressure, vibration and impact should be avoided to avoid affecting the compaction effect of the concrete.

[0107] ⑦ Unloading and demoulding

[0108] After the pressure is maintained for 10 minutes, slowly unload the pressure to avoid sudden pressure release and damage to the concrete sample. After the pressure is released, carefully remove the sample from the steel mold to ensure that the surface of the sample is smooth and without defects. When demolding, avoid the sample from being affected by external forces to prevent damage.

[0109] ⑧Maintenance

[0110] After demoulding, the concrete specimens should be immediately placed in a standard curing environment for curing. The curing conditions should meet the requirements of relevant standards, generally including temperature (20±2℃), relative humidity (above 95%), etc. The curing time is 28 days to ensure that the concrete specimens achieve the required strength and performance during the curing period.

[0111] The embodiment of the present application also provides a strength design device for compressing and pouring seawater and sea sand concrete. The strength design device for compressing and pouring seawater and sea sand concrete may include: a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the strength and elastic modulus design method for compressing and pouring seawater and sea sand concrete provided in the above embodiment is implemented.

[0112] This embodiment also provides a computer-readable storage medium, on which a computer program is stored. When the program is executed by a processor, the above-mentioned method for correcting the heading angle inversion is implemented.

[0113] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or N embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0114] In addition, the terms "first" and "second" are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "N" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. Any process or method description in the flowchart or otherwise described herein may be understood to represent a module, fragment or portion of a code including one or N executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes additional implementations, in which the functions may not be performed in the order shown or discussed, including in a substantially simultaneous manner or in a reverse order according to the functions involved, which should be understood by a technician in the technical field to which the embodiments of the present application belong.

[0115] It should be understood that the application of the present application is not limited to the above examples. For ordinary technicians in this field, improvements or changes can be made based on the above description. All these improvements and changes should fall within the scope of protection of the claims attached to this application.

Claims

1. A method for designing the strength and elastic modulus of compressed seawater and sea sand concrete, characterized in that: The strength and elastic modulus design method of the compressed seawater and sea sand concrete comprises: Obtaining the designed compressive strength of the first concrete; wherein the first concrete is compressed and cast seawater and sea sand concrete; Based on the pre-constructed fitting strength model, the initial compressive strength of the second concrete and the initial compressive stress of the first concrete are obtained according to the designed compressive strength; wherein the second concrete is a normally poured seawater and sea sand concrete; Obtaining the actual compressive strength of the first concrete according to the initial compressive strength and the initial compressive stress; According to the actual compressive strength and the designed compressive strength, obtaining a target compressive strength of the second concrete and a target compressive stress of the first concrete; The obtaining of the initial compressive strength of the second concrete and the initial compressive stress of the first concrete based on the pre-constructed fitting strength model and the designed compressive strength specifically includes: Based on a pre-constructed fitting strength model, obtaining a first strength range of the second concrete and a first compressive stress range of the first concrete according to the designed compressive strength; Determine an initial compressive strength from the first strength range, and calculate a corresponding initial compressive stress according to the initial compressive strength; wherein the initial compressive stress is within the first compressive stress range; The fitted strength model is expressed as: ； ； in, Expressed as the compressive strength of the first concrete, Expressed as the compressive strength of the second concrete, It is expressed as the compressive casting stress of the first concrete; ； ； in, Expressed as the elastic modulus of the first concrete, Expressed as the elastic modulus of the second concrete.

2. The strength and elastic modulus design method for compression casting of seawater and sea sand concrete according to claim 1 is characterized in that: The method of obtaining the initial compressive strength of the second concrete and the initial compressive stress of the first concrete based on the pre-built fitting strength model according to the designed compressive strength also includes: Acquire multiple design values ​​of concrete strength, and obtain corresponding multiple actual values ​​according to the multiple design values; Obtaining concrete parameters according to the plurality of design values ​​and the plurality of actual values; A fitting strength model is constructed according to the concrete parameters.

