Information processing device, design support device, information processing method, and program

Abstract

The present invention provides an information processing device, a design support device, and an information processing method that support the design of concrete structures. [Solution] An information processing device 2 according to one aspect of the present disclosure includes an estimation unit 102 that estimates at least one of the strain distribution and stress distribution in a cross-section of a concrete structure whose volume change is constrained by a constraint body and which has a cross-section without an axis of symmetry, based on the age of the members used in the concrete structure and / or the amount of shrinkage over time due to the free strain of the concrete structure.

Description

[Technical Field]

[0001] This disclosure relates to an information processing device, a design support device, an information processing method, and a program. [Background technology]

[0002] Conventional techniques for analyzing stress distribution in concrete structures are known. For example, Patent Document 1 describes a design support device that can improve the accuracy of strain distribution and stress distribution analysis for any cross-sectional shape of a concrete structure. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Patent No. 7129218 Publication [Overview of the project] [Problems that the invention aims to solve]

[0004] However, the technology described in Patent Document 1 does not fully support the design of concrete structures. For example, it does not fully support the design of concrete structures that take into account the shrinkage over time.

[0005] Therefore, this disclosure aims to provide an information processing device, a design support device, and an information processing method that support the design of concrete structures. [Means for solving the problem]

[0006] An information processing device according to one aspect of the present disclosure estimates at least one of the strain distribution and stress distribution in a cross-section of a concrete structure whose volume change is constrained by a constraint body and which has a cross-section without an axis of symmetry, based on the age of the members used in the concrete structure and / or the amount of shrinkage over time due to the free strain of the concrete structure.

[0007] Another aspect of the present disclosure is a design support device for designing a concrete structure having a cross section in which volume change is constrained by a restraining body and which has no axis of symmetry, comprising an estimation unit that estimates at least one of the strain distribution and stress distribution in the cross section of the concrete structure based on the age of the members used in the concrete structure and / or the amount of shrinkage over time due to free strain of the concrete structure.

[0008] An information processing method according to another aspect of the present disclosure involves causing at least one processor to estimate at least one of the strain distribution and stress distribution in a cross-section of a concrete structure having a cross-section in which the volume change is constrained by a constraint and which has no axis of symmetry, based on the age of the members used in the concrete structure and / or the amount of shrinkage over time due to the free strain of the concrete structure.

[0009] A program according to another aspect of the present disclosure causes at least one processor to estimate at least one of the strain distribution and stress distribution in a cross-section of a concrete structure having a cross-section in which the volume change is constrained by a constraint and which has no axis of symmetry, based on the age of the members used in the concrete structure and / or the amount of shrinkage over time due to free strain of the concrete structure. [Effects of the Invention]

[0010] According to this disclosure, it is possible to provide an information processing device, a design support device, and an information processing method that support the design of concrete structures. [Brief explanation of the drawing]

[0011] [Figure 1] This diagram shows an example configuration of System 1. [Figure 2] This figure shows an example of the operation of the information processing device 2. [Figure 3] This figure shows an example of the operation of the information processing device 2. [Figure 4] This figure shows an example of the display screen of terminal device 3. [Figure 5] This figure shows an example of the display screen of terminal device 3. [Figure 6] This diagram shows an example of the hardware configuration of various devices included in System 1. [Figure 7] This figure shows an example of a conceptual diagram of an equilibrium condition model. [Figure 8] This figure shows an example of axial cross-sectional analysis. [Figure 9] This figure shows an example of axial cross-sectional analysis. [Figure 10] This figure shows an example of axial cross-sectional analysis. [Figure 11] This figure shows an example of free strain in concrete. [Figure 12A] This is a schematic diagram showing the shape and dimensions of the test specimen and the installation procedure. [Figure 12B] This is a schematic diagram showing the shape and dimensions of the test specimen and the installation procedure. [Figure 12C] This is a schematic diagram showing the shape and dimensions of the test specimen and the installation procedure. [Figure 13] This diagram shows the combination of experimental levels and concrete mix designs. [Figure 14] This figure shows the change in strain of reinforcing bars in the axial direction of the bridge over time. [Figure 15] This figure shows the change over time in the stress (calculated value) in the bridge axis direction. [Figure 16] This is an example of a contour plot showing the stress distribution (calculated value) in the bridge axis direction. [Figure 17] This figure shows the stress during the casting process of floor slabs and wall railings using the simplified method, and the prediction of crack occurrence during the shrinkage process. [Figure 18] This is a diagram showing the conversion of shrinkage strain to unit strain. [Figure 19] This figure shows the ratio of shrinkage strain to post-casting. [Figure 20] This figure shows a conceptual diagram of how crack formation is predicted. [Figure 21] This figure shows the effect of the shrinkage strain setting on stress behavior. [Figure 22] This is a diagram showing a list of input conditions for the analysis. [Figure 23] This figure shows the input conditions for the analysis. [Figure 24] This is a diagram showing the timetable. [Figure 25] This figure shows the application conditions and number of steps for the constitutive law. [Modes for carrying out the invention]

[0012] Preferred embodiments of this disclosure will be described with reference to the attached drawings. (Note that components denoted by the same reference numerals in each drawing have the same or similar configurations.)

[0013] Chemically Prestressed Concrete (CPC) members, which use expansive concrete in reinforced concrete (RC) members, introduce chemical prestress (compressive stress) and chemical pretrain (expansion strain) by constraining their volume change. The chemical prestress and chemical pretrain that occur in actual members can be easily estimated by applying the assumption of constant work rate from the results of a uniaxially restrained expansion test of expansive concrete of the same mix. This estimation method is limited to cases where there is at least one axis of symmetry within the cross-section of the CPC member, and is often applied by assuming a symmetrical cross-section with a vertical axis of symmetry using a layered model. Patent Document 1 describes an estimation method that expands the scope of application by using a layered model to include cases where expansive concrete is used in RC members where there is no axis of symmetry in the cross-sectional shape dimensions and reinforcement arrangement, such as wall parapets on the deck slab of a road bridge, and also to cross-sections without an axis of symmetry during the construction process, such as when wall parapets are cast one side at a time, even in symmetrical cross-sections.

[0014] One exemplary embodiment of this disclosure further extends the estimation method for CPC members without a symmetry axis, providing a method for estimating the stress distribution and strain distribution that occur in the cross-section over the long term, using volume changes such as drying shrinkage due to the subsequent aging as input values. A simple evaluation method for the crack suppression effect of applying expansive concrete is also provided.

[0015] <Example configuration of System 1> Referring to Figure 1, an example configuration of System 1 (hereinafter simply referred to as "System 1") according to this embodiment will be described. System 1 includes an information processing device 2, a terminal device 3, and a communication network 4.

[0016] [Information Processing Device 2] The information processing device 2 is a device that assists in the design of concrete structures. In one embodiment, the information processing device 2 assists in the design of concrete structures in which volume changes are constrained by a constraint body and which have a cross-section without an axis of symmetry. Hereinafter, concrete structures will be described as having volume changes constrained by a constraint body and which have a cross-section without an axis of symmetry.

[0017] In one embodiment, the information processing device 2 is a server device when the terminal device 3 is a client device. That is, the information processing device 2 can receive a request from the terminal device 3, perform a predetermined process in response to the request, and transmit the result to the terminal device 3.

[0018] The information processing device 2 comprises a control unit 10, a storage unit 12, a network interface unit 14, and a bus 16. The control unit 10, the storage unit 12, and the network interface unit 14 are electrically connected via the bus 16.

[0019] (Control Unit 10) The control unit 10 can function as an acquisition unit 100, an estimation unit 102, a determination unit 104, a decision unit 106, and an output unit 108 by executing various programs stored in the storage unit 12, which will be described later.

[0020] ≪Acquisition part 100≫ The acquisition unit 100 acquires information regarding the age of members used in concrete structures. The age of a member is the time elapsed since the member was constructed as part of a concrete structure, and can be, for example, "1 year," "3 years," and "10 years."

[0021] Furthermore, the acquisition unit 100 acquires information regarding the amount of shrinkage over time due to free strain in the concrete structure. The amount of shrinkage over time can be determined based on the ratio of the length of the concrete structure at an initial point in time to the length at a point after a predetermined period has elapsed. Note that drying shrinkage, which occurs when the concrete hardens and moisture evaporates, is one example of shrinkage over time.

[0022] In one embodiment, the acquisition unit 100 acquires information regarding the age of a material and / or the amount of shrinkage over time that has been input to the terminal device 3. In another embodiment, the acquisition unit 100 acquires information regarding the age of a material and / or the amount of shrinkage over time that has been previously stored in the storage unit 12. In yet another embodiment, the acquisition unit 100 acquires information regarding the age of a material and / or the amount of shrinkage over time from another server device.

[0023] In this disclosure, "acquiring information" includes making the information available for processing by the control unit 10. "Acquiring information" may include, for example, receiving the information from another device, reading the information from the storage unit 12, or generating the information as a result of a predetermined process.

[0024] ≪Estimation section 102≫ —Estimation of target distribution based on the age of the material— The estimation unit 102 estimates at least one of the strain distribution and stress distribution in a cross-section of a concrete structure that does not have an axis of symmetry. The estimation by the estimation unit 102 may be an estimation of the current strain distribution or stress distribution based on the current age or shrinkage of the member, or it may be an estimation of the future or hypothetical strain distribution or stress distribution based on the future or hypothetical age or shrinkage of the member.

[0025] Hereafter, when strain distribution and stress distribution are not specifically distinguished, or when they are referred to collectively, they will be referred to as "target distribution." Also, hereafter, the cross section that is the target of estimation of the target distribution will be referred to as the "target cross section." That is, the estimation unit 102 estimates the target distribution in the target cross section of the concrete structure.

[0026] In one embodiment, the estimation unit 102 estimates the target distribution in a target cross-section based on the age of the member used in the concrete structure. In this case, the estimation unit 102 may divide the age into arbitrary periods and estimate the target distribution at a predetermined age by adding up the increments of strain and / or stress that occur in the target cross-section during each period.

[0027] The estimation unit 102 can estimate the target distribution in the target cross-section based, for example, on the sum of (1) to (4) below. (1) The increase in strain and / or stress occurring in the cross-section in question during the period from the initial point to the first point in time. (2) The increase in strain and / or stress occurring in the cross-section in question during the period from the first time point to the second time point. (3) The increase in strain and / or stress occurring in the cross-section in question during the period from the second time point to the third time point. (4) The increase in strain and / or stress that occurs in the cross section in question during the period from the third point in time until the member reaches its age. Note that the above example describes dividing the period from the initial stage to the end of the material's lifespan into four parts, but the number of divisions can be arbitrary.

