CN107643243B - Device and method for measuring porosity distribution of pervious concrete - Google Patents

Abstract

The invention discloses a device and a method for measuring the porosity distribution of pervious concrete. The height adjusting device comprises a vernier, the vernier is installed on the upper portion of the vernier in a sliding fit mode, a fine adjusting device is installed above the vernier, and a hanging claw is fixed on the side wall of the vernier. The measuring device comprises a carrying device, a measuring cylinder and a water accumulation container. The device adopts an electronic digital display and fine adjustment device, can accurately control the position of a sample, can obtain the overall average porosity of the pervious concrete by measuring the water quantity discharged by a sample framework with a certain thickness, can obtain the porosity with a certain thickness at any position, and can obtain the porosity distribution of the pervious concrete by measuring the porosity with a certain thickness in sequence.

Description

Measuring device and method for porosity distribution of permeable concrete

technical field

The invention belongs to the technical field of testing porosity of porous media, and in particular relates to a measuring device and method for porosity distribution of permeable concrete.

Background technique

The porous structure of pervious concrete makes the pavement have good water permeability, and rainwater can quickly seep into the ground, thereby effectively reducing or eliminating flood disasters caused by urban rainstorms. This plays an important role in the construction of "sponge cities" that is being implemented in China. In order to be closer to the actual engineering, the permeable concrete samples are mostly formed by static pressure forming or vibration forming, and the porosity distribution after forