CN111595656A - Forming mold and preparation method for testing dissimilar concrete interface fracture performance - Google Patents

Abstract

A forming die and a preparation method for testing the fracture performance of a dissimilar concrete interface are disclosed, the forming die comprises a bottom plate, two front and rear baffle plates, two left and right baffle plates, an isolation baffle plate and a pre-embedded plate, wherein the bottom plate, the front and rear baffle plates and the left and right baffle plates are vertically fixed to form a forming die cavity of a dissimilar concrete composite test piece, and a cubic bulge extending downwards to the bottom plate from the top end is arranged in the middle of one of the left and right baffle plates; two side ends of the isolation baffle are respectively fixed on the cubic bulge and the opposite sides of the other left baffle and the right baffle; one side end of the embedded plate is fixed on the cubic bulge, and the other opposite side end is suspended. The invention also provides a method for preparing a dissimilar concrete composite test piece by using the forming die, which has the advantages of simple operation, low cost and reusability, accurately controls the interface position of dissimilar concrete, ensures that materials are not mixed with each other at the interface position, reveals the law of the fracture performance of the interface of the dissimilar concrete, and provides technical support for the design of a dissimilar concrete structure.

Description

Forming mold and preparation method for testing dissimilar concrete interface fracture performance

technical field

The invention relates to the field of hydraulic structures, in particular to a forming mold and a preparation method for testing the interface fracture performance of dissimilar concrete.

Background technique

The dam is the core main building in the water conservancy project, and its safety is the key to the whole project. The different parts of the dam body have different working conditions, and the defects caused by the differences in "structural properties" and "material properties" of each part of the dam body are directly related to the quality and durability of the engineering structure. How to consider the influence of the splitting tensile strength of dissimilar concrete interfaces through laboratory experiments is one of the research directions of hydraulic structures. At present, the concrete specimen splitting tensile strength measurement molds used in the laboratory mostly measure a single concrete material, and it is difficult to use the above molds to prepare clear interface The composite specimen that can measure the splitting tensile strength of dissimilar concrete cannot reflect the influence of the interfacial bonding effect of dissimilar concrete on the splitting tensile strength in hydraulic structure engineering.

SUMMARY OF THE INVENTION

In view of this, the main purpose of the present invention is to provide a forming mold and a preparation method for testing the interface fracture performance of dissimilar concrete, in order to at least partially solve the above-mentioned technical problems.

The present invention is achieved through the following technical solutions:

As an aspect of the present invention, there is provided a forming mold for testing the fracture performance of dissimilar concrete interfaces, comprising a bottom plate, two front and rear baffles, two left and right baffles, an isolation baffle and a pre-embedded plate, wherein: two The front and rear baffles are respectively vertically fixed on the bottom plate; the two left and right baffle plates are respectively vertically fixed on the bottom plate and the two front and rear baffle plates to form a molding cavity of a dissimilar concrete composite test piece, wherein The middle of a left and right baffle is provided with a cubic protrusion extending downward from the top to the bottom plate; an isolation baffle, the two side ends of the isolation baffle are respectively fixed on the cubic protrusion and the opposite side of the other left and right baffles. side, and a sub-mold cavity for forming concrete on one side of the dissimilar concrete composite specimen is isolated from the molding cavity, and the side of the isolation baffle facing the sub-mold cavity has a connection with the pre-embedded cavity. The same radian of the plate is used to make the crack profile when the concrete is formed on the one side; the embedded plate, one end of the embedded plate is fixed on the cubic protrusion, and the other opposite side end is suspended, so The embedded plate is used to replace the isolation baffle plate after the concrete on one side is formed, so as to make another crack profile through the embedded plate when the other side of the dissimilar concrete composite specimen is concretely formed. The two said crack profiles together form a prefabricated crack at the dissimilar concrete interface.

As another aspect of the present invention, there is provided a method for preparing a dissimilar concrete composite test piece using the above-mentioned forming mold for testing the interface fracture performance of dissimilar concrete, comprising the following steps: forming a base plate, two front and rear baffles and The two left and right baffles are fixed perpendicularly to form the molding cavity of the dissimilar concrete composite specimen; the two sides of the isolation baffle are respectively fixed to the cubic protrusion of one of the left and right baffles and the other left and right baffles On the opposite side of the upper mold cavity, a sub-mold cavity is isolated in the molding cavity, and the side surface with the arc of the isolation baffle faces the sub-mold cavity; apply mold release oil on the molding mold in the sub-mold cavity , fill up with a concrete mixture, and vibrate until the top of the front and rear baffles and the left and right baffles have slurry flowing out, and carry out demoulding treatment under temperature control; remove the isolation baffle and fix the embedded board on the On the cubic protrusion, apply demoulding oil on the forming mold in the remaining space of the forming cavity, fill up with another concrete mixture, and vibrate until the top of the front and rear baffles and the left and right baffles has slurry flowing out. and carrying out demoulding treatment and maintenance of the obtained test piece mould under temperature control to obtain the dissimilar concrete composite test piece.

According to another aspect of the present invention, there is provided a dissimilar concrete composite test piece prepared by using the above-mentioned method for preparing a dissimilar concrete composite test piece, which has a groove at the interface of the dissimilar concrete and is formed from the concave cavity. A prefabricated crack in which the bottom surface of the groove extends inward along the interface.

Based on the above technical solutions, the forming mold and preparation method for testing the interface fracture performance of dissimilar concrete of the present invention have at least one or a part of the following beneficial effects:

(1) The present invention uses a specific isolation baffle, which has one side of the same radian as the embedded board. During the preparation of the dissimilar concrete composite specimen, the interface position of the dissimilar concrete does not occur by cooperating with other components. Concrete intermixing phenomenon, and can precisely control the interface position of dissimilar concrete;

(2) The forming mold of the present invention has the advantages of simple operation, low cost and reusability, and the prepared dissimilar concrete specimen has prefabricated cracks at the interface position, which is suitable for testing the fracture performance of the dissimilar concrete interface by the wedging method , in order to reveal the law of the fracture performance of the dissimilar concrete interface and provide technical support for the design of the dissimilar concrete structure of the hydraulic structure.

Description of drawings

1A is a schematic structural diagram of a forming mold for testing the fracture performance of dissimilar concrete interfaces according to an embodiment of the present invention;

FIG. 1B is a schematic structural diagram of replacing the isolation baffle in FIG. 1A with a pre-embedded plate;

Fig. 2 is the structural representation of the bottom plate in Fig. 1A;

Fig. 3 is the structural representation of the front and rear baffles in Fig. 1A;

4A is a schematic structural diagram of the left and right baffles with cubic protrusions in FIG. 1A;

4B is a schematic structural diagram of another left and right baffle in FIG. 1A;

Fig. 5 is the structural representation of isolation baffle in Fig. 1A;

FIG. 6 is a schematic structural diagram of the embedded board in FIG. 1B .

In the above drawings, the meanings of the reference symbols are as follows:

1 is the bottom plate, 2 is the front and rear baffles, 3 and 3' are the left and right baffles, 4 is the cubic protrusion, 5 is the isolation baffle, 6 is the embedded plate, 7 is the first groove, and 8 is the second groove , 9 and 9' are the third grooves.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be noted that the directional terms mentioned in the embodiments, such as "up", "down", "front", "rear", "left", "right", etc., only refer to the directions of the drawings, not to limit the scope of protection of the present invention. Throughout the drawings, the same elements are denoted by the same or similar reference numbers. Conventional structures or constructions will be omitted when it may lead to obscuring the understanding of the present invention.

According to some embodiments of the present invention, as shown in FIG. 1A to FIG. 6 , there is provided a forming mold for testing the interface fracture performance of dissimilar concrete, especially a forming mold for testing the interface fracture performance of dissimilar concrete by wedging and splitting method The mould, the forming mould comprises a bottom plate 1, two front and rear baffles 2, two left and right baffles 3, 3', an isolation baffle 5 and a pre-embedded plate 6, wherein: two front and rear baffles 2, respectively, are vertically fixed on On the base plate 1; two left and right baffles 3, 3' are respectively fixed on the base plate 1 and the two front and rear baffles 2 to form a molding cavity for a dissimilar concrete composite specimen, wherein the middle of one left and right baffle 3 is provided There is a cubic protrusion 4 extending downward from the top to the bottom plate 1; the isolation baffle 5, the two sides of which are respectively fixed on the opposite side of the cubic protrusion 4 and the other left and right baffles 3', and in the forming cavity A sub-mold cavity for forming one side of the dissimilar concrete composite specimen is isolated, and the side of the isolation baffle plate 5 facing the sub-mold cavity has the same radian as the embedded plate 6, which is used when one side of the concrete is formed. Make the crack profile; the embedded plate 6, one end of which is fixed on the cubic protrusion 4, and the other opposite side is suspended, the embedded plate 6 is used to replace the isolation baffle 5 after the concrete is formed on one side, so as to prevent the dissimilar On the other side of the concrete composite specimen, another crack profile is made through the embedded plate 6 when the concrete is formed, and the two crack profiles jointly form a prefabricated crack at the interface of dissimilar concrete.