[0028] The Young's modulus of a concrete structure can change over time. Furthermore, the rate of shrinkage per unit time of a concrete structure can also change over time. Therefore, in order to estimate the target distribution in a target cross-section after a predetermined period from the initial point in time, it is necessary to consider the Young's modulus and the rate of shrinkage per unit time for each of the multiple periods from the initial point to that point in time. According to the above configuration, it is possible to estimate the target distribution while taking into account such changes in the state of the concrete structure over time.

[0029] Furthermore, the changes in Young's modulus and the amount of shrinkage per unit time become sufficiently small as time passes since the concrete was poured. In that case, the estimation unit 102 can estimate the target distribution by ignoring the changes in Young's modulus and the amount of shrinkage per unit time. That is, for the period after a sufficient amount of time has passed since the concrete was poured, the estimation unit 102 can estimate the target distribution by assuming that Young's modulus and the amount of shrinkage per unit time are constant.

[0030] Specifically, during the period in which such assumptions hold, the estimation unit 102 can estimate the target distribution of the target cross-section of the concrete structure at the age of the member acquired by the acquisition unit 100 by multiplying the amount of change per unit period of the target distribution in the target cross-section of the concrete structure by a predetermined coefficient. The predetermined coefficient may be the ratio of the length of the unit period to the length of the period related to the age of the member. The period related to the age of the member may be the period from a reference point after a sufficient period has elapsed since the concrete was poured (i.e., the period in which the above assumptions hold) until the member reaches its age.

[0031] For example, if there is a change in X in the target distribution of the target cross-section over 10 days from a reference point (an example of a unit period), and the member reaches its age 100 days after that reference point, the estimation unit 102 can estimate that the change in the target distribution from the reference point until the member reaches its age is 10X (= X, which is the amount of change per unit period × (100 days, which is the period until the member reaches its age / 10 days, which is the unit period)). Here, 10 to 100 days is considered to be the period during which at least the above assumption holds. Note that X may be a two-dimensional vector in which each element represents the stress at a certain coordinate.

[0032] This configuration reduces the computational complexity required to estimate the target distribution compared to the method described above, which divides the age of the material into arbitrary periods and sums up the increments of strain and / or stress in each divided period.

[0033] —Estimation of target distribution based on time-dependent contraction— Concrete structures shrink over time due to drying shrinkage and other factors. Therefore, if the age of a member is determined, the amount of shrinkage of the concrete structure at that age can be determined. Furthermore, if the amount of shrinkage of the concrete structure is determined, the age at which that amount of shrinkage occurs can be determined. Thus, the method for estimating the target distribution described above can also be performed by replacing the age of the member with the amount of shrinkage.

[0034] In one embodiment, the estimation unit 102 estimates the target distribution in the target cross section based on the amount of shrinkage over time due to the free strain of the concrete structure. In this case, the estimation unit 102 can estimate the target distribution in the target cross section during the period in which shrinkage of the first length + second length occurs, based on at least the increase in strain and / or stress that occurs in the target cross section during the period in which shrinkage of the first length occurs, and the increase in strain and / or stress that occurs in the target cross section during the period in which shrinkage of the second length occurs.

[0035] In one embodiment, the estimation unit 102 estimates the target distribution of the target cross-section of the concrete structure in terms of the amount of shrinkage over time acquired by the acquisition unit 100 by multiplying the amount of change in the target distribution in the target cross-section of the concrete structure, which is the amount of change per unit shrinkage of the concrete structure, by a predetermined coefficient.

[0036] The estimation unit 102 can estimate, for example, that if a change in X occurs in the target distribution of the target cross-section due to a time-dependent shrinkage Y that occurs from one reference time to another, then the change in the target distribution of the target cross-section when a time-dependent shrinkage of 10Y occurs from that reference time is 10X. Note that X may be a two-dimensional vector in which each element represents the stress at a certain coordinate.

[0037] —Estimation of target distribution when concrete structures are composed of multiple layers— When concrete structures are poured in stages, the concrete structure may have members with different ages or different amounts of shrinkage over time due to different free strains. For such concrete structures, the estimation unit 102 may estimate the target distribution for each member.

[0038] Specifically, if a concrete structure is composed of an existing structure, a first concrete body poured into the existing structure, and a second concrete body poured into the first concrete body, along the direction of the target cross-section, the estimation unit 102 can estimate at least one of the strain distribution and stress distribution in the target cross-section of the concrete structure, assuming that the first concrete body is at a first age and the second concrete body is at a second age different from its first age.

[0039] Furthermore, in this case, the estimation unit 102 may estimate the target distribution by assuming that in adjacent members, such as an existing structure and the first concrete body, or the first concrete body and the second concrete body, one member restrains the contraction or expansion of the other member.

[0040] In this embodiment, examples are given of cases where the concrete structure includes a first concrete body and a second concrete body, but the concrete structure is not limited to two concrete bodies and may include more than two concrete bodies. The various methods according to this embodiment when the concrete structure includes a first concrete body and a second concrete body can also be extended to cases when the concrete structure includes three or more concrete bodies.

[0041] The estimation unit 102 can estimate the target distribution in the target cross-section based on the method described in "<Theory concerning System 1>" which will be described later.

[0042] <<Judgment unit 104>> When the estimation unit 102 estimates the stress distribution in the target cross-section, the determination unit 104 determines, based on that stress distribution, whether the tensile force acting on at least a portion of the target cross-section exceeds a predetermined threshold. The predetermined threshold can be obtained by the acquisition unit 100 described above.

[0043] In one embodiment, the predetermined threshold is a value at which cracks may occur in the concrete structure. That is, the determination unit 104 can determine whether or not cracks will occur in the concrete structure based on the estimation result by the estimation unit 102. In this case, the predetermined threshold can be analytically determined based on the specifications of the concrete structure. Specifically, assuming that a tensile stress exceeding the tensile strength is a condition for cracking, the tensile strength of a test piece obtained with the same composition and curing as the concrete structure may be adopted as the predetermined threshold. Alternatively, for the sake of redundancy, a value lower than the tensile strength may be used as the threshold.

[0044] Furthermore, the determination unit 104 may determine the age at which cracks occur by calculating in reverse the age at which the strain reaches a predetermined threshold (tensile strength). In another embodiment, the age at which cracks occur output in this manner may be a value used to determine whether maintenance (including rebuilding, etc.) of the concrete structure should be carried out.

[0045] ≪Decision Section 106≫ The determination unit 106 determines information regarding the expansive agent to be added when producing the concrete structure, based on the determination result from the judgment unit 104. If too little expansive agent is added, the concrete structure may crack due to shrinkage over time before the member reaches the desired service life. On the other hand, if too much expansive agent is added, it will result in extra costs and may generate undesirable tensile forces on other structures that the concrete structure restrains. The determination unit 106 may also determine information regarding a shrinkage reducing agent instead of an expansive agent.

[0046] In one embodiment, if the determination unit 104 determines that the tensile force acting on at least a portion of the target cross-section of the concrete structure exceeds a predetermined threshold, the determination unit 106 may determine that the amount of expansive material to be added when producing at least a portion of the concrete structure should be increased. For example, if it is estimated that cracks or the like may occur in the concrete structure before the member reaches a desired service life, the determination unit 106 may determine that the amount of expansive material to be added when producing the concrete structure should be increased.

[0047] In one embodiment, if the determination unit 104 determines that the tensile force acting on all parts of the target cross-section of the concrete structure does not exceed a predetermined threshold, the determination unit 106 may determine information that the amount of expansive material to be added when producing at least a portion of the concrete structure should be reduced. For example, if it is estimated that no cracks or the like will occur in the concrete structure even when the age of the member reaches a desired service life, the determination unit 106 may determine information that the amount of expansive material to be added when producing the concrete structure should be reduced.

[0048] In one embodiment, the determination unit 106 determines information regarding the expansive material to be added when producing a concrete structure, based on the estimated stress distribution in the target cross-section of the concrete structure assuming that at least a first amount of expansive material is added, and the estimated stress distribution in the target cross-section of the concrete structure assuming that a second amount of expansive material is added. The determination unit 106 may perform estimations based on multiple amounts of expansive material until an amount is found in which cracks or the like do not occur in the concrete structure even when the age of the member reaches the desired service life.

[0049] Furthermore, if a concrete structure is composed of, for example, a first concrete body and a second concrete body poured into the first concrete body, adding an expansive agent to the first concrete body may increase the tensile force acting on the second concrete body that restrains the first concrete body. This is expected to make the second concrete body more susceptible to cracking and other damage. In other words, the amount of expansive agent to be added when producing a concrete structure may need to be determined by the combination of the amount of expansive agent to be added when producing the first concrete body and the amount of expansive agent to be added when producing the second concrete body.

[0050] Therefore, in one embodiment, if the concrete structure is composed of an existing structure, a first concrete body poured into the existing structure, and a second concrete body poured into the first concrete body, along the direction of the target cross-section, the determination unit 106 can determine, as information regarding the expansive material to be added when producing the concrete structure, information regarding the expansive material to be added when producing the first concrete body and the second concrete body, respectively.

[0051] For example, when a concrete structure is composed of a first concrete body and a second concrete body poured into the first concrete body, the estimation unit 102 determines the amount of expansive material to be added when producing the first concrete body, X1, ..., X N Assuming that the amount of expansive agent to be added when producing the second concrete body is Y1, ..., Y M X n and Y m The stress distribution in the target cross-section may be estimated for at least some of the combinations (where n=1, ..., N and m=1, ..., M). The determination unit 106 may then determine the amount of expansion material to be added based on the estimation results.

[0052] In one embodiment, the determination unit 106 may determine information regarding the lower limit (in one example, the minimum amount of expansive material that does not cause the first concrete body itself to crack) and upper limit (in one example, the maximum amount of expansive material that does not cause the second concrete body that restrains the first concrete body to crack) of the amount of expansive material that should be added when producing the first concrete body, and information regarding the lower limit and upper limit of the amount of expansive material that should be added when producing the second concrete body.

