JP7598560B2 - Lateral pressure test device, formwork, and lateral pressure measurement method - Google Patents

Description

The present invention relates to a lateral pressure test device, a formwork used in the lateral pressure test device, and a lateral pressure measurement method using the lateral pressure test device.

When fresh concrete is poured into a formwork, pressure (lateral pressure) from the fresh concrete acts on the formwork. If the formwork is not designed taking this lateral pressure into account, the formwork may deform or break during pouring, which may lead to an accident in which the fresh concrete spills out. In particular, in recent years, research has been conducted into concrete with increased fluidity from the perspective of improving productivity, but this type of concrete tends to generate greater lateral pressure.

Conventionally, the method of calculating lateral pressure is to treat fresh concrete as a liquid and calculate the lateral pressure as liquid pressure (liquid density x gravitational acceleration x depth). Since the liquid pressure is greater than the actual lateral pressure, a formwork designed based on the lateral pressure calculated in this way is the safest as it is less likely to deform or break, but the cost of the formwork increases due to unnecessary reinforcement. Therefore, the lateral pressure is measured in advance in a preliminary experiment (hereinafter referred to as a lateral pressure test), and the formwork is designed based on the results. For example, Non-Patent Document 1 discloses a method of assembling a full-scale formwork, pouring fresh concrete in a manner simulating actual construction, and measuring the lateral pressure.

Toru Kawai, Yasuhiro Kuroda, Yoshihiro Takekawa, "Experimental Study on the Properties of High-Fluidity Concrete Using Low-Heat Cement", Proceedings of the Japan Society of Civil Engineers, Japan Society of Civil Engineers, No. 462/VI-18, pp. 111-120, 1993

However, when constructing formwork to simulate actual construction as in Non-Patent Document 1, the height of the formwork will be large for components with a large cast-in height that will increase lateral pressure. Such formwork requires large-scale assembly, which not only requires time and effort to prepare, but also requires equipment such as hoppers and cranes to pour the fresh concrete from the top. In addition, if a large amount of fresh concrete is to be poured, it takes time and effort to prepare and manufacture the materials for the fresh concrete.

The present invention was made in consideration of these circumstances, and aims to provide a lateral pressure test device, formwork, and lateral pressure measurement method that can improve the work efficiency of lateral pressure tests.

The lateral pressure test device according to the present invention is a lateral pressure test device for measuring the lateral pressure acting on a formwork from fresh concrete, and is provided with a formwork consisting of a bottom plate and a cylindrical side wall portion erected above the bottom plate and forming an internal space, at least one weight configured to be accommodated in the internal space and having a density greater than that of the fresh concrete, and at least one pressure gauge arranged on the side wall portion for measuring the lateral pressure acting on the formwork from the fresh concrete, the side wall portion having a first region formed to be able to accommodate the fresh concrete in the internal space, and a second region formed continuously above the first region and configured to be able to accommodate the weight in the internal space, the second region having a side wall opening portion that opens the internal space to the side, and configured so that the fresh concrete and the weight can be poured into the internal space from the side wall opening portion.

The lateral pressure test device includes a second area above the first area in which fresh concrete is contained, in which a weight having a density greater than that of the fresh concrete is contained, so that the height of the entire formwork can be made lower than when only fresh concrete is contained in the internal space. By making the formwork smaller in size in this way, the time and labor required for assembling the formwork can be reduced. In addition, the amount of fresh concrete poured can be reduced, so that the time and labor required for preparing and manufacturing the materials for the fresh concrete can be reduced. Furthermore, the second area includes a side wall opening that opens the internal space to the side, and is configured so that the fresh concrete and the weight can be poured into the internal space from the side wall opening, so that it is no longer necessary to pour the fresh concrete and the weight from the top of the formwork, and equipment such as a hopper or a crane is not required. As a result, the work efficiency of the lateral pressure test can be improved.

The side pressure test device according to the present invention may further include a shutter material that closes the side wall opening.

The side pressure test device is configured in this way to prevent the weight housed in the internal space from falling from the side wall opening to the outside of the side wall.

The lateral pressure test device according to the present invention may be configured such that the pressure gauge is positioned at a distance of 10 cm to 30 cm above the bottom plate portion.

This configuration of the lateral pressure test device makes it less susceptible to the effects of friction between the bottom plate and fresh concrete, allowing for more accurate measurement of lateral pressure.