3. The strength and elastic modulus design method for compression casting of seawater and sea sand concrete according to claim 1 is characterized in that: Determining the initial compressive strength from the first strength range, and calculating the corresponding initial compressive stress according to the initial compressive strength, specifically includes: Acquire a design elastic modulus of the first concrete, and acquire a second strength range of the second concrete and a second compressive stress range of the first concrete according to the design elastic modulus based on the fitted strength model; Determining a target strength range of the second concrete according to the first strength range and the second strength range, and determining a target compressive stress range of the second concrete according to the first compressive stress range and the second compressive stress range; wherein the target compressive stress range is less than or equal to the first compressive stress range; determining an initial compressive strength from within the target strength range; The corresponding initial compressive stress is calculated according to the initial compressive strength; wherein the initial compressive stress is within the target compressive stress range.

4. The strength and elastic modulus design method for compression casting of seawater and sea sand concrete according to claim 3 is characterized in that: The obtaining, according to the initial compressive strength and the initial compressive stress, an actual compressive strength of the first concrete specifically includes: acquiring design parameters of the second concrete according to the initial compressive strength of the second concrete; Performing concrete compression pouring according to the design parameters and the initial compressive stress to obtain the first concrete; The first concrete is tested to obtain the actual compressive strength of the first concrete.

5. The strength and elastic modulus design method for compression casting of seawater and sea sand concrete according to claim 4, characterized in that: The step of calculating the corresponding initial compressive stress according to the initial compressive strength further comprises: Testing the first concrete to obtain an actual elastic modulus of the first concrete; If the actual elastic modulus is greater than the designed elastic modulus, the step of obtaining the target compressive strength of the second concrete and the target compressive stress of the first concrete according to the actual compressive strength and the designed compressive strength is continued until the actual elastic modulus is equal to the designed elastic modulus.

6. The strength and elastic modulus design method for compression casting of seawater and sea sand concrete according to claim 4, characterized in that: The obtaining, according to the actual compressive strength and the designed compressive strength, a target compressive strength of the second concrete and a target compressive stress of the first concrete specifically includes: Calculating the difference between the actual compressive strength and the designed compressive strength; When the difference is within a preset range, the initial compressive strength is used as the target compressive strength, and the initial compressive stress is used as the target compressive stress; When the difference is outside the preset range, if the actual compressive strength is greater than the design compressive strength, the initial compressive stress is reduced to the target lowered compressive stress, the initial compressive strength is used as the target compressive strength, and the target lowered compressive stress is used as the target compressive stress; if the actual compressive strength is less than the design compressive strength, the initial compressive stress is increased to the target higher compressive stress, the initial compressive strength is used as the target compressive strength, and the target higher compressive stress is used as the target compressive stress.

7. The strength and elastic modulus design method for compression casting of seawater and sea sand concrete according to claim 6, characterized in that: If the actual compressive strength is less than the designed compressive strength, the initial compressive stress is increased to a target increased compressive stress, and then further comprising: If the target increased compressive stress is not within the target compressive stress range, increasing the initial compressive strength to an intermediate compressive strength; The corresponding intermediate compressive stress is calculated according to the intermediate compressive strength, and the intermediate actual compressive strength of the first concrete is obtained according to the intermediate compressive strength and the intermediate compressive stress, until the intermediate actual compressive strength, the intermediate compressive stress and the intermediate compressive strength meet the preset requirements, then the intermediate compressive strength is used as the target compressive strength, and the intermediate compressive stress is used as the target compressive stress.

8. The strength and elastic modulus design method for compression casting seawater and sea sand concrete according to any one of claims 1-2, characterized in that: The step of obtaining a target compressive strength of the second concrete and a target compressive stress of the first concrete according to the actual compressive strength and the designed compressive strength further comprises: According to the target compressive strength, actual parameters of seawater and sea sand concrete are obtained; Concrete compression pouring is performed according to the actual parameters and the target compressive stress to obtain the first concrete.

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