CN204044152U - A kind of device measuring cement-based material self-constriction amount - Google Patents

Abstract

The utility model relates to a device for measuring the self-shrinkage of cement-based materials, which relates to the field of building materials, and solves the problem that the self-shrinkage of cement-based materials measured by the existing cement-based material self-shrinkage instrument and the actual error are too large to be accurate. To assess the stability of cement-based materials. The main technical solution is: the device for measuring the self-shrinkage of cement-based materials includes a box body and a measuring tube. The box body is provided with a liquid inlet for injecting liquid into the box, and a liquid outlet for discharging the liquid in the box. The mouth and the sealed door for opening the box to put the tested cement-based material into the box; the measuring tube is provided with a scale value, and the measuring tube is set on the top of the box and communicates with the inside of the box. The utility model is mainly used for realizing the accurate measurement of the self-shrinkage of the cement-based material, so as to accurately evaluate the stability of the cement-based material.

Description

A device for measuring self-shrinkage of cement-based materials

technical field

The utility model relates to the field of building materials, in particular to a device for measuring the self-shrinkage of cement-based materials such as concrete by using a volumetric method.

Background technique

With the development of society and the advancement of construction technology, the requirements for cement-based materials such as concrete are also increasing. High-strength, high-performance and even ultra-high-performance cement-based materials have emerged one after another. The common characteristics of these cement-based materials are low water-binder ratio, high cement grade, large amount of cement, and a large amount of finely ground active admixtures. This composition leads to rapid hydration of early cementitious materials, rapid consumption of free water in cement-based materials, and self-drying phenomenon while the internal structure is dense, resulting in a decrease in macroscopic volume. The above-mentioned phenomenon is self-shrinkage. The self-shrinkage of cement-based materials will cause tensile stress inside the cement-based materials, and the tensile stress will increase with the increase of self-shrinkage. When the tensile stress exceeds the ultimate tensile strength of cement-based materials, the cement-based materials will Cracks will be generated, and at the same time, due to the effect of stress concentration, the generated cracks will continue to expand and extend under the action of stress, resulting in the destruction of the cement-based material structure.

In order to find a way to reduce the self-shrinkage of cement-based materials, enhance the stability of the volume of cement-based materials, and control the cracks inside the cement-based materials, it is necessary to regularly measure the self-shrinkage of cement-based materials. The existing cement-based material self-shrinkage measuring instrument mainly measures the change of the linear length of the cement-based material sample by measuring the change of the linear length of the cement-based material sample, and measures the self-shrinkage deformation of the cement-based material through the change of the linear length of the cement-based sample, so as to further measure the cement-based material. volume stability.

The inventor of the utility model found that there is a large error between the change of the linear length of the cement-based material sample measured by the above-mentioned cement-based material self-shrinkage measuring instrument and the actual shrinkage deformation of the cement-based material, so it cannot evaluate the cement-based material well. stability.

Utility model content

In view of this, the embodiment of the utility model provides a device for measuring the self-shrinkage of cement-based materials. The main purpose is to accurately measure the self-shrinkage of cement-based materials, so as to accurately evaluate the stability of cement-based materials.

In order to achieve the above object, the utility model mainly provides the following technical solutions:

On the one hand, the embodiment of the utility model also provides a device for measuring the self-shrinkage of cement-based materials, the device includes:

The box body is provided with a liquid inlet for injecting liquid into the box, a liquid outlet for discharging the liquid in the box, and a liquid outlet for opening the box to put the cement-based material to be tested into a sealed door in the box;

A measuring tube is provided with a scale value, and the measuring tube is arranged on the top of the box and communicates with the inside of the box.

As in the aforementioned device for measuring the self-shrinkage of cement-based materials, the box is further provided with a suspension structure for suspending the tested cement-based material in the box.

In the device for measuring the self-shrinkage of cement-based materials as described above, the liquid inlet is connected with a liquid inlet pipe, and the liquid inlet pipe is provided with a liquid flow meter at a position close to the liquid inlet for measuring The volume of liquid injected into the tank.

As the aforementioned device for measuring the self-shrinkage of cement-based materials, a horizontal adjustment device is connected under the bottom of the box; the horizontal adjustment device includes a plurality of horizontal adjustment screws and a level;

The level adjusting screw is arranged at the bottom of the box for adjusting the level of the box;

The spirit level is placed horizontally on the box body to detect whether the box body is in a horizontal state.

As the aforementioned device for measuring the self-shrinkage of cement-based materials, the box has a top plate, a bottom plate, and a side plate connected to the top plate and the bottom plate;

The material of the side plate of the box is plexiglass, and the material of the bottom plate of the box is steel.