[0053] In another embodiment, the determination unit 106 determines that X is not cracked in either the first concrete body or the second concrete body, as determined by the determination unit 104. n and Y m From the combination, X n +Y m The combination that minimizes this (i.e., the minimum amount of expansive material in the range where no cracks occur) may be determined.

[0054] <<Output section 108>> The output unit 108 outputs suggested information regarding parameters for designing a concrete structure when the determination unit 104 determines that the tensile force acting on at least a portion of the target cross-section exceeds a predetermined threshold.

[0055] In one embodiment, the proposed information includes information about an expansive material to be added when producing a concrete structure, as determined by the determination unit 106. If the determination unit 106 determines information about an expansive material to be added when producing a first concrete body and a second concrete body, respectively, the output unit 108 may output that information.

[0056] In one embodiment, the proposed information includes information regarding the shape of the concrete structure. For example, if the determination unit 104 determines that cracks or the like may occur in the concrete structure before the age of the member reaches a desired service life, the output unit 108 may output proposed information that includes information indicating that the thickness of the concrete structure should be increased.

[0057] (Storage unit 12) The memory unit 12 stores various information necessary for the operation of the information processing device 2. For example, the memory unit 12 stores various programs that the control unit 10 will execute.

[0058] (Network interface section 14) The network interface unit 14 enables communication with other devices via the communication network 4.

[0059] [Terminal device 3] Terminal device 3 is a device used by a person who designs concrete structures (hereinafter referred to as the "user"). Terminal device 3 may be a communication device equipped with a user interface and a communication interface, such as a personal computer, smartphone, or tablet terminal. In this case, terminal device 3 may be equipped with input devices (e.g., mouse, keyboard, touch panel, camera, and microphone, etc.) and output devices (e.g., display and speaker, etc.). Terminal device 3 can communicate with other devices by running an application such as a web browser.

[0060] In this embodiment, the information processing device 2 and the terminal device 3 are described as separate devices, but this is not limited to them. Specifically, at least some of the functions of the information processing device 2 described in this disclosure and at least some of the functions of the terminal device 3 may be implemented on a single device.

[0061] [Communication Network 4] The communication network 4 enables communication between the information processing device 2 and the terminal device 3. The communication network 4 enables communication based on the TCP / IP protocol, for example.

[0062] <Example of operation of information processing device 2> An example of the operation of the information processing device 2 will be explained with reference to Figure 2-3. Figure 2 is a flowchart illustrating an example of the operation of the information processing device 2. In the following example, we will explain an example in which the information processing device 2 estimates the stress distribution of the target cross-section.

[0063] First, the information processing device 2 acquires information regarding the shape of the concrete structure (S100). Next, the information processing device 2 acquires information regarding the amount of expansive material to be added to the concrete structure (S102). Next, the information processing device 2 acquires information regarding the age of the members of the concrete structure (S104). Next, the information processing device 2 acquires the initial value of the stress in the target cross-section (S106). The information processing device 2 may acquire this information from the terminal device 3.

[0064] Next, the information processing device 2 sets the variable n to "1" (S108). Then, based on the information acquired in S100-S104, the information processing device 2 calculates the stress increment during the nth period (at this point, the first period) and adds it to the initial stress value acquired in S106 (S110).

[0065] Next, the information processing device 2 determines whether the member has reached the age acquired in S104 by the nth period (S112). If it is determined that the member has not reached the age by the nth period (S112 NO), the variable n is incremented (S114), the stress increment for the next period is further calculated, and added to the calculation results obtained up to that point (S110). In each period, the stress increment is calculated based on the Young's modulus and the amount of shrinkage per unit time corresponding to that period.

[0066] On the other hand, if it is determined that the member has reached its age by the nth period (S112 YES), the iterative calculation is terminated, and the stress distribution of the concrete structure is estimated based on the result of the most recent S110 (S116).

[0067] Next, the information processing device 2 determines whether or not there are any locations within the target cross-section where a tensile force exceeding a predetermined threshold is acting (S118). If it is determined that there are locations within the target cross-section where a tensile force exceeding a predetermined threshold is acting (S118 YES), the information processing device 2 changes the information regarding the amount of expansive material obtained in S102 (S120), and then performs the estimation of the stress distribution within the target cross-section again in that case (S106-S116).

[0068] On the other hand, if it is determined that there are no locations within the target cross-section where a tensile force exceeding a predetermined threshold is acting (S118 NO), the information processing device 2 outputs the amount of expansive material to be added to the concrete structure (S122). Specifically, if the information processing device 2 determines "YES" at least once in S118, it outputs the amount of expansive material changed in the most recent S120, and if it does not determine "YES" at all in S118, it outputs the amount of expansive material obtained in S102.

[0069] In this configuration, the information processing device 2 calculates the stress increment based on the Young's modulus for each period and the amount of shrinkage per unit time, and estimates the final stress distribution based on the sum of these increments over the entire period. This makes it possible to estimate the stress distribution that takes into account the changes in the concrete structure over time.

[0070] Figure 3 is a flowchart illustrating another example of the operation of the information processing device 2.

[0071] First, the information processing device 2 acquires information regarding the shape of the concrete structure (S200). In this example, the concrete structure is composed of a first concrete body and a second concrete body.

[0072] Next, the information processing device 2 acquires information regarding the amount of expansive agent to be added to the first concrete body and the second concrete body, respectively (S202). Next, the information processing device 2 acquires information regarding the age of each member of the first concrete body and the second concrete body (S204). In this example, the age of the members of the first concrete body is assumed to be "5 years", and the age of the members of the second concrete body is assumed to be "2 years".

[0073] Next, the information processing device 2 obtains the initial stress value in the target cross-section of the first concrete body (S206). Then, the information processing device 2 performs the same iterative calculation as in S108-S114 in Figure 2. However, in the example in Figure 2, the information processing device 2 determined whether or not the member had reached its age by the nth period, but in this example, it determines whether or not "3 years" (the difference between the age of the member of the first concrete body, which is "5 years", and the age of the member of the second concrete body, which is "2 years") has been reached by the nth period (S212).

[0074] Next, the information processing device 2 obtains the initial stress values ​​at the target cross-section of the concrete structure after the second concrete body has been poured (S216). Subsequently, iterative calculations are performed for each period (S218-S222), and if "5 years" have been reached by the nth period, the final stress distribution of the concrete structure is estimated (S224).

[0075] In summary, the information processing device 2 estimated the stress distribution of the members of the first concrete structure until the age reached "3 years" through iterative calculations from S208 to S214. Subsequently, the information processing device 2 estimated the stress distribution when the age of the members of the first concrete structure reached "5 years" and the age of the members of the second concrete structure reached "2 years" through iterative calculations from S218 to S222.

[0076] This configuration allows for the estimation of stress distribution with high accuracy, even when the concrete structure is composed of multiple layers of concrete.

[0077] Note that the operations described in the example of FIGS. 2-3 are merely examples of the operations of the information processing apparatus 2 and can be appropriately changed based on the content of the present disclosure and the knowledge possessed by those skilled in the art.

[0078] <Example of display screen by information processing apparatus 2> Referring to FIGS. 4-5, an example of a display screen by the information processing apparatus 2 will be described. Note that the symbols (e.g., "○○" and "△△", etc.) in the example of the display screen are merely for conceptually indicating the displayed content, do not indicate specific values, and do not limit the content of the present disclosure. Also, in the following example of the display screen, an example in which the information processing apparatus 2 estimates the stress distribution of the target cross-section will be described.

[0079] FIG. 4 shows an example of a display screen when the estimation result by the information processing apparatus 2 is displayed on the terminal device 3. In the example of the display screen of FIG. 4, a simulation setting display area D10, a result display area D12, a proposal information display area D14, a stress distribution D15, a detailed confirmation button D16, and a setting change button D18 are displayed.

[0080] In the simulation setting display area D10, the settings (which can also be called simulation settings / simulation conditions) used in estimating the stress distribution are displayed. In the result display area D12, the estimation result is displayed. In this example, as the estimation result, "Cracking occurs × days after the first concrete placement" is displayed.

[0081] In the proposal information display area D14, information regarding the expansion material to be added when producing the concrete structure is displayed. In this example, as that information, "The amount of expansion material that does not cause cracking" is "[First concrete body: △△ kg / m 3 Second concrete body: △△ kg / m 3 " is displayed.

[0082] The stress distribution D15 displays the stress distribution estimated by the information processing device 2. The stress distribution D15 may also indicate locations where cracking is determined to occur, based on the estimated stress distribution.

[0083] The detailed confirmation button D16 is used to transition to a screen that displays detailed results of the stress distribution estimation. An example of the destination screen will be shown later in Figure 5.

[0084] The settings change button D18 is a button that takes you to a screen where you can change the simulation settings.

[0085] Figure 5 shows another example of the display screen when the estimation results from the information processing device 2 are displayed on the terminal device 3. The example display screen in Figure 5 shows the first estimation result D20, the second estimation result D22, and the third estimation result D24.

[0086] The first estimation result D20 shows the estimation result based on the simulation settings set by the user (see simulation settings display area D10 in Figure 4). The second estimation result D22 shows the estimation result when the amount of expansive agent is autonomously changed after the first estimation. The third estimation result D24 shows the estimation result when the amount of expansive agent is further autonomously changed after the second estimation. In other words, the example display screen in Figure 5 shows that three simulations were performed to determine the amount of expansive agent necessary to prevent cracking in the concrete structure.

[0087] <Hardware Configuration> Referring to Figure 6, an example of a hardware configuration when the devices included in System 1 described above are implemented by computer 70 will be explained. Note that the functions of each device can also be implemented by dividing them among multiple devices.

[0088] As shown in Figure 6, the computer 70 includes a processor 700, a storage device 702, an input interface 704, a data interface 706, a communication interface 708, and a display device 710.

[0089] The processor 700 controls various processes in the computer 70 by executing programs stored in the storage device 702. For example, each functional unit of the control unit 10 of the information processing device 2 can be realized by the processor 700 executing programs stored in the storage device 702.

[0090] The storage device 702 is a storage medium such as RAM (Random Access Memory). RAM temporarily stores the program code of the program executed by the processor 700, as well as data required during program execution.

[0091] The storage device 702 can also be a non-volatile storage medium such as a hard disk drive (HDD) or flash memory. The storage device 702 stores the operating system and various programs for realizing the above configurations. The storage medium storing these various programs may be a non-transitory computer-readable medium. In addition, the storage device 702 can also store tables for registering various information and a database for managing those tables. Such programs and data are loaded into the storage device 702 as needed and accessed by the processor 700.