The formwork according to the present invention is a formwork used in a lateral pressure test device, and is composed of a bottom plate portion and a cylindrical side wall portion erected above the bottom plate portion and forming an internal space, the side wall portion having a first region formed so that fresh concrete can be accommodated in the internal space, and a second region formed continuously above the first region and so that a weight can be accommodated in the internal space, the second region having a side wall opening portion that opens the internal space to the side.

The formwork has a side wall opening in the second area that opens the internal space to the side, and is configured so that fresh concrete and a weight can be poured into the internal space from the side wall opening, eliminating the need to pour the fresh concrete and the weight from the top of the formwork and eliminating the need for equipment such as a hopper or a crane. As a result, the work efficiency of the lateral pressure test can be improved.

The lateral pressure measurement method according to the present invention is a lateral pressure measurement method that uses the above-mentioned lateral pressure test device to measure the lateral pressure acting on the formwork from the fresh concrete, and includes a pouring step in which the fresh concrete is poured into the internal space of the formwork from the side wall opening and poured at least to a height that covers the pressure gauge, a loading step in which, after the pouring step, the weight is poured into the internal space of the formwork from the side wall opening and loaded onto the fresh concrete, and a lateral pressure measurement step in which, in parallel with the pouring step and the loading step, the pressure gauge is used to measure the lateral pressure acting on the formwork from the fresh concrete.

The lateral pressure measurement method eliminates the need to pour the fresh concrete and the weight into the internal space from the side wall opening, eliminating the need to pour the fresh concrete and the weight from the top of the formwork, and eliminates the need for equipment such as a hopper or a crane. In addition, by loading a weight having a density greater than that of the fresh concrete onto the fresh concrete, the overall height of the formwork can be made lower than when only fresh concrete is placed in the internal space. By making the formwork smaller in this way, the time and labor required to assemble the formwork can be reduced. In addition, since the amount of fresh concrete poured can be reduced, the time and labor required to prepare and manufacture the materials for the fresh concrete can be reduced. As a result, the work efficiency of the lateral pressure test can be improved.

The lateral pressure measurement method according to the present invention may employ a pouring method in which the fresh concrete is poured in layers during the pouring process.

The above-mentioned lateral pressure measurement method, with its configuration, makes it possible to measure lateral pressure using the driving method used in actual construction work, allowing for more accurate lateral pressure measurements.

The present invention provides a lateral pressure test device, formwork, and lateral pressure measurement method that can improve the work efficiency of lateral pressure tests.

FIG. 1 is a perspective view of a lateral pressure testing device 1 according to one embodiment of the present invention. FIG. 2 is a front view showing a state in which the lateral pressure testing device 1 according to one embodiment of the present invention is in use. FIG. 3 is a cross-sectional view showing the lateral pressure test device 1 of FIG. 2 taken along line III-III. FIG. 4 is a graph showing the results of measuring the lateral pressure using the lateral pressure test device 1 of FIG.

The lateral pressure test device 1, formwork 2, and lateral pressure measurement method according to this embodiment will be described below with reference to the drawings. Note that the same or corresponding parts in the following drawings are given the same reference numerals, and their description will not be repeated.

<Lateral pressure test device and formwork>
The lateral pressure test device 1 and the formwork 2 according to this embodiment will be described below. FIG. 1 is a perspective view of the lateral pressure test device 1 according to one embodiment of the present invention. FIG. 2 is a front view showing the lateral pressure test device 1 according to one embodiment of the present invention in use. FIG. 3 is a cross-sectional view showing the III-III cross section of the lateral pressure test device 1 of FIG. 2. As shown in FIG. 1, the lateral pressure test device 1 according to this embodiment includes a formwork 2 composed of a bottom plate portion 21 and a side wall portion 22, a weight 3 configured to be able to be accommodated in the internal space R of the formwork 2, and a pressure gauge 4 arranged on the side wall portion 22 of the formwork 2.

First, the formwork 2 will be described. The formwork 2 according to this embodiment is composed of a bottom plate portion 21 and a cylindrical side wall portion 22 that stands above the bottom plate portion 21 and forms an internal space R. That is, the side wall portion 22 is disposed so as to extend in the vertical direction (Z direction in FIG. 2), and the bottom plate portion 21 is provided below the side wall portion 22.

The bottom plate portion 21 is formed in a flat plate shape that is rectangular when viewed from above. When viewed from above, the bottom plate portion 21 has an extension portion 21a that extends outward from the position where the side wall portion 22 is erected. A reinforcing material 7 (described later) can be attached to the extension portion 21a. Note that when viewed from above, the state is that viewed from above in the vertical direction (Z direction in FIG. 2).

A pedestal 6 is provided below the bottom plate portion 21. The pedestal 6 is fixed to the bottom plate portion 21 by fixing members such as bolts and nuts. The pedestal 6 has a fork insertion portion 61 in which a space is formed into which the forks of a forklift, such as a pallet, can be inserted. As the pedestal 6 has the fork insertion portion 61, the formwork 2 can be easily moved with a forklift or hand lift even after it has been assembled, and the work efficiency of the lateral pressure test can be further improved.

The side wall portion 22 is composed of four side plates 23. Specifically, the four side plates 23 are connected by fixing members 24 to form a cylindrical shape that is rectangular when viewed from above. The lower end of the side wall portion 22 is fixed to the bottom plate portion 21 by the fixing members 24, forming an internal space R that is open at the top.

The side wall portion 22 includes a first region 22a formed so that fresh concrete can be accommodated in the internal space R, and a second region 22b formed continuously above the first region 22a and so that a weight 3 (described later) can be accommodated in the internal space R. The first region 22a is composed of four side panels 23 and is formed into a cylindrical shape that is rectangular when viewed from above. This allows the first region 22a to accommodate fresh concrete in the internal space R.

The second area 22b is composed of three side plates 23 and has a side wall opening 25 that opens the internal space R to the side. Specifically, the second area 22b is composed of three of the four side plates 23 that make up the first area 22a, which extend continuously upward, and one side plate 23 is not placed, forming the side wall opening 25. That is, the side wall 22 is composed of three side plates 23 that are equal in height from the bottom plate 21 and one side plate 23 that is lower in height than the three side plates 23, forming the side wall opening 25 in the second area 22b. As a result, the second area 22b can accommodate a weight 3 (described later) in the internal space R, and fresh concrete and weight 3 can be poured into the internal space R from the side wall opening 25.

Next, the weight 3 will be described. The weight 3 has a density greater than that of fresh concrete. Examples of materials for the weight 3 include steel, bronze, and brass. The weight 3 is composed of multiple flat weights 31, from the viewpoint of reducing the burden on the worker who moves the weight 3 and efficiently inserting the weight 3. The thickness of the flat weights 31 can be changed as appropriate.

The flat weights 31 are formed in a rectangular shape when viewed from above, so as to apply weight uniformly to the fresh concrete, and are placed in layers when inserted into the internal space R from the side wall opening 25 with their thickness direction oriented in the vertical direction (Z direction in FIG. 1). In order to reliably apply weight to the fresh concrete, the flat weights 31 placed in the internal space R are preferably placed 1.5 mm to 2.5 mm away from the inner wall of the side wall 22 when viewed from above. In other words, the size of the flat weights 31 when viewed from above is smaller than the size of the rectangular shape formed by the inner wall of the side wall 22.

Next, the pressure gauge 4 will be described. The pressure gauge 4 is disposed on the side wall portion 22, and measures the lateral pressure acting on the formwork 2 from the fresh concrete. More specifically, the pressure gauge 4 is disposed in the first region 22a of the side wall portion 22. In order to make the pressure gauge 4 less susceptible to the effects of friction between the bottom plate portion 21 and the fresh concrete and to measure the lateral pressure more accurately, it is preferable that the pressure gauge 4 is disposed at a distance of 10 cm to 30 cm above the bottom plate portion 21. There are no particular limitations on the type of pressure gauge 4, and for example, a conventionally known pressure gauge such as an earth pressure gauge can be used.

The lateral pressure test device 1 is equipped with a shutter material 5 configured to be able to close the side wall opening 25. The shutter material 5 is composed of multiple flat plate members 51. The flat plate members 51 are rectangular in shape with a longitudinal direction and a width direction in a plan view, and are attached to the formwork 2 with the width direction being the vertical direction (Z direction in FIG. 2). Specifically, the formwork 2 has guide parts 26 that form grooves at a pair of ends extending along the vertical direction of the side wall opening 25, and the multiple flat plate members 51 are inserted from above toward below along the grooves of the guide parts 26. This makes it possible to close the side wall opening 25.

The lateral pressure test device 1 is provided with a reinforcing member 7 that supports the formwork 2 from the viewpoint of preventing the formwork 2 from falling over. The reinforcing member 7 extends in the vertical direction along the side surface of the sidewall portion 22 and is fixed to the sidewall portion 22; a bottom plate fixing portion 72, one end of which is connected to the lower end of the sidewall fixing portion 71, extends in a planar direction (direction along the XY plane in FIG. 1) along the upper surface of the bottom plate portion 21 and is fixed to the bottom plate portion 21; and a reinforcing portion 73 that connects the upper end of the sidewall fixing portion 71 and the other end of the bottom plate fixing portion 72. That is, the reinforcing member 7 has a right-angled triangular shape in a side view due to the sidewall fixing portion 71, the bottom plate fixing portion 72, and the reinforcing portion 73. It is preferable that the reinforcing member 7 is disposed at each of the four corners of the sidewall portion 22 from the viewpoint of further improving safety.

The lateral pressure test device 1 according to this embodiment is provided with a second region 22b above the first region 22a in which fresh concrete is contained, in which a weight 3 having a density greater than that of fresh concrete is contained, so that the overall height of the formwork 2 can be made lower than when only fresh concrete is contained in the internal space R. By making the formwork 2 smaller in size in this way, the time and labor required for assembling the formwork 2 can be reduced. In addition, since the amount of fresh concrete poured can be reduced, the time and labor required for preparing and manufacturing the materials for fresh concrete can be reduced. Furthermore, the second region 22b is provided with a side wall opening portion 25 that opens the internal space R to the side, and is configured so that fresh concrete and weight 3 can be poured into the internal space R from the side wall opening portion 25, so that it is no longer necessary to pour the fresh concrete and weight 3 from the top of the formwork 2, and equipment such as a hopper and a crane are not required. As a result, the work efficiency of the lateral pressure test can be improved.

The side pressure testing device 1 according to this embodiment further includes a shutter material 5 that closes the side wall opening 25, thereby preventing the weight 3 contained in the internal space R from falling from the side wall opening 25 to the outside of the side wall 22.

The lateral pressure test device 1 according to this embodiment is able to measure lateral pressure more accurately by positioning the pressure gauge 4 at a distance of 10 cm to 30 cm above the bottom plate 21, making it less susceptible to the effects of friction between the bottom plate 21 and the fresh concrete.

In the formwork 2 according to this embodiment, the second region 22b is provided with a side wall opening 25 that opens the internal space R to the side, and is configured so that fresh concrete and weight 3 can be poured into the internal space R from the side wall opening 25. This eliminates the need to pour fresh concrete and weight 3 from the top of the formwork 2, and eliminates the need for equipment such as a hopper or crane. As a result, the work efficiency of the lateral pressure test can be improved.

<Lateral pressure measurement method>
The lateral pressure measurement method according to this embodiment is a lateral pressure measurement method that uses the above-mentioned lateral pressure test device 1 to measure the lateral pressure acting from fresh concrete to the formwork 2. The lateral pressure measurement method includes a pouring step of pouring fresh concrete from the side wall opening 25 into the internal space R of the formwork 2 to a height at least covering the pressure gauge 4, a loading step of pouring a weight 3 from the side wall opening 25 into the internal space R of the formwork 2 after the pouring step and loading the weight 3 onto the fresh concrete, and a lateral pressure measurement step of measuring the lateral pressure acting from the fresh concrete to the formwork 2 using the pressure gauge 4 in parallel with the pouring step and the loading step. Each step will be specifically described below.

In the pouring process, first, fresh concrete is poured from the side wall opening 25 into the internal space R of the formwork 2, and poured up to the lower end of the pressure gauge 4 to form the base layer 81. After a predetermined time has elapsed, fresh concrete is further poured from the side wall opening 25 into the internal space R of the formwork 2, and poured to a height that covers at least the pressure gauge 4, forming the fresh concrete layer 82. When forming the fresh concrete layer 82, it is preferable to pour the fresh concrete to a height that is 10 cm or more above the pressure gauge 4, from the viewpoint of making the fresh concrete less susceptible to the effects of friction with the weight 3 and measuring the lateral pressure more accurately. By forming the base layer 81 below the fresh concrete layer 82, the fresh concrete is less susceptible to the effects of friction between the bottom plate 21 and the fresh concrete in the fresh concrete layer 82, so that the lateral pressure can be measured more accurately.