In the aforementioned device for measuring self-shrinkage of cement-based materials, the measuring tube is a capillary, and the diameter of the capillary is 0.05-1mm.

In the aforementioned device for measuring self-shrinkage of cement-based materials, the end of the measuring tube far away from the box is open.

A device for measuring the self-shrinkage of cement-based materials proposed by the embodiment of the utility model has at least the following advantages:

The device for measuring the self-shrinkage of the cement-based material provided by the embodiment of the utility model needs to place the cement-based material to be tested in the box, inject liquid into the box, and make the liquid level of the liquid be in the measuring tube. By placing the cement-based material before and after the curing period in the box, injecting the same amount of water into the box, and according to the difference in the liquid level in the measuring tube, the self-shrinkage of the cement-based material during the curing period can be obtained. And the autogenous shrinkage of the cement-based material is that under the condition that its quality is constant, the phenomenon that its volume reduces, compared with the change of the linear length of the cement-based material by measuring the cement-based material in the prior art (the change of the linear length It cannot be equated with the volume change of the cement-based material, so its error is relatively large, and the self-shrinkage deformation of the cement-based material cannot be well evaluated in this way), the embodiment of the utility model can measure the self-shrinkage volume of the cement-based material, which is closer to Therefore, the error between the self-shrinkage measured by the self-shrinkage device of the cement-based material provided in this example and the actual amount is small, and the self-shrinkage deformation of the cement-based material can be better evaluated.

Furthermore, the device for measuring the self-shrinkage of cement-based materials provided by the embodiment of the present invention only needs a box and a measuring tube installed on the top of the box to perform the measurement test, so it has a simple structure and low cost.

Further, the measuring tube in the device for measuring the self-shrinkage of cement-based materials provided by the embodiments of the present invention adopts capillary tubes. Due to the high precision of the capillary tubes, it can more accurately measure the self-shrinkage of cement-based materials.

Further, the device for measuring the self-shrinkage of cement-based materials provided by the embodiment of the utility model is provided with a level adjustment device at the bottom of the box to adjust the level of the box to keep the box level, so as not to affect the reading of the liquid level in the measuring tube , resulting in inaccurate measurements.

Further, the device for measuring the self-shrinkage of cement-based materials provided by the embodiments of the present invention suspends the cement-based sample to be tested in the box by using a suspension structure, so as to reduce the friction between the cement-based sample and the box, so that Changes in the structure of the cement-based sample to be tested lead to other types of deformation and affect the measurement results.

The above description is only an overview of the technical solution of the utility model. In order to understand the technical means of the utility model more clearly and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiment of the utility model with accompanying drawings. back.

Description of drawings

Fig. 1 is a schematic structural view of a device for measuring the self-shrinkage of cement-based materials provided by an embodiment of the present invention;

Fig. 2 is a schematic structural view of a device for measuring autogenous shrinkage of cement-based materials provided by another embodiment of the present invention.

Detailed ways

In order to further explain the technical means and effects of the utility model to achieve the intended purpose of the utility model, the specific implementation, structure, features and effects of the utility model application are described in detail below in conjunction with the accompanying drawings and preferred embodiments. The description is as follows. In the following description, different "one embodiment" or "embodiment" do not necessarily refer to the same embodiment. Furthermore, the particular features, structures, or characteristics of one or more embodiments may be combined in any suitable manner.

As shown in FIG. 1 , an embodiment of the present invention provides a device for measuring self-shrinkage of cement-based materials. The device includes a box body 1 and a measuring tube 2 . Wherein, the casing 1 is provided with a liquid inlet 11 for injecting liquid into the casing 1, a liquid outlet 12 for discharging the liquid in the casing 1, and a liquid outlet 12 for opening the casing 1, so that the cement to be tested The base material is put into the airtight door 13 in the casing 1 . The measuring tube 2 is provided with a scale value, and the measuring tube 2 is arranged on the top of the box body 1 and communicates with the inside of the box body 1 .

When the device for measuring the self-shrinkage of cement-based materials provided by this embodiment is used to measure the self-shrinkage of cement-based materials, first open the airtight door 13 arranged on the box body 1 to place the cement-based sample to be measured in the box body 1, Close the airtight door 13, then fill the tank 1 with liquid (the injected liquid is preferably water) through the liquid inlet 11 arranged on the tank 1, and make the liquid level in the tank 1 rise to the measuring tube 2 (you can also fill the tank with liquid first, and then drop liquid into the vector tube, so that the liquid level of the liquid corresponds to a certain scale value on the measuring tube), record the scale value, and record The total amount of liquid injected down. Afterwards, after the liquid in the box is discharged through the liquid outlet 12 arranged on the box body, the sealed door 13 is opened to take out the cement-based sample to be tested, and put it into a conventional curing box for curing. , put the cement-based sample to be tested into the box body 1 of the device provided in this embodiment again, and inject the same amount of liquid as in the above steps into the box body 1, and record the liquid level in the measuring tube 2 at this time The scale value of , the self-shrinkage of the cement-based material to be tested can be obtained by the difference of the liquid level in the measuring tube 2 twice.