[0092] The input interface 704 is a device for receiving input from the user. Specific examples of the input interface 704 include cameras, buttons, microphones, keyboards, mice, touch panels, various sensors, and wearable devices. The input interface 704 may be connected to the computer 70 via an interface such as USB (Universal Serial Bus).

[0093] The data interface 706 is a device for inputting data from outside the computer 70. Specific examples of the data interface 706 include drive devices for reading data stored on various storage media. The data interface 706 may also be located outside the computer 70. In that case, the data interface 706 would be connected to the computer 70 via an interface such as USB.

[0094] The communication interface 708 is a device for performing data communication with external devices of the computer 70 via the communication network 4, either by wire or wireless connection. The communication interface 708 may also be located outside the computer 70. In that case, the communication interface 708 would be connected to the computer 70 via an interface such as USB.

[0095] The display device 710 is a device for displaying various types of information. Specific examples of the display device 710 include liquid crystal displays, organic EL (Electro-Luminescence) displays, and displays for wearable devices. The display device 710 may be located outside the computer 70. In that case, the display device 710 is connected to the computer 70 via, for example, a display cable. Furthermore, if a touch panel is used as the input I / F 704, the display device 710 can be configured as an integrated unit with the input I / F 704.

[0096] Furthermore, the components of the device included in the System 1 described above are such that a program stored in the storage device 702 is executed by the processor 700, thereby realizing a defined process in cooperation with other hardware. In other words, these components are conceived as both software or firmware, and as corresponding hardware, and in both concepts, they may be described and interpreted as "function," "means," "part," "processing circuit," "unit," or "module," etc.

[0097] <Theory concerning System 1> System 1 described in the above embodiments may be implemented and / or extended based on the following theory. The following theory does not limit the scope of this disclosure.

[0098] [1. Axial cross-sectional analysis of a CPC member without an axis of symmetry] ((1) Model of equilibrium conditions for a cross-section after age Δt has elapsed) A method according to one aspect of this disclosure comprises the steps of (1) calculating an equilibrium plane that satisfies the equilibrium conditions for forces acting in the axial direction of the cross section and the equilibrium conditions for moments in the x direction (width direction of the cross section) and y direction (height direction of the cross section), using the amount of change in free strain of each member as Δt elapsed from an arbitrary age as input values, and (2) calculating the stress and strain at an arbitrary position within the cross section by accumulating the obtained amounts of change in stress and strain within the cross section over time.

[0099] The change in free strain over a period of Δt can be calculated using experimental values, empirical formulas, or formulas specified in each standard. Furthermore, the stress-strain relationship for each member can be calculated using elastic calculations based on Hooke's Law, as well as constitutive laws such as the assumption of constant work rate used to calculate the chemical prestress of expansive concrete. When using the assumption of constant work rate as a constitutive law for stress-strain, the input value should be the constrained expansion strain from a uniaxial constrained expansion test, not the free strain of the expansive concrete.

[0100] Figure 7 shows a conceptual diagram of the equilibrium conditions for the provided model. Figure 7(a) schematically shows from the first lift to the final i-lift. As shown in Figure 7(b), the first and second lifts, which were poured earlier, illustrate the contraction process, while the final i-lift illustrates the expansion process of the expanding concrete. When each member is integrated, the assumption of plane maintenance holds, and the expansion of the expanding concrete in the i-lift is restrained by the contracting existing concrete and the reinforcing bars inside the concrete, satisfying the equilibrium conditions for forces and moments in the equilibrium plane shown in Figure 7(c). The equilibrium plane in Figure 7(c) is the change in free strain Δε when the age has elapsed by Δt. f In contrast, Δε is the change in strain distribution that satisfies the equilibrium condition when each member acts as a whole. r This plane is one in which the plane is maintained, satisfying the equilibrium conditions for force and moment. The change in the amount from the free strain in Figure 7(b) to the strain that satisfies the equilibrium conditions in Figure 7(c) is the effective strain, which is converted into stress.

[0101] The conditions for force equilibrium are shown in Mathematics 1.

[0102]

number

[0103] Here, i: lift number, j: rebar number in lift i, Δσ c(x , y) : Change in stress (N / mm²) of concrete at position (x, y) after Δt has elapsed. 2 ), A ci :i Cross-sectional area of ​​the concrete lift (mm²) 2 ), Δσ sij Δt is the change in stress of the j-th reinforcing bar at the i-lift. The first term in parentheses is the change in stress of the concrete at the i-lift over a small area ΔA. ciThe first term is the sum of the products of the forces acting on the concrete. The second term is the sum of the changes in stress on the reinforcing bars at the i-lift, representing the resultant force acting on the reinforcing bars. Equation 1 is the force equilibrium condition where the sum of these resultant forces across all lifts is zero.

[0104] The conditions for the equilibrium of moments are shown in equations 2 and 3. Equation 2 is the equilibrium condition for moments around the x-axis, and equation 3 is the equilibrium condition for moments around the y-axis.

[0105]

number

number

[0106] Change in concrete stress Δσ from Math 1 to Math 3 c(x , y) This varies depending on the constitutive law applied. This will be shown in the next section.

[0107] ((2) Stress-strain relationship) The stress-strain relationship for existing concrete and reinforcing steel is obtained by applying elastic calculations based on Hooke's Law, resulting in equations 4 and 5, respectively.

[0108]

number

number

[0109] Here, E ci :i Lift concrete at age t day (N / mm 2 ), E sij :i lift Young's modulus of the jth reinforcing bar (N / mm 2 ), Δε c(x , y): This is the strain (change in constraint strain) in the equilibrium plane at position (x, y).

[0110] In the existing concrete shown in Equation 4, as shown in Figures 7(b) and (c), although it would normally change by the amount of free strain, it is constrained and equilibrium in the equilibrium plane. Therefore, the difference becomes the effective strain. Multiplying this by the Young's modulus of the concrete at age t day gives the amount of stress change. On the other hand, the reinforcing bars (steel materials) shown in Equation 5 do not change in volume due to themselves, so their own Δε f This becomes zero, and omitting this gives us the number 5.

[0111] The expansion process of CPC members using expansive concrete can be assumed to involve constant work, in which case equation 6 is used.

[0112]

number

[0113] Here, U: the amount of work done by the expanding concrete per unit volume against the constraint (N / mm²) 2 For example, it can be determined from the rate of change in length of the uniaxial confinement expansion test in Annex B of JIS A 6202 Concrete Expansion Agents. The amount of work done by expanding concrete per unit volume on a confinement body such as confinement steel is, within a practical range, approximately constant regardless of the amount of reinforcing steel and the degree of confinement such as the arrangement of reinforcing steel, provided that the concrete mix and curing method are the same. The amount of work U done by expanding concrete per unit volume on a reinforcing steel confinement body is expressed by Equation 7. Equation 6 is a modified version of Equation 7 with a changed symbol to match the model provided in this disclosure.

[0114]

number

[0115] Here, σ c Chemical prestress (N / mm²) introduced into expansive concrete 2 ), ε r: Expansion strain of expansive concrete, ε s : Chemical press train of the expansion strain (tensile strain) of reinforcing steel, and the expansion strain of the expanding concrete at that location ε r It is equal to.

[0116] ((3) Change in strain of the equilibrium plane) Assuming all lifts are integrated, plane preservation is achieved and an equilibrium plane is obtained, as shown in Figure 7(b). As shown in Figure 7, if the width direction is x and the height direction is y, the change in strain is Δε. c(x , y) This becomes the plane equation of equation 8.

[0117]

number

[0118] Here, A is Δε c(x , y) The inclination of the plane in the x-direction, B, is Δε c(x , y) The inclination of the plane in the y-direction, C, is Δε. c(x , y) It is a cross-section of a plane.

[0119] In the actual solution, we will solve for the coefficients A, B, and C, which are unknowns in equation 8 that simultaneously satisfy the three equilibrium conditions shown in equations 1 through 3. A, B, and C can be identified through iterative calculations such as the squeeze theorem.

[0120] (4) Examples concerning the application of constitutive rules) Figure 8-10 illustrates a typical calculation example for a three-lift system consisting of existing and newly constructed sections.

[0121] Figure 8 shows the case where the newly constructed expansive concrete A is constrained by the existing ordinary concrete. Figure 9 shows an example where the newly constructed expansive concrete B is poured on top of the newly constructed A, resulting in both the existing and newly constructed concrete being constrained. Figure 10 shows the case where all lifts are in the contraction phase. Note that all are reinforced concrete with internal reinforcing bars. In Figures 8-10, A corresponds to ages t1, t2, and t3 shown in Figure 11, and Δε is the change in free strain (unconstrained strain) when the existing and newly constructed concrete behave independently without being constrained, after Δt has elapsed from that age. f This is shown. In Figure 8-10, the subscripts a, b, and c represent existing, new A, and new B, respectively. Similarly, in Figure 11, the subscripts 1, 2, and 3 represent existing, new A, and new B, respectively.

[0122] Figure 8-10, part B, shows the case where the existing and new structures behave as a single unit after a similar age of Δt, and plane stability is achieved. In Figure 8, the existing structure, which is contracting, constrains the expansion of the new structure A, resulting in equilibrium. The constitutive laws applied are Hooke's Law (Equation 4) for the existing concrete section and the constant work rate assumption (Equation 6) for the expanding concrete of the new structure A. Next, Figure 9 shows the phase where the contracting new structure A and the existing structure are constrained and in equilibrium with the expansion of the new structure B. Hooke's Law is applied to the existing structure and new structure A, which are in the contraction phase, and the constant work rate assumption is applied to the expanding new structure B. Figure 10 shows the case where all parts are in the contraction phase, and Hooke's Law is applied to all of them. In this way, the constitutive laws of stress and strain are applied according to the phase of volume change.

[0123] ((5) Calculation of stress and strain within the cross-section) (3) Using A, B, and C obtained in Section (3), the change in stress and the change in strain of the concrete and reinforcing bars within the cross-section can be calculated from Equations 4, 5, and 6. Then, the strain ε c (x , y) and stress σ c (x , y) , σ sij This is the obtained strain change Δε c (x , y) and the change in stress Δσ c (x ,y) , Δσ sij This is the cumulative sum over time. That is, it is calculated using numbers 9, 10, and 11.