In the pouring process, fresh concrete is poured in layers in order to measure the lateral pressure more accurately. In order to further improve the work efficiency of the lateral pressure test, it is preferable that the fresh concrete layer 82 be only one layer. Note that pouring conditions such as the pouring height of the fresh concrete and the number of layers can be changed as appropriate depending on the site conditions.

The fresh concrete is not particularly limited, and for example, any conventional fresh concrete containing cement, water, fine aggregate, and coarse aggregate can be used.

In the loading step, after a predetermined time has elapsed, a flat weight 31 is inserted from the side wall opening 25 into the internal space R of the formwork 2 and loaded onto the fresh concrete layer 82. In the lateral pressure measurement method according to this embodiment, in order to further improve the work efficiency of the lateral pressure test, in a pouring method in which fresh concrete is poured in layers, only the first layer is made of fresh concrete, and flat weights 31 are loaded on the second and subsequent layers. Each layer from the second and subsequent layers is made of ten flat weights 31. The loading of the flat weights 31 is performed on the next layer after a predetermined time interval has elapsed since the loading of one layer (loading of ten flat weights 31).

In the loading process, the shutter material 5 is installed to prevent the flat weights 31 from falling during the work. Specifically, when loading the flat weights 31, the flat members 51 are installed sequentially. The timing of installing the flat members 51 is not particularly limited, and can be, for example, the time when loading of the flat weights 31 of each layer is completed.

In the lateral pressure measurement process, the pressure gauge 4 is used to measure the lateral pressure acting on the formwork 2 from the fresh concrete. The lateral pressure measurement process is carried out in parallel with the pouring process and the loading process described above. In other words, the measurement of the lateral pressure is started at the same time as pouring the fresh concrete that constitutes the fresh concrete layer 82 after pouring the fresh concrete that constitutes the base layer 81, and ends when the loading of all the flat weights 31 has been completed. In order to perform more accurate measurements, the lateral pressure is measured using two pressure gauges 4 arranged on two adjacent faces of the four faces that constitute the side wall portion 22, and the average value of the measured lateral pressures is calculated and evaluated.

In the lateral pressure measurement method according to this embodiment, fresh concrete and weight 3 are poured into the internal space R from the side wall opening 25, so that it is not necessary to pour the fresh concrete and weight 3 from the top of the formwork 2, and equipment such as a hopper or a crane is not required. In addition, by loading weight 3 having a density greater than that of the fresh concrete on the fresh concrete, the overall height of the formwork 2 can be made lower than when only fresh concrete is contained in the internal space R. By making the formwork 2 smaller in this way, the time and labor required for assembling the formwork 2 can be reduced. In addition, since the amount of fresh concrete poured can be reduced, the time and labor required for preparing and manufacturing the materials for the fresh concrete can be reduced. As a result, the work efficiency of the lateral pressure test can be improved.

In the lateral pressure measurement method according to this embodiment, the fresh concrete is poured in layers during the pouring process, making it possible to measure lateral pressure using the pouring method used in actual construction, and thus enabling more accurate measurement of lateral pressure.

The lateral pressure test device, formwork, and lateral pressure measurement method according to the present invention are not limited to the above-mentioned embodiments, and various modifications are possible without departing from the gist of the present invention. Furthermore, it goes without saying that the configurations and methods of the above and following embodiments may be arbitrarily adopted and combined (the configurations and methods of one embodiment may be applied to the configurations and methods of other embodiments).

For example, in the above embodiment, the bottom plate portion 21 is formed in a flat plate shape that is rectangular when viewed from above. However, the present invention is not limited to this configuration, and the bottom plate portion 21 may be formed in a polygonal shape other than a rectangular shape, a circular shape, or an elliptical shape when viewed from above.

In the above embodiment, the bottom plate portion 21 has an extension portion 21a that extends outward from the side wall portion 22 when viewed from above. However, the present invention is not limited to this configuration, and the bottom plate portion 21 does not have to have the extension portion 21a. In other words, the bottom plate portion 21 and the side wall portion 22 may be the same size when viewed from above.