Self-shrinkage of cement-based materials is a phenomenon in which the volume of the cement-based materials shrinks when its mass remains unchanged, while the cement-based material measuring instrument in the prior art only measures the change of the linear length of the cement-based material. There is a big difference in volume change, and it is an imprecise measurement to measure the autogenous shrinkage (volume change) of cement-based materials by linear length change. Compared with the measurement of the cement-based material in the prior art, which only measures the linear length change of the cement-based material, the embodiment of the utility model can obtain the volume change of the cement-based material to be measured through the change of the liquid level in the measuring tube twice before and after, that is, The self-shrinkage volume of the cement-based material is measured, which is closer to the actual shrinkage. Therefore, the self-shrinkage of the cement-based material self-shrinkage device provided in this example has a small error with the actual shrinkage, which can better evaluate the cement-based material. self-shrinkage deformation.

Preferably, as shown in Figure 1, another embodiment of the present invention proposes a device for measuring the self-shrinkage of cement-based materials. The structure 3 is used to hang the cement-based sample to be tested in the box 1 . Suspension structure 3 can adopt hook. By hanging the cement-based sample in the box instead of placing it at the bottom of the box, it is possible to avoid changes in the structure of the cement-based sample to be tested due to the friction between the box and the cement sample to be tested. Other types of deformation can affect the measurement results.

As shown in Figure 2, preferably, another embodiment of the present utility model proposes a device for measuring the self-shrinkage of cement-based materials. The shrinkage device also includes a level adjustment device, which is used to keep the box body 1 in a horizontal state, so as to make the measurement more accurate. Specifically, the level adjustment device includes a plurality of level adjustment screws 4 and a level bar 5 . Wherein a plurality of horizontal adjustment screws are arranged on the bottom of casing 1, and level ruler 5 is horizontally arranged on casing 1 (can be arranged on the top of casing, or inner bottom, and other places that are convenient for observation). The levelness of the cabinet can be adjusted through the level adjustment screw, and whether the cabinet is in a horizontal state can be detected according to the reading of the spirit level.

Preferably, another embodiment of the present utility model proposes a device for measuring the self-shrinkage of cement-based materials. Compared with the above-mentioned embodiment, the liquid outlet 12 in this embodiment is preferably arranged near the side end of the box body 1. position at the bottom. The liquid inlet 11 is preferably arranged at the top of the box body 1 , and the airtight door 13 is preferably arranged at the top of the box body 1 . In addition, the liquid inlet 11 and the liquid outlet 12 are respectively provided with valves for controlling water inlet and outlet.

Preferably, another embodiment of the utility model proposes a device for measuring the self-shrinkage of cement-based materials. Compared with the above-mentioned embodiment, the liquid outlet 12 in this embodiment is connected with a liquid outlet pipe, and is connected with the outlet The liquid pipeline is sealed and connected, and an on-off valve is arranged on the liquid outlet pipeline. The liquid inlet 11 is connected with a liquid inlet pipe, and is sealed and connected with the liquid inlet pipe through a sealing ring. Preferably, the liquid inlet pipe is provided with a volume capacity meter near the liquid inlet 11 to record the volume of liquid injected into the tank 1 .

Preferably, the box body 1 in the above embodiment has a top plate and a bottom plate and side plates connected with the top plate and the bottom plate. The measuring tube 2 is arranged on the top plate, and the top plate is also provided with a liquid inlet and a sealed door; the liquid outlet is arranged on the side plate. Preferably, the material of the side panels of the box body 1 is plexiglass, and the material of the bottom plate of the box body 1 is steel. In addition, the material of the measuring tube 2 is glass.

Preferably, the end of the measuring tube 2 in the above embodiment is open and set away from the box body 1, so that the environment inside the box is consistent with the outside world.

Preferably, the measuring tube 2 in the above embodiment is a capillary, and the diameter of the capillary is 0.05mm-1mm. The smaller the diameter of the capillary, the higher the accuracy of measuring the self-shrinkage of the cement-based material, and the accuracy can reach 5 μm.

Preferably, sealing rings are respectively provided at the sealing door, the liquid inlet and the liquid outlet in the above embodiment to prevent the liquid in the tank from leaking out.