As shown in Figure 1A, Figure 1B, Figure 2 and Figure 3, the bottom plate 1 is provided with a first groove 7 into which two front and rear baffles 2, two left and right baffles 3, 3' are respectively inserted. The depth of a groove 7 is 4mm to 8mm; the two front and rear baffles 2 are respectively provided with two second grooves 8 penetrating from top to bottom. It is fixedly connected with the front and rear baffles 1 , and preferably, the depth of the second groove 8 is 4 mm˜8 mm. Through the insertion connection of the bottom plate 1, the front and rear baffles 2 and the left and right baffles 3, 3', the positioning can be pre-positioned before the same fixing, so as to facilitate the subsequent fixing operation.

Based on this, bolts are used to fix between the bottom plate 1 and the front and rear baffles 2, between the bottom plate 1 and the left and right baffles 3, 3', and between the front and rear baffles 2 and the left and right baffles 3, 3', but not limited to this . In some embodiments, the forming die further comprises at least two sets of vertical bolts, respectively passing through the bottom plate 1 and abutting against the outer sides of the front and rear baffles 2 to vertically fix the bottom plate 1 and the front and rear baffles 2; and at least four sets of horizontal bolts Bolts, wherein at least two sets of horizontal bolts pass through the left and right sides of the lower half of the front and rear baffles 2 respectively, and at least two sets of horizontal bolts pass through the left and right sides of the upper half of the front and rear baffles 2 respectively. By tightening the bolts, the front and rear baffles 2 clamp the left and right baffles 3 and 3' to realize the vertical fixing of the front and rear baffles and the left and right baffles.

Here, "vertical bolts" and "horizontal bolts" distinguish the bolts in the direction of use of the bolts when the bottom plate is placed horizontally. The bolts are still commonly used in the field, and a set of horizontal bolts or a set of vertical bolts includes a screw rod and a nut. Although not shown in the figure, the above-mentioned fixing structure should be easily understood based on the conventional bolt structure and fixing method in the mold.

As shown in Fig. 1A, Fig. 1B, Fig. 4A and Fig. 4B, two opposite third grooves 9, 9' are provided on the cubic protrusion 4 and the other left and right baffles 3'. Wherein, the width of the third groove 9 of the cubic protrusion 4 is the same as the thickness of one side end of the isolation baffle 5, so that the side end of the isolation baffle 5 is inserted into the third groove 9 for fixing; the other left and right baffles The third groove 9' of 3' has the same thickness as another opposite side end of the isolation baffle 5, so that the opposite side end of the isolation baffle 5 is inserted into the third groove 9' for fixing. This plug-in fixing method is beneficial for the isolation baffle 5 to be stably fixed between the two left and right baffles 3 and 3'. The admixture phenomenon, on the other hand, can precisely control the position of the dissimilar concrete interface.

At the same time, the width of the third groove 9 of the cubic protrusion 4 is the same as the thickness of one side end of the embedded board 6, so that the side end of the embedded board 6 can be inserted into the third groove 9 for fixing. As shown in FIG. 5 and FIG. 6 , the side of the embedded plate 6 facing a sub-mold cavity has the same radian as the embedded plate 6 , so that after the side concrete in the sub-mold cavity is formed, the side concrete The contour of the crack is consistent with the contour of the corresponding side of the embedded plate 6, so that when the isolation baffle 5 is replaced by the embedded plate 6 to form the other side of the concrete, it is beneficial to extend the final prefabricated crack in the interface of dissimilar concrete. In some embodiments, as shown in FIG. 6 , the thickness of the embedded plate 6 gradually decreases from one side end to the other opposite side end to form a knife edge, so that the fabricated prefabricated crack has a similar shape.

In some other embodiments, the fixing method of the isolation baffle 5 and the pre-embedded plate 6 is not limited to the plug-in fixing, but can also be, for example, adhesive fixing. It is more inconvenient to install, and the stability is not as good as the plug-in type.

In some embodiments, the bottom plate 1, the front and rear baffle plates 2, the left and right baffle plates 3, 3', the isolation baffle plates 5 and the embedded plates 6 may all be made of steel plates, but are not limited thereto. More specifically, the dimensions of the two front and rear baffles are consistent with respect to length, thickness and height, and the dimensions of the two left and right baffles 3, 3' are consistent with respect to length, thickness and height.

According to some embodiments of the present invention, there is also provided a method for preparing a dissimilar concrete composite specimen by using the above-mentioned forming mold for testing the fracture performance of dissimilar concrete interface, comprising the following steps:

(1) Fix the bottom plate 1, two front and rear baffles 2 and two left and right baffles 3, 3' vertically to form the molding cavity of the dissimilar concrete composite test piece;

Specifically, this step specifically includes:

Insert the two front and rear baffles 2 into the first groove 7 of the bottom plate 1 respectively, and use bolts to fix the bottom plate 1 and the front and rear baffles 2, so that the front and rear baffles are in a completely vertical state; then the two left and right baffles 3, 3' is inserted into the first groove 1 along the second grooves 8 of the two front and rear baffles 1 respectively, and the left and right baffles 3, 3' and the front and rear baffles 1 are fixed with bolts.

(2) The two side ends of the isolation baffle 5 are respectively fixed to the cubic protrusion 4 of one of the left and right baffles 3 and the opposite sides of the other left and right baffles 3', and a sub-mold cavity is isolated in the molding cavity , the side surface of the isolation baffle 5 with an arc faces the sub-mold cavity;

Specifically, this step specifically includes: inserting one end of the isolation baffle 5 into the third groove 9 of the cubic protrusion 4, and inserting the other end into the third groove 9' of the other left and right baffles 3' Inside.

(3) Apply demoulding oil on the forming mold in the sub-mold cavity, fill up with a kind of concrete mixture, and vibrate until the top of the front and rear baffles 2 and the left and right baffles 3 have slurry flowing out, and carry out stripping under temperature control. Mold treatment, such as placing in a temperature-controlled room, and demolding within 24-48 hours;

(4) Remove the isolation baffle 5 and fix the embedded plate 6 on the cubic protrusion 4, apply demoulding oil on the molding mold in the remaining space of the molding cavity, and fill up with another concrete mixture, And vibrate until the top of the front and rear baffles 2 and the left and right baffles 3 have slurry flowing out;

(5) Perform demoulding treatment and curing under temperature control to obtain dissimilar concrete composite test pieces. For example, the test piece mold can be placed in a temperature-controlled room and demolded within 24-48 hours. , and then curing for 27 days.

It can be understood that the dissimilar concrete composite specimen prepared above has a groove at the interface of the dissimilar concrete and a prefabricated crack extending inward from the bottom surface of the groove along the interface. A split pull force is applied to both sides when testing the fracture properties by the wedge split pull method.

The specific embodiments described above further describe the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above-mentioned specific embodiments are only specific embodiments of the present invention, and are not intended to limit the present invention. Within the spirit and principle of the present invention, any modifications, equivalent replacements, improvements, etc. made should be included within the protection scope of the present invention.

Claims (10)

1. The utility model provides a forming die for testing heterogeneous concrete interface rupture performance which characterized in that, forming die includes that bottom plate, two front and back baffles, two control baffle, isolation baffle and pre-buried board, wherein:

the two front and rear baffle plates are respectively and vertically fixed on the bottom plate;

the two left and right baffle plates are respectively and vertically fixed on the bottom plate and the two front and rear baffle plates to form a molding die cavity of the dissimilar concrete composite test piece, and a cubic bulge extending downwards to the bottom plate from the top end is arranged in the middle of one of the left and right baffle plates;

the two side ends of the isolation baffle are respectively fixed on the opposite sides of the cubic bulge and the other left baffle and the right baffle, a sub-cavity for molding one side of the heterogeneous concrete composite test piece is isolated in the molding cavity, and one side of the isolation baffle facing the sub-cavity has the same radian as the pre-embedded plate and is used for manufacturing a crack outline during molding of one side of concrete;

the embedded plate, one side end of embedded plate is fixed in on the cube arch, and the other relative side is unsettled, the embedded plate is used for one side concrete shaping back replacement the division shield to pass through during the opposite side concrete shaping of xenogenesis concrete composite test piece another crack profile of embedded plate preparation, by two the crack profile forms the prefabricated crack of xenogenesis concrete interface department jointly.

2. The forming die of claim 1, wherein two opposite third grooves are formed in the cubic protrusion and the other left and right baffle plates, the third groove of the cubic protrusion is used for inserting and fixing one side end of the isolation baffle plate or one side end of the embedded plate, and the third groove of the other left and right baffle plates is used for inserting and fixing the other opposite side end of the isolation baffle plate.

3. The mold according to claim 1, wherein the thickness of the pre-buried plate gradually decreases from the one side end to the other opposite side end to form a blade.

4. The forming die of claim 1, wherein the bottom plate is provided with first grooves into which the two front and rear baffle plates and the two left and right baffle plates are respectively inserted, and preferably, the depth of the first grooves is 4-8 mm;

two second grooves penetrating from top to bottom are formed in the two front and rear baffles respectively, the left baffle and the right baffle are inserted into the second grooves and are fixedly connected with the front and rear baffles, and the depth of each second groove is preferably 4-8 mm.

5. The molding die according to claim 1, wherein the bottom plate and the front and rear baffle plates, the bottom plate and the left and right baffle plates, and the front and rear baffle plates and the left and right baffle plates are fixed by bolts.

6. The forming die of claim 1, wherein the bottom plate, the front and rear baffle plates, the left and right baffle plates, the isolation baffle plate, and the pre-buried plate are steel plates, respectively; and/or

The two front and rear baffle plates are identical in size with respect to length, thickness and height, and the two left and right baffle plates are identical in size with respect to length, thickness and height.

7. A method for preparing a dissimilar concrete composite test piece by using the forming mold for testing the interface fracture performance of dissimilar concrete according to any one of claims 1 to 6, characterized by comprising the following steps:

vertically fixing a bottom plate, two front and rear baffle plates and two left and right baffle plates to form a molding die cavity of the dissimilar concrete composite test piece;

fixing two side ends of an isolation baffle plate on the cubic bulge of one left baffle plate and the opposite side of the other left baffle plate and the right baffle plate respectively, and isolating a sub-cavity in the forming cavity, wherein the side surface of the isolation baffle plate with radian faces the sub-cavity;

coating demoulding oil on a forming die in the sub-die cavity, filling a concrete mixture, vibrating until slurry flows out from the tops of the front baffle, the rear baffle, the left baffle and the right baffle, and performing demoulding treatment under the temperature control;

removing the isolation baffle and fixing the pre-embedded plate on the cubic bulge, smearing demolding oil on a forming mold in the remaining space of the forming mold cavity, filling another concrete mixture, and vibrating until slurry flows out from the tops of the front baffle, the rear baffle and the left baffle and the right baffle;

and (4) carrying out demoulding treatment and maintenance on the obtained test piece mould under the temperature control to obtain the dissimilar concrete composite test piece.

8. The method according to claim 7, wherein the bottom plate is provided with first grooves into which the two front and rear baffle plates and the two left and right baffle plates are respectively inserted, the two front and rear baffle plates are respectively provided with two second grooves penetrating from top to bottom, and the step of fixing the bottom plate, the two front and rear baffle plates and the two left and right baffle plates to each other specifically comprises:

inserting the two front and rear baffle plates into the first grooves of the bottom plate respectively, and fixing the bottom plate and the front and rear baffle plates by using bolts;

and inserting the left baffle plate and the right baffle plate into the first groove along the second grooves of the front baffle plate and the rear baffle plate respectively, and fixing the left baffle plate and the right baffle plate with the front baffle plate and the rear baffle plate by using bolts.

9. The method of claim 7, wherein the cubic protrusion of one of the left and right baffle plates and the other of the left and right baffle plates are provided with two third recesses facing each other, and the step of fixing both side ends of the separation baffle plate to the cubic protrusion of one of the left and right baffle plates and the opposite side of the other of the left and right baffle plates, respectively, specifically comprises:

and inserting one side end of the isolation baffle into the third groove of the cubic bulge, and inserting the other side end of the isolation baffle into the third groove of the other left baffle and the right baffle.

10. A dissimilar concrete composite specimen produced using the method for producing a dissimilar concrete composite specimen according to any one of claims 7 to 9, which has a groove at a dissimilar concrete interface and a prepared crack extending inward from a bottom surface of the groove along the interface.

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