In the above embodiment, a pedestal 6 is provided below the bottom plate portion 21. The pedestal 6 also has a fork insertion portion 61. However, the present invention is not limited to this configuration, and the pedestal 6 does not have to be provided below the bottom plate portion 21. The pedestal 6 also does not have to have a fork insertion portion 61.

In the above embodiment, the side wall portion 22 is formed into a cylindrical shape having a square shape when viewed from above by connecting four side plates 23 with fixing members 24. However, the present invention is not limited to this configuration, and the side wall portion 22 may be formed into a cylindrical shape having a polygonal shape when viewed from above by using five or more side plates 23, or into a cylindrical shape having a triangular shape when viewed from above by using three side plates 23. The side wall portion 22 may also be formed integrally, and may be formed into a cylindrical shape having a circular shape when viewed from above by using one side plate 23, for example.

In the above embodiment, the weight 3 is composed of a plurality of flat weights 31. The flat weights 3 are formed in a rectangular shape when viewed from above. However, the present invention is not limited to this configuration, and the weights 3 may be formed as a single unit, or in a pouring method in which fresh concrete is poured in layers, the weights 3 for each layer that is loaded in layers may be formed as a single unit. The flat weights 31 may be formed in a polygonal shape other than a rectangular shape, a circular shape, or an elliptical shape when viewed from above.

In the above embodiment, the pressure gauge 4 is disposed on each of two adjacent faces of the four faces constituting the first region 22a. However, the present invention is not limited to this configuration, and the pressure gauge 4 may be disposed on each of two opposing faces of the four faces constituting the first region 22a. Furthermore, the number of pressure gauges 4 disposed may be one, or three or more.

In the above embodiment, the shutter material 5 is composed of multiple flat plate members 51. However, the present invention is not limited to this configuration, and the shutter material 5 may be formed as a single unit.

In the above embodiment, the reinforcing member 7 includes a side wall fixing portion 71, a bottom plate fixing portion 72, and a reinforcing portion 73. The reinforcing member 7 is disposed at the four corners of the side wall portion 22. However, the shape and number of the reinforcing member 7 are not particularly limited in the present invention.

The following describes examples of the present invention, but the present invention is not limited to the following examples.

<Preparation of fresh concrete>
The materials were mixed according to the ratio shown in Table 1 and mixed in a forced mixing pan mixer with a nominal capacity of 100 L (60 L/batch) to prepare fresh concrete. Specifically, cement, fine aggregate, and coarse aggregate were first dry mixed in the mixer for 15 seconds, and then water and various admixtures were added and mixed for 60 seconds. Next, after scraping, the mixture was mixed for 60 seconds to obtain fresh concrete.

Details of each component shown in Table 1 are given below.
Water (W): Tap water Cement (C): Ordinary Portland cement (manufactured by Sumitomo Osaka Cement Co., Ltd.)
Fine aggregate (S): Mountain sand (produced in Kakegawa City, Shizuoka Prefecture)
Coarse aggregate (G): Crushed stone 2005, hard sandstone (from Iwase Town, Ibaraki Prefecture)
Admixture (SP): High-performance AE water reducing agent Admixture (SR): Fluidity retaining agent Admixture (AE): AE agent

<Lateral pressure measurement>
The lateral pressure was measured on a 3.5m-high member, i.e., a seven-layer member with a fresh concrete layer height of 0.5m. The concrete was poured at a speed of 1.5m/h. The specific measurement method is explained below.

The lateral pressure was measured using the lateral pressure test device 1 in Figure 1. Specifically, the inner dimensions of the formwork 2 were set to 0.3 m x 0.3 m x 1.6 m, and the lateral pressure test device 1 was used in which two earth pressure gauges (Tokyo Measuring Instruments Laboratory, KDH-200KPA) were installed as pressure gauges 4 at a position 0.1 m above the bottom plate 21 in the side wall 22. The two earth pressure gauges were installed on two adjacent faces of the four faces that make up the side wall 22, and the average value of the lateral pressure measured by each earth pressure gauge was calculated and evaluated. In addition, a flat steel weight measuring 0.296 m x 0.296 m x 0.015 m was used as the flat weight 31.

First, the fresh concrete 60 minutes after mixing was poured into the internal space R of the formwork 2 from the side wall opening 25, and poured to a height of 0.1 m from the lower end of the earth pressure gauge, i.e., the bottom plate 21, to form the base layer 81. Next, the fresh concrete was poured into the internal space R of the formwork 2 from the side wall opening 25, and poured to a height of 0.5 m from the upper end of the base layer 81, to form the first fresh concrete layer 82. In forming the fresh concrete layer 82, the measurement of the lateral pressure was started at the same time as the fresh concrete was poured.

For the second and subsequent layers, flat weights 31 were placed on the first layer of fresh concrete 82 to measure the lateral pressure. For the second layer, ten flat weights 31 were placed in sequence from the side wall opening 25 after a predetermined time had elapsed since the first layer of fresh concrete had been poured, and were placed on the first layer of fresh concrete 82. The total mass of the flat weights 31 to be loaded per layer was determined based on the mass of the fresh concrete per layer. Specifically, since the mass of the fresh concrete per layer was 103 kg, the total mass of the flat weights 31 to be loaded per layer was also set to 103 kg, and ten flat weights 31 with a mass of 10.3 kg per sheet were loaded. After all the flat weights 31 for the second layer were loaded, flat members 51 were installed as shutter materials 5.

From the third layer onwards, flat plate-shaped weights 31 were loaded in the same way as for the second layer, and the measurement of lateral pressure was terminated when loading of the flat plate-shaped weights 31 for the seventh layer was completed. The results of the lateral pressure measurements are shown in Figure 4. The total height of the flat plate-shaped weights 31 loaded from the second to seventh layers was 0.9 m, and the height from the base layer 81 to the seventh layer was 1.5 m.

When measuring lateral pressure using the lateral pressure test device 1, the overall height of the formwork can be significantly lowered and the amount of fresh concrete poured can be reduced compared to conventional lateral pressure measurement methods in which only fresh concrete is placed in the internal space. From the above, the lateral pressure test device, formwork, and lateral pressure measurement method that satisfy all of the constituent requirements of the present invention can improve the work efficiency of lateral pressure tests.

Reference Signs List 1: Side pressure test device 2: Formwork 3: Weight 4: Pressure gauge 5: Shutter material 6: Base 7: Reinforcement material 21: Bottom plate portion 22: Side wall portion 22a: First region 22b: Second region 25: Side wall opening portion 26: Guide portion

Claims (6)

A lateral pressure test device for measuring the lateral pressure acting on a formwork from fresh concrete,
A formwork including a bottom plate portion and a cylindrical side wall portion erected above the bottom plate portion and forming an internal space;
At least one weight configured to be accommodated in the internal space and having a density greater than the density of the fresh concrete;
At least one pressure gauge is disposed on the side wall portion and measures a lateral pressure acting on the formwork from the fresh concrete,
The side wall portion includes a first region formed so that the fresh concrete can be accommodated in the internal space, and a second region formed continuously above the first region and so that the weight can be accommodated in the internal space.
The second area includes a side wall opening portion that opens the internal space laterally, and is configured so that the fresh concrete and the weight can be poured into the internal space from the side wall opening portion.
Lateral pressure test device. The lateral pressure testing device according to claim 1 further comprises a shutter material that closes the side wall opening. The lateral pressure test device according to claim 1 or 2, wherein the pressure gauge is positioned at a distance of 10 cm to 30 cm above the bottom plate. A formwork used in the lateral pressure test apparatus according to any one of claims 1 to 3,
The container is composed of a bottom plate portion and a cylindrical side wall portion that is erected above the bottom plate portion and forms an internal space,
The side wall portion includes a first region formed so as to be able to accommodate fresh concrete in the internal space, and a second region formed continuously above the first region and so as to be able to accommodate a weight in the internal space,
The second region includes a side wall opening portion that opens the internal space laterally.
Formwork. A lateral pressure measuring method for measuring a lateral pressure acting on a formwork from fresh concrete using the lateral pressure test device according to any one of claims 1 to 3,
a pouring step of pouring the fresh concrete into the internal space of the formwork from the side wall opening and pouring the concrete to a height that covers at least the pressure gauge;
a loading step of loading the weight into the internal space of the formwork from the side wall opening after the driving step and loading the weight onto the fresh concrete;
A lateral pressure measuring process is provided in which, in parallel with the pouring process and the loading process, the lateral pressure acting on the formwork from the fresh concrete is measured using the pressure gauge.
How to measure lateral pressure. The lateral pressure measurement method according to claim 5, wherein the fresh concrete is poured in layers during the pouring process.