When utilizing the device for measuring the self-shrinkage of cement-based materials provided in the above-mentioned embodiments to measure the self-shrinkage of cement-based materials, it mainly includes the following steps:

1. Pour the cement-based material to be tested into an elastic bag, and after vacuuming, form a sample to be tested with a sealed structure;

In this step, the cement-based material to be tested is poured into a well-sealed elastic bag, and vacuumed so that the elastic bag is in sealing contact with the cement-based material, so as to avoid enclosing air in the elastic bag. Therefore, when the cement-based material undergoes self-shrinkage deformation, the elastic bag will undergo self-shrinkage deformation along with the cement-based material. In addition, the elastic bag with a good sealing structure can prevent the cement-based material to be tested from contacting the liquid injected into the box and give the cement to be tested. The self-shrinkage deformation of the base material is affected. The elastic bag in this step is preferably a rubber bag.

2. Place the sample to be tested in the box, inject liquid into the box from the liquid inlet, and let the liquid enter the measuring tube, record the scale value of the liquid level in the measuring tube and the total amount of liquid injected into the box;

3. Take the sample to be tested out of the box and put it into the curing box for curing;

In this step, after the sample to be tested is taken out of the box, the liquid in the box is discharged from the liquid outlet.

4. After the specified curing period, place the sample to be tested in the box, and inject liquid into the box from the liquid inlet, and the total amount of liquid injected is consistent with the total amount of liquid injected in the above steps. Record the The scale value of the liquid level in the measuring tube;

5. According to the difference between the two liquid levels in the measuring tube, the self-shrinkage value of the cement-based material can be obtained.

Among them, the self-shrinkage of cement-based materials can be calculated using the following formula:

V=π×(D/2) ² ×(MN);

Among them, M is the scale value of the liquid level in the measuring tube when the sample to be tested is placed in the device for measuring the self-shrinkage of cement-based materials before the curing period, and N is the scale value of the liquid level in the measuring tube after the curing period. The scale value of the liquid level in the measuring tube when the self-shrinking amount of the cement-based material is in the device, V is the self-shrinking volume of the cement-based material to be tested after the specified curing period, and D is the diameter of the measuring tube.

In summary, the device for measuring the self-shrinkage of cement-based materials provided by the embodiments of the present invention needs to place the cement-based material to be tested in the box, inject liquid into the box, and make the liquid level of the liquid in the measuring tube. By placing the cement-based material before and after the curing period in the box, injecting the same amount of water into the box, and according to the difference in the liquid level in the measuring tube, the self-shrinkage of the cement-based material during the curing period can be obtained. And the autogenous shrinkage of cement-based materials is the phenomenon that its volume decreases under the condition that its quality is constant, compared with the measurement of cement-based materials in the prior art that only measures the linear length change of cement-based materials (linear length The change cannot be equal to the change of the cement-based material volume, so its error is relatively large, and the self-shrinkage deformation of the cement-based material cannot be well evaluated like this), the utility model embodiment can measure the self-shrinkage volume of the cement-based material, more It is close to the actual shrinkage, so the error between the self-shrinkage measured by the self-shrinkage device of the cement-based material provided in this example and the actual value is small, and the self-shrinkage deformation of the cement-based material can be better evaluated.

The above is only a preferred embodiment of the utility model, and does not limit the utility model in any form. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the utility model are all valid. Still belong to the scope of the technical solution of the utility model.

Claims (7)

1. measure a device for cement-based material self-constriction amount, it is characterized in that, this device comprises:

Casing, it offers the inlet for injecting liquid in described casing, for by described casing liquid discharge liquid outlet and be used for opening described casing tested cement-based material to be put into the hermatic door of described casing;

Buret, is provided with scale value, and described buret is arranged on the top of described casing, and is communicated with described box house.

2. device according to claim 1, is characterized in that, is also provided with suspended structure in described casing, for being suspended in described casing by tested cement-based material.

3. device according to claim 1, is characterized in that, described inlet is connected with input duct, and described input duct is provided with liquid flowmeter in the position near described inlet, for measuring the volume injecting liquid in described casing.

4. device according to claim 1, is characterized in that, is connected with level(l)ing device under described bottom half; Described level(l)ing device comprises multiple horizontal adjustment screw and surveyor's staff;

Described horizontal adjustment screw is arranged on the bottom of described casing, for regulating the levelness of described casing;

Whether described surveyor's staff horizontal setting, on casing, is in horizontality to detect described casing.

5. device according to claim 1, is characterized in that, the side plate that described casing has top board, base plate and is connected with described top board, base plate;

The material of the side plate of described casing is organic glass, and the material of described box bottom is steel.

6. device according to claim 1, is characterized in that, described buret is kapillary, and the diameter of described kapillary is 0.05-1mm.

7. the device according to any one of claim 1-6, is characterized in that, the open at one end away from described casing of described buret is arranged.