[0124]

number

number

number

[0125] [2. Experiments with CPC members without an axis of symmetry] ((1) Experiment Overview) (a) Test specimen Figure 12A shows a cross-sectional view of the test specimen, and Figure 12B shows a plan view. The test specimen was a simulated bridge consisting of a concrete deck slab and wall parapets restrained by a 10m long steel girder. The asymmetry of the cross-section was reproduced by pouring the concrete for one of the wall parapets, then waiting a while before pouring the concrete for the other wall parapet. 6) .

[0126] Figure 12C shows an overview of the concrete pouring procedure. The steel girders in the axial direction of the bridge consist of two H-shaped steel beams, each 10m long and measuring H400×400×13×21mm, with a girder spacing of 2.5m. These steel girders are placed on four transverse girders, but to minimize the influence of the transverse girders' constraints, Teflon® sheets were installed between the steel girders to create a separation.

[0127] Three φ16mm x 160mm stud dowels were placed on the top surface of the steel girder at 1000mm intervals. On top of this steel girder, a reinforced concrete deck slab with the same structure as the actual bridge, measuring 4100mm in width, 10,000mm in length, and 220mm in thickness, was poured. Water curing using curing mats was carried out for 14 days, and the formwork was removed on the 28th day after formation.

[0128] Ninety days after the concrete slab was poured, the concrete for one of the two wall parapets, which had a cross-sectional shape and reinforcement arrangement that was generally used in practice, was poured first. After a 28-day gap, the concrete for the remaining wall parapet was poured. Hereafter, the wall parapet that was poured first will be referred to as "first-poured," and the wall parapet that was poured later will be referred to as "second-poured." As it was winter, the wall parapets were cured using a damp covering method with insulating sheets and blue tarpaulins. The curing period was 14 days, after which they were exposed to the outside air.

[0129] For the test specimens, D16 reinforcement was used in the bridge axial direction for the deck slab and D13 reinforcement for the wall parapets. Details regarding the reinforcement perpendicular to the bridge axis are described in reference (6) below and are therefore omitted here. A total of two test specimens were prepared. The experimental factors were the volume changes of the pre-cast and post-cast concrete in the deck slab and wall parapets that constitute the test specimens, and these were controlled by changing the unit amount of the expansive agent described later.

[0130] ≪(b) Measurement items≫ The measurement items were the strain of the reinforcing bars in the bridge axial direction and the strain of the steel girders, measured using a wire strain gauge (hereinafter referred to as WSG) with a gauge length of 6 mm. Figure 12 shows the installation locations of the WSGs. For reference, embedded strain gauges were also installed at the center of the wall parapet and deck slab.

[0131] The purpose of this experiment was to verify a method for estimating strain and stress distribution in an asymmetrical cross-section; therefore, it was necessary to eliminate the influence of stress release due to the occurrence of shrinkage cracks. For this reason, a shrinkage joint was provided in the parapet wall at the central position in the bridge axis direction. As a result, the AA and BB cross-sections in the figure are under the same conditions in terms of shape and dimensions, and the aim was to improve the accuracy of the experiment by increasing the number of cross-sections (n).

[0132] Furthermore, JIS test specimens were prepared simultaneously with the actual bridge test specimens using the same mixture and curing conditions. A WSG (Weighing Strain Generator) was then installed on the JIS test specimens, just as it was on the actual bridge test specimens, to measure strain.

[0133] (c) Experimental standards and concrete mix design The experimental factors were the rate of change in the length of the concrete in each component of the specimen, and the unit amount of expansive concrete was varied. Figure 13 shows the concrete mix and its combinations.

[0134] Cement has a density of 3.16 g / cm³. 3 Ordinary Portland cement is used, and the fine aggregate has a density of 2.56 g / cm³. 3 This river sand is from Seto City, Aichi Prefecture, and has a density of 2.67 g / cm³. 3 The crushed sand from Nukata District, Aichi Prefecture, is used as coarse aggregate, with a density of 2.67 g / cm³. 3 The crushed stone 2010 and crushed stone 1505 from Nukata-gun, Aichi Prefecture are used, and the expansive material has a density of 3.10 g / cm³. 3 Type 20 (standard usage is 20 kg / m³) 3 The ettringite-lime composite was used. In addition, AE water-reducing agent standard type (Type I) was used as an admixture. All concretes were slub The pump was adjusted to 12.0 ± 2.5 cm, and the air volume to 4.5 ± 1.5%.

[0135] By applying the analytical method provided in this disclosure and repeatedly performing preliminary analyses with the expansion rate of the concrete of each member as a factor, it was confirmed that when expansive concrete with a high expansion rate is used for the later-cast concrete, the pre-cast concrete, which acts as a constraint, is subjected to tensile stress as a reaction force to the expansion of the later-cast concrete. Therefore, in specimen II, in order to compensate for the compressive stress that disappears as a reaction force to the expansion constraint of the later-cast concrete, the pre-cast concrete was designed with a mix of expansive concrete with a high expansion rate. Furthermore, expansive concrete was used for the concrete of the floor slab of specimen II with the aim of eliminating the influence of crack generation due to shrinkage on the shrinkage behavior of the wall parapet, which is the subject of evaluation.

[0136] ((2) An example of experimental results) Figure 14 compares experimental and calculated values ​​of the strain of reinforcing bars in the axial direction of the bridge. It is shown for three parts: the deck slab, the pre-cast and post-cast sections of the wall parapet. The legend for each figure includes symbols for the reinforcing bar positions with WSGs attached, as shown in Figure 12. For the deck slab, S3 is shown on the pre-cast side of the lower section, S5 in the center, and S7 on the post-cast side. For the wall parapet, W3 is shown at the upper section, W2 at the middle section, and W1 at the lower section, all located on the outer side, for both pre-cast and post-cast sections. These are located at 185 mm, 525 mm, and 895 mm from the top edge of the wall parapet, respectively. The age on the horizontal axis is taken from the time the deck slab was cast, with the pre-cast section of the wall parapet being 90 days old and the post-cast section being 118 days old. The various calculation formulas used to determine the calculated values ​​and their input conditions are shown in the appendix. For the calculation formulas for compressive strength, tensile strength, Young's modulus, and expansion strain, the constants were identified using the least squares method to reproduce experimental values ​​from test pieces that underwent the same curing process as the specimen. For shrinkage strain, the method shown in the 2022 Standard Specifications for Concrete [Design Edition] (hereinafter referred to as "JSCE Specifications Design Edition") was adopted.

[0137] ≪(a) Test specimen I≫ The behavior of specimen I will be summarized in comparison with the calculated values. Figure 14 shows ordinary concrete. The strain of the floor slab to which this method was applied, up to 90 days of age when the lumber is first cast, is 0 to -50 × 10, although affected by daily fluctuations and other factors. -6The deformation shifted towards contraction within a certain range. Subsequently, the pre-casting of expansive concrete constrained the expansion of the pre-cast concrete, and calculations showed that the strain on the pre-cast side of the slab shifted to the tensile side, decreasing as it moved towards the later-cast side. On the other hand, experimental values ​​did not show any significant change in strain in the slab around 90 days after the pre-casting, but when compared with the data of the subsequent contraction process, the strain on the pre-cast side of the slab was greatest on the expansion side, shifting to the contraction side in the order of the center of the slab and the later-cast side, and a clear difference in strain depending on the horizontal position of the slab was observed, similar to the calculations. Furthermore, since ordinary concrete was used for the later-cast wall railings cast at 118 days of age, no increase or decrease in strain due to the later casting was observed, and the difference in strain due to the pre-casting continued unchanged until 540 days of age.

[0138] In the pre-cast parapet wall using expansive concrete, the expansion strain was smaller on the lower section where the degree of constraint of the floor slab was greater, and larger on the upper section where the degree of constraint was less. The calculated values ​​are slightly smaller than the experimental values, but considering subsequent shrinkage, we believe that the evaluation is on the safe side. In the post-cast parapet wall using ordinary concrete, although the absolute value depends on the input value from the JSCE Design Specifications, the behavior during shrinkage was smaller on the lower section of the parapet wall where the degree of constraint of the floor slab was greater, and larger on the upper section where the constraint was less. Although differences such as daily variations are observed, it can be said that the relative behavior of the experimental values ​​is reproduced.

[0139] ≪(b) Specimen II≫ The floor slab, to which expansive concrete was applied, had a symmetrical cross-section until the wall railings were poured, resulting in a constant expansion strain in the width direction, which generally agreed with the calculated values. Subsequently, with the pouring of the wall railings at 90 days of age, the calculated values ​​showed that the floor slab on the first-poured side experienced greater tensile expansion, and this effect decreased towards the later-poured side. While the experimental values ​​did not show such a large difference as the calculated values, the general trend in magnitude was confirmed. Furthermore, with the later-poured wall railings poured at 118 days of age, the strain on the later-poured floor slab was subjected to tensile stress, and the calculated values ​​showed that the entire floor slab had a uniform strain distribution. On the other hand, the experimental values ​​showed that the strain on both the first-poured and later-poured sides was uniform, similar to the calculated values, but the strain in the center of the floor slab was larger, suggesting that the center of the floor slab exhibited deformation such as warping in the axial direction. The left and right sides of the floor slab's cross-section are wall railings and steel girders, which provide external constraints in the height direction. However, there are no such constraints in the center of the floor slab, and it is presumed that the center of the floor slab was displaced in the height direction, resulting in large axial strain.

[0140] During the subsequent contraction, the strains, except for the center of the floor slab, were plotted on the same line as the calculated values, albeit with some differences in absolute values, suggesting that the experimental behavior was successfully reproduced.

[0141] The strain of the wall railings constructed first tended to be smaller in the lower section where the degree of constraint was greater, and larger in the upper section where the degree of constraint was less, which generally reproduced the calculated values. Furthermore, the strain of the wall railings constructed later also largely reproduced the calculated values, except that the experimental values ​​for the strain of the upper section of the wall railing tended to be larger than the calculated values.

[0142] (c) Summary Experiments were conducted to recreate cross-sections without an axis of symmetry during the construction process, such as when casting wall railings one side at a time, and to vary the volume change of each member using expansive concrete. As a result, it was confirmed that strain distributions corresponding to asymmetry are created in the height and width directions of the cross-section. Furthermore, it was confirmed that the calculated values ​​using the cross-sectional analysis method without an axis of symmetry provided in this disclosure can generally reproduce the behavior of the experimental values. However, the difference between the experimental and calculated values ​​suggests that, in the case of large structures like this one, the constraint in the height direction of the cross-section also has a considerable influence. This is one of the issues to be investigated in the future.

[0143] [3. Stress] The comparison between the experimental values ​​(black lines in each graph in Figure 14) and the calculated values ​​(gray lines in each graph in Figure 14) shows that the calculated values ​​can generally reproduce the experimental values. Based on these calculated values, the results of calculating the stress in the bridge axis direction are shown in Figure 15, and an example of a stress distribution contour plot is shown in Figure 16. Figure 15 also includes the calculated tensile strength values.

[0144] In specimen I, the stress generated in the floor slab was due to the pre-casting of expansive concrete for the wall railing. This resulted in a distribution where the tensile stress of S3 on the pre-cast side was large, and S7 on the post-cast side was small.

[0145] In pre-cast concrete application using expansive concrete, the lower side, where the degree of restraint of the deck slab is greater, exhibits a -2.0 N / mm² pressure due to the placement of the concrete. 2 The upper section, where the degree of constraint is smaller, has a resistance of -1.0 N / mm 2 Chemical prestress was introduced. During the subsequent shrinkage process, it can be seen that the tensile stress is high on the lower side where the constraint is greater, and decreases towards the upper side.

[0146] In the post-cast concrete application, the tensile stress distribution during the shrinkage process was high on the lower side where the deck slab was more constrained, and low on the upper side.

[0147] In specimen II, the floor slab had a load of 0.5 N / mm 2A certain degree of chemical prestress was introduced. As a reaction to the initial pouring of expansive concrete, tensile stress was generated on the initial pouring side. However, further pouring of the concrete afterward generated tensile stress on the later pouring side as well, resulting in a uniform stress state throughout the entire slab.

[0148] In the initial pouring, a large expansion force was introduced to account for the chemical prestress that would be lost as a reaction force from the expansive concrete poured later. As a result, tensile stress acted on the upper layer due to the later pouring, but the stress remained in the compressive range.

[0149] Furthermore, in the post-casting process, the chemical prestress was greater on the lower side where the degree of restraint on the floor slab was greater, and smaller on the upper side where the degree of restraint was less.

[0150] In both specimens I and II, the tensile strength was not exceeded in any part up to 540 days of age. It is presumed that no tensile stress is occurring. Furthermore, no significant cracks caused by stress in the bridge axis direction have been observed in the actual test specimens.

[0151] The effects of expansive concrete and the stresses generated by contraction are determined by the interrelationship between the target member and the member constraining it. By extending the cross-section to one without an axis of symmetry, it became clear that localized stress concentrations occurred not only in the target member but also in the reaction-generating constraining member. Appropriate evaluation and control of these relationships are desirable.

[0152] [4. Provision of a simple estimation method] ((1) Concept) The method described above takes the change in free strain of each member after a time Δt has elapsed from an arbitrary age as input values, calculates the equilibrium plane that satisfies the equilibrium conditions for forces acting in the axial direction of the cross section and the equilibrium conditions for moments in the width and height directions of the cross section, and calculates the stress and strain at any position within the cross section by accumulating the obtained changes in stress and strain within the cross section over time. However, the iterative calculation to find the equilibrium plane needs to be performed for each step of Δt.

[0153] On the other hand, under conditions where only the magnitude of the input strain changes, such as when the cross-sectional shape and mechanical properties of the object remain the same, the strain and the stress obtained through iterative calculation are proportional. Therefore, by multiplying the stress calculated using a unit strain as the input value by the ratio of an arbitrary strain to the unit strain, the change in stress corresponding to an arbitrary change in strain can be easily obtained, and iterative calculation can be omitted.

[0154] The simplified estimation method provided in this disclosure (hereinafter referred to as the "simplified method") calculates the change in stress for each member, divided into the pouring process and the subsequent shrinkage process, and estimates the stress by accumulating these results, similar to the method provided in this disclosure. In the pouring process, as shown in Figure 12C, the cross-sectional shape changes with each lift, so iterative calculations are performed for three steps: pre-pouring and post-pouring of the floor slab and wall parapet. In the subsequent shrinkage process, the strength of the concrete has fully developed and the Young's modulus can be assumed to be constant, so iterative calculations using unit strain can be applied. Therefore, the number of steps in the iterative calculation can be simplified to a total of four steps: three in the pouring process and once in the shrinkage process.

[0155] ((2) Calculation of stress during the driving process) Figure 17 summarizes the calculation examples of the change in stress and cumulative value during the casting process of floor slabs and wall railings using a simplified method, as well as the prediction of crack occurrence during the subsequent shrinkage process. The stress detection positions for each member were set at the upper and lower edges in the height direction, and 100 mm from the outermost left and right edges in the width direction.

[0156] Furthermore, in Figure 17, *1 to *6 correspond to the following items, respectively. *1: Stress detection locations were set at the upper and lower edges of each part in the height direction, and 100 mm from the outermost left and right edges in the width direction. *2: The numerical values ​​of the stress newly generated at each step are underlined. *3: During the shrinkage process, the post-casting of the wall railing is 100 × 10 as a unit strain. -6 The first shot was 95 x 10 -6 The floor slab is 65 x 10-6 The stress in the event of contraction was calculated. *4: The tensile strength was based on experimental values ​​obtained at 28 days of age. *5: This is the shrinkage strain when the stress due to shrinkage reaches the tensile strength. It was calculated using the following formulas: Post-construction E = (ft - C) × 100 ÷ D, Pre-construction E = (ft - C) × 95 ÷ D, and Floor slab E = (ft - C) × 65 ÷ D. *6: The age and drying shrinkage strain when the stress generated in the wall railing exceeds the tensile strength were predicted, and the age at which the strain in *5 occurs was calculated using the shrinkage strain calculation formula shown in Equation 4. If the calculation shows that the tensile strength has not been reached after more than 20 years, it is indicated as "20 or more". Parts subjected to compressive stress are indicated with "-".

[0157] The stress calculation during the concrete placement process involved three steps: pre-casting of the floor slab, pre-casting of the wall parapet, and post-casting. The equilibrium plane was determined through repeated calculations for each step, and the change in stress at each stage and its cumulative value were shown. In step 1, a unit strain of 100 × 10 was applied to the expansive concrete of the floor slab. -6 The expansion strain was applied, and the stress per unit strain was calculated by applying the assumption of constant work rate. The change in stress was calculated by multiplying this stress by the ratio of the desired strain to the unit strain (length change rate in Figure 13). Note that when ordinary concrete is used for the floor slab or when self-shrinkage is dominant in the concrete, the expansion strain can be treated as a negative value, allowing the assumption of constant work rate to be applied for convenience. Similarly, in step 2, the unit strain was applied to the pre-casting of the wall parapet, and in step 3, the unit strain was applied to the post-casting of the wall parapet, and the change in stress was calculated in the same way as in step 1. Note that in the process of step 2, the floor slab enters a shrinkage process, and in step 3, both the floor slab and the pre-casting of the wall parapet enter a shrinkage process. Therefore, it is expected that the accuracy of the calculation can be improved by considering the shrinkage of the concrete that was cast earlier. However, in this trial calculation, since the period of this process is short, it was assumed that the effect of shrinkage could be ignored, and it was omitted for simplification. The stress shown in step 3 of Figure 17 is the stress just before the transition to the contraction process.

[0158] ((3) Stress during contraction) The concrete in the floor slab and wall parapet, which is cast first and then second, undergoes different shrinkage strain changes during the shrinkage process. Therefore, it is necessary to appropriately evaluate the shrinkage behavior of the concrete in each member as a unit strain to be used in iterative calculations. The shrinkage strain of the second-cast concrete, which is the final lift, is 100 × 10⁻⁶. -6 The proportion of shrinkage strain in the pre-cast concrete and the floor slab was evaluated as follows:

[0159] The upper part of Figure 18 shows the shrinkage strain of each member used in the method according to one embodiment of this disclosure. The middle part converts this shrinkage strain to a daily change, and the lower part further organizes it as a ratio to the post-casting of the wall parapet, which is the final lift. The ratio of the change in shrinkage strain of each member differs depending on the age of the material, but using the period from the start of drying as a factor, the average value over that period is used as a representative value, and the data is summarized in Figure 19 for three levels: 1 year, 3 years, and 10 years from the start of drying. When the average period is short, as in the middle part of Figure 18, the change in shrinkage of the floor slab, which has a large volume-to-surface area ratio, is smaller than that of the wall parapet, and the ratio of shrinkage strain to post-casting shown in Figure 19 is also smaller for the floor slab. Subsequently, as the average period lengthens, the change in shrinkage strain of the wall parapet approaches the value of the floor slab, and the ratio of shrinkage strain to post-casting shown in Figure 19 becomes larger. Figures 17 and 18 illustrate the case where the average period is 3 years.

[0160] ((4) Prediction of crack occurrence) From the calculation results of the stress generated during the casting process and the stress corresponding to the unit strain generated during the shrinkage process, as shown in Figure 20, the shrinkage strain (E in Figure 17) at which the stress reaches the tensile strength is determined, and by substituting this into the shrinkage strain calculation formula in Appendix 1 (4), the age at which the strain reaches this tensile strength is calculated in reverse, which is the age at which cracking occurs (F in Figure 17).

[0161] When focusing on the wall railing, the age at which the generated stress exceeds the tensile strength is the expansion of specimen I. The average lifespan for pre-cast concrete was 13.1 years, while that of post-cast ordinary concrete was 2.5 years. In specimen II, which used expansive concrete, the average lifespan for pre-cast concrete was over 20 years, while that of post-cast concrete was 14.9 years.

[0162] ((5) Comparison of the method relating to one aspect of this disclosure with the simplified method) Figure 21 shows the lower edges of the pre-incised and post-incised sections of specimens I and II as representative examples in this disclosure. This section compares the stress levels of one embodiment of the method with those of the simplified method. The shrinkage strain applied as unit strain in the simplified method was set to the three levels shown in Figure 19. Tensile stress is also indicated.

[0163] As shown in the figure, in the simplified method where the calculation range for shrinkage strain is set to 1 year, both specimens I and II showed The stress generated by shrinkage was excessive compared to the method according to one aspect of this disclosure. When the calculation range was set to 3 years, the result was almost in agreement with the method according to one aspect of this disclosure, and was a conservative evaluation with slightly higher stress. From this result, we believe that there is no major problem with assuming that the Young's modulus of the concrete during the shrinkage process is constant. On the other hand, when the calculation range was set to 10 years, the generated stress was insufficient compared to the method according to one aspect of this disclosure. A similar trend was obtained at other evaluation points.

[0164] In this case, the amount of shrinkage of the floor slab that restrains the wall parapet is large when the calculation range for shrinkage strain is long, and conversely, small when it is short. Therefore, when the calculation range is short, the stress generated because the floor slab, which shrinks less, restrains the shrinkage of the wall parapet becomes large. Conversely, when the calculation range is long, the shrinkage of the floor slab approaches that of the wall parapet, so the degree of restraint becomes smaller compared to when the calculation range is short, indicating that the generated stress is gentler.

[0165] Thus, it was shown that when applying the simplified method, the resulting stress can be evaluated by appropriately determining the degree of shrinkage of the constrained deck slab. On the other hand, it was shown that if the shrinkage of the deck slab is underestimated, the resulting stress will be large, and this will significantly affect the calculation of the age at which the tensile strength is expected to be exceeded.

[0166] This case, and others, demonstrates the importance of properly evaluating the shrinkage of the concrete in the restraining body that constrains the volume change of the concrete member being evaluated, as this significantly affects the resulting stress. It is crucial to recognize that ignoring the shrinkage of the deck slab, even on the safe side, can lead to excessive stress.

[0167] [5. Summary] We further extended the estimation method for CPC members without a symmetric axis using a layered model and proposed a method to estimate the stress and strain distribution that occurs in the cross-section over the long term, using volume changes such as drying shrinkage due to the subsequent aging as input values. We examined the proposed method by reproducing a cross-section without a symmetric axis during the construction process, such as when casting wall parapets one side at a time, and by comparing it with experimental results in which the volume changes of each member were varied using expansive concrete. The following findings were obtained.

[0168] (1) The calculated values ​​obtained by the method according to one aspect of this disclosure showed that, similar to experimental values, a strain distribution corresponding to the asymmetry was obtained in the height and width directions of the cross-section, and that the strain behavior during the subsequent shrinkage process could be reproduced globally.

[0169] (2) Using a method according to one aspect of the present disclosure, the stress distribution of the cross-section was estimated, and it became clear that the effect of expansive concrete and the stress generated by contraction are determined by the relationship between the target member and the member that restrains it, and that there are areas where stress is locally concentrated in the restraining member that acts as a reaction force. It is desirable to appropriately evaluate and control these relationships.

[0170] (3) To further simplify the method according to one aspect of the present disclosure, we proposed a method using unit strain, assuming that the Young's modulus of concrete is constant during the shrinkage process. When the restraining body is concrete, the restraining body itself shrinks, which changes the degree of restraint on the target member and has been shown to have a significant impact on the evaluation of the generated stress. It is also necessary to appropriately evaluate the shrinkage of the concrete of the restraining body that restrains the volume change of the concrete member to be evaluated.

[0171] [6. Appendix 1: Analysis Conditions Part 1 - Physical Properties] ((1) Compressive strength) The compressive strength used in the analysis is from the JSCE Design Specifications. 7) The formula 12, as described in Section 5.1 (pp. 343-344) of Chapter 6, was used. Note that the constants a, b, and s in the compressive strength expression formula are used. f The identification values ​​used were approximated by the least squares method based on experimental values ​​from a φ100mm × 200mm test piece that underwent the same curing process as the specimen.

[0172]

number

[0173] Here, f' c (t): Compressive strength of concrete at effective age t days (N / mm²) 2 ), f' c : Compressive strength of concrete at controlled age (28 days old) (N / mm²) 2 ), a, b: constants corresponding to the type of cement and standard age, s f : The effective age corresponding to the hardening origin depending on the type of cement was uniformly set to 0.37 days in this calculation, based on a comprehensive judgment of the point of rapid strain increase and the results of visual judgment of the end of setting in experimental data.

[0174] ((2) Tensile strength) The tensile strength is a function of the compressive strength, according to the JSCE Design Specifications. 7) Based on Section 6, Chapter 5.1 (p. 343), the following formula was established.

[0175]

number

[0176] Here, f t (t): Tensile strength at age t day (N / mm²) 2 ), c1 and c2: Identification values ​​obtained by approximating experimental values ​​using the least squares method were used.

[0177] ((3) Young's modulus) The Young's modulus of the concrete used in the analysis is from the JSCE Design Specifications. 7) Formula 14 was used, with reference to Section 5.1.2 (pp. 345-346) of Part 6. The constants A and B in the formula were approximated using the least squares method based on experimental values ​​from a φ100mm × 200mm test piece cured under the same conditions as the specimen. Furthermore, the creep reduction coefficient φ was determined from the JSCE Specifications Design Edition. 7) So, the effective age until the maximum temperature is reached is 0.42, the effective age + 1 day after the maximum temperature is reached is 0.65, and the period in between is linearly interpolated. However, since this time mass concrete is not the subject, we will refer to the 2002 Standard Specifications for Concrete [Construction Edition]. 8) Based on this, "effective age at which the maximum temperature is reached" was reinterpreted as "3 days of age." That is, the period up to 3 days of age was set to 0.42, the period from 4 days of age onward to 0.65, and linear interpolation was used in between.

[0178]

number

[0179] ((4) Contraction strain) The calculation of shrinkage is based on the JSCE Specifications Design Edition. 7), the number 15 expressed by the superposition of the functions representing the time-dependent change in the drying shrinkage strain of concrete and the time-dependent change in shrinkage under sealed conditions described in Section 3.3.3.2 (pp. 252-256) of Chapter 4 was used. The first term on the right side is positioned as the strain due to drying shrinkage, and the second term is positioned as the shrinkage strain (strain due to autogenous shrinkage) under the sealed state.

[0180]

Number

[0181] Here, : the shrinkage strain of concrete (×10 -6 ) at the age of t days, : the strain due to drying shrinkage of concrete (×10 -6 ) at the age of t days, : the shrinkage strain of concrete under sealed conditions (×10 -6 ) at the age of t days. Note that in the Design Section of the JSCE Standard Specifications 7) , Chapter 6 Inspection of Thermal Cracking 4.2 Consideration of Autogenous Shrinkage (pp. 339-341), although the calculation formula for autogenous shrinkage strain is described in a similar format, considering that there is no calculation formula for drying shrinkage, the calculation formula in Chapter 4 was adopted.

[0182] ≪(a) Strain due to drying shrinkage≫ The strain due to drying shrinkage of concrete at the age of t days was calculated by Equation 16.

[0183]

Number

[0184]

Number

Number

Number

[0185] Here, V / S is the volume surface area ratio (mm) of the concrete to be targeted, V is the volume (mm 3 ) of the concrete to be targeted, and S is the surface area (mm 2 ) of the dry surface of the concrete to be targeted.

[0186] Also, it is the final value (×10 -6 ) of the shrinkage strain due to dry shrinkage in the case of a 100×100×400 mm prism and is calculated from Equation 20.

[0187]

Equation

[0188] Here, W / C is the water-cement ratio (%) (35 ≤ W / C ≤ 65%), RH is the relative humidity (%) (50 ≤ RH ≤ 80%), t is the age (days) of the concrete, t0 is the initial age (days) of the concrete at the start of drying, α ds , β ds : are coefficients representing the progress characteristics of the dry shrinkage strain and are calculated from Equation 21 and Equation 22.

[0189]

Equation

[0190]

Equation

[0191] ≪(b) Shrinkage Strain under Sealed Conditions≫ Equation 23 was used to calculate the shrinkage strain under sealed conditions at the age of t days.

[0192]

Equation

[0193]

Equation

Equation

Equation

[0194] Also, is the final value of shrinkage strain (×10 -6 ) under the sealing condition for a 100×100×400 mm square prism, calculated from Equation 27.

[0195]

Equation

[0196] Here, α as , β as : Coefficients representing the progress of shrinkage under the sealing condition, obtained from Equation 28 and Equation 29.

[0197]

Equation

Equation

[0198] ((5) Expansion Strain) Expansion strain ε ex was formulated by the following equation, referring to the Crack Control Guidelines for Mass Concrete 2016 9) .

[0199]

Equation

[0200] Here, ε ex ∞ (×10 -6 ): The ultimate value of expansion strain. In this calculation, the expansion coefficient of the uniaxially restrained expansion test shown in Figure 13 of JIS A6202 was adopted. α and β: Coefficients related to the occurrence of expansion strain, as defined in the Guidelines for Cracking Control of Mass Concrete 2016. 9) Based on this, the formula was formulated with α=0.9 and β=1.0. Note that t0 is s in the calculation of compressive strength. f It was set to the same value as [the other value].

[0201] Figure 22 shows a list of input conditions for the analysis. Figure 23 is a diagram illustrating these input conditions.

[0202] [7. Appendix 2 Analysis Conditions Part 2 Calculation Conditions] ((1) Timetable) The age of the concrete slabs used in the analysis was the same as the experimental values, as shown in Figure 24. For calculation purposes, the concrete slab placement was consistently set to day 0.

[0203] ((2) Scope of application of the constitutive rules) Figure 25 summarizes the age of the material and the applicable constitutive law. In specimen I, the floor slab had an expansion coefficient of 0 × 10⁻⁶ according to JIS A6202. -6 For ordinary concrete, the work U up to age 7 was treated as zero, applying the assumption of constant work rate. Also, for ordinary concrete cast after wall parapet, the expansion rate was -10 × 10 -6 Therefore, in calculating strain under the assumption of constant work rate, it was treated as negative (expansion on the contraction side). On the other hand, in specimen II to which expansive concrete was applied, the conventional assumption of constant work rate was applied in all cases.

[0204] <References> The matters described herein may be understood in relation to the following references. 1) Tsuji, Yukikazu: Estimation method for chemical prestress and expansion distribution, Concrete Engineering, Vol. 19, No. 6, pp. 99-105, 1981.6 2) Kentaro Suhara, Chunhak Li, Kiminobu Ashida, Yukikazu Tsuji: Evaluation of bending crack width of CPC beams using expansive concrete, Annual Proceedings of the Concrete Engineering Society, Vol.31, No.2, pp.229-234, 2009. 3) Iso Kanzu, Junichi Kimura: Management of crack resistance of composite bridge decks by quantitative analysis of chemical prestress, Proceedings of the 9th Symposium on Road Bridge Decks, pp. 47-52, 2016. 4) Li Chun-hak, Tsuji Yukikazu, Suhara Kentaro: Mechanical properties of CPC beams and RC beams with different reinforcement arrangements, Proceedings of the 28th Symposium of the Japan Society of Prestressed Concrete Engineering, pp. 741-746, 2019.11 5) Kentaro Suhara, Yukikazu Tsuji, Chunhak Li, Tatsuya Nishizaki, Kazuma Igarashi, Mineiso Kando: Estimation method for expansion strain distribution of CPC members without a symmetry axis using expansive concrete, Journal of Japan Society of Civil Engineers, Series E2 (Materials and Concrete Structures), Vol.77, No.2, pp.25-36, 2021. 6) Mineiso Kando, Takumi Maeda, Kazuma Igarashi, Kentaro Suhara, Chunhak Li, Yukikazu Tsuji: Expansion and contraction behavior of expansive concrete used in full-scale road bridge deck slabs and wall parapet specimens, Journal of Japan Society of Civil Engineers, Series E2 (Materials and Concrete Structures), Vol.78, No.1, pp.62-71, 2022. 7) Japan Society of Civil Engineers: Standard Specifications for Concrete [Design Edition], 2022, 2023. 8) Japan Society of Civil Engineers: Standard Specifications for Concrete [Construction Section], 2002, Chapter 4: Crack Checking during Construction, pp. 41-54, 2002. 9) Japan Concrete Institute: Guidelines for Cracking Control of Mass Concrete 2016, Reference Material 11: Design Values ​​for Expansion Strain, pp. 197-202, 2016.

[0205] The embodiments described above are provided to facilitate understanding of this disclosure and are not intended to limit it. The elements of the embodiments, as well as their arrangement, materials, conditions, shapes, and sizes, are not limited to those exemplified and can be modified as appropriate. Furthermore, configurations shown in different embodiments can be partially substituted or combined.

[0206] <Embodiments of this Disclosure> This disclosure includes the following embodiments.

[0207] (Note 1) Information processing device 2 includes an estimation unit 102 that estimates at least one of the strain distribution and stress distribution in a cross-section of a concrete structure whose volume change is constrained by a restraining body and which has a cross-section without an axis of symmetry, based on the age of the members used in the concrete structure and / or the amount of shrinkage over time due to the free strain of the concrete structure.

[0208] (Note 2) The information processing device 2 as described in Appendix 1, wherein the estimation unit 102 estimates at least one of the strain distribution and stress distribution of the cross-section at a third time point, based on the increment of stress occurring in the cross-section during the period from the first time point to the second time point, and the increment of stress occurring in the cross-section during the period from the second time point to the third time point.

[0209] (Note 3) The information processing device 2 according to Appendix 1 or 2, further comprising: a determination unit 104 that, when the estimation unit 102 estimates the stress distribution in the cross-section, determines whether the tensile force acting on at least a portion of the cross-section exceeds a predetermined threshold based on the said stress distribution.

[0210] (Note 4) The information processing device 2 as described in Appendix 3 further comprises an output unit 108 that outputs suggested information regarding parameters for designing a concrete structure when the determination unit 104 determines that the tensile force acting on at least a portion of the cross-section exceeds a predetermined threshold.

[0211] (Note 5) The proposed information includes information about expansive materials to be added when producing concrete structures, as described in Appendix 4, for the information processing device 2.

[0212] (Note 6) The information processing device 2 described in Appendix 5 determines information regarding the expansive material to be added to the concrete structure based on at least the estimated stress distribution of the concrete structure assuming a first amount of expansive material is added, and the estimated stress distribution of the concrete structure assuming a second amount of expansive material is added.

[0213] (Note 7) The concrete structure includes, along the direction of the cross-section, an existing structure, a first concrete body poured into the existing structure, and a second concrete body poured into the first concrete body, and the information relating to the expansive material to be added to the concrete structure includes information relating to the expansive material to be added when producing the first concrete body and the second concrete body, respectively, as described in Appendix 5 or 6 of the information processing device 2.

[0214] (Note 8) The information processing device 2 according to any one of the appendices 1 to 7 further comprises an acquisition unit 100 for acquiring information regarding the age of a component or the amount of shrinkage over time.

[0215] (Note 9) The concrete structure includes, along the direction of the cross-section, an existing structure, a first concrete body poured into the existing structure, and a second concrete body poured into the first concrete body, and the estimation unit 102 estimates at least one of the strain distribution and stress distribution in the cross-section of the concrete structure, assuming that the first concrete body is of a first age and the second concrete body is of a second age different from the first age, the information processing device 2 according to any one of appendices 1 to 8.

[0216] (Note 10) The information processing device 2 according to any one of Appendix 1 to 9, wherein the estimation unit 102 estimates at least one of the strain distribution and stress distribution in the cross-section of a concrete structure at a given age by multiplying the amount of change per unit period of at least one of the strain distribution and stress distribution in the cross-section of the concrete structure by a predetermined coefficient.

[0217] (Note 11) The information processing device 2 according to any one of Appendix 1 to 10, wherein the estimation unit 102 estimates at least one of the strain distribution and stress distribution in the cross-section of a concrete structure by multiplying the change amount per unit shrinkage of the concrete structure by a predetermined coefficient.

[0218] (Note 12) A design support device for assisting in the design of a concrete structure in which volume change is constrained by a restraining body and which has a cross-section without an axis of symmetry, comprising an estimation unit 102 that estimates at least one of the strain distribution and stress distribution in the cross-section of the concrete structure based on the age of the members used in the concrete structure and / or the amount of shrinkage over time due to the free strain of the concrete structure.

[0219] (Note 13) An information processing method that causes at least one processor 700 to estimate at least one of the strain distribution and stress distribution in a cross-section of a concrete structure whose volume change is constrained by a constraint body and which has a cross-section without an axis of symmetry, based on the age of the members used in the concrete structure and / or the amount of shrinkage over time due to the free strain of the concrete structure.

[0220] (Note 14) A program that causes at least one processor 700 to estimate at least one of the strain distribution and stress distribution in a cross-section of a concrete structure whose volume change is constrained by a constraint and which has no axis of symmetry, based on the age of the members used in the concrete structure and / or the amount of shrinkage over time due to the free strain of the concrete structure. [Explanation of symbols]

[0221] 1...System, 2...Information processing device, 3...Terminal device, 4...Communication network, 10...Control unit, 12...Storage unit, 14...Network interface unit, 70...Computer, 100...Acquisition unit, 102...Estimation unit, 104...Determination unit, 106...Decision unit, 108...Output unit, 700...Processor, 702...Storage device, 710...Display device

Claims

1. An information processing device comprising an estimation unit that estimates at least one of the strain distribution and stress distribution in a cross-section of a concrete structure whose volume change is constrained by a restraining body and which has a cross-section without an axis of symmetry, based on the age of the members used in the concrete structure and / or the amount of shrinkage over time due to the free strain of the concrete structure.

2. The information processing apparatus according to claim 1, wherein the estimation unit estimates at least one of the strain distribution and stress distribution of the cross-section at the third time point, based on at least the increment of stress occurring in the cross-section during the period from the first time point to the second time point, and the increment of stress occurring in the cross-section during the period from the second time point to the third time point.

3. The information processing apparatus according to claim 1, further comprising: a determination unit that, when the estimation unit estimates the stress distribution in the cross-section, determines whether the tensile force acting on at least a portion of the cross-section exceeds a predetermined threshold based on the said stress distribution.

4. The information processing apparatus according to claim 3, further comprising: an output unit that outputs suggested information regarding parameters for designing the concrete structure when the determination unit determines that the tensile force acting on at least a portion of the cross-section exceeds a predetermined threshold;

5. The information processing apparatus according to claim 4, wherein the proposed information includes information regarding an expansive material to be added when producing the concrete structure.

6. The information processing device according to claim 5, wherein the information regarding the expansive material to be added to the concrete structure is determined based on at least the estimated stress distribution of the concrete structure assuming that a first amount of expansive material is added, and the estimated stress distribution of the concrete structure assuming that a second amount of expansive material is added.

7. The concrete structure includes, along the direction of the cross-section, an existing structure, a first concrete body poured into the existing structure, and a second concrete body poured into the first concrete body. The information processing apparatus according to claim 5, wherein the information relating to the expansive material to be added to the concrete structure includes information relating to the expansive material to be added when producing the first concrete body and the second concrete body, respectively.

8. The information processing apparatus according to claim 1, further comprising an acquisition unit for acquiring information regarding the age of the member or the amount of shrinkage over time.

9. The concrete structure includes, along the direction of the cross-section, an existing structure, a first concrete body poured into the existing structure, and a second concrete body poured into the first concrete body. The information processing device according to claim 1, wherein the estimation unit estimates at least one of the strain distribution and stress distribution in the cross-section of the concrete structure, assuming that the first concrete body is at a first age and the second concrete body is at a second age different from the first age.

10. The information processing apparatus according to claim 1, wherein the estimation unit estimates at least one of the strain distribution and stress distribution in the cross-section of the concrete structure at the age of the member by multiplying the amount of change per unit period of at least one of the strain distribution and stress distribution in the cross-section of the concrete structure by a predetermined coefficient.

11. The information processing apparatus according to claim 1, wherein the estimation unit estimates at least one of the strain distribution and stress distribution in the cross-section of the concrete structure at a given time shrinkage by multiplying the change in the amount of change per unit shrinkage of the concrete structure by a predetermined coefficient.

12. A design support device for assisting in the design of concrete structures whose volume change is constrained by a restraining body and which have a cross-section without an axis of symmetry, A design support device comprising an estimation unit that estimates at least one of the strain distribution and stress distribution in the cross-section of the concrete structure based on the age of the members used in the concrete structure and / or the amount of shrinkage over time due to free strain of the concrete structure.

13. At least one processor, An information processing method for estimating at least one of the strain distribution and stress distribution in a cross-section of a concrete structure whose volume change is constrained by a restraining body and which has a cross-section without an axis of symmetry, based on the age of the members used in the concrete structure and / or the amount of shrinkage over time due to the free strain of the concrete structure.

14. At least one processor, A program that causes a concrete structure having a cross-section in which volume change is constrained by a restraining body and which has no axis of symmetry, to estimate at least one of the strain distribution and stress distribution in the cross-section, based on the age of the members used in the concrete structure and / or the amount of shrinkage over time due to free strain of the concrete structure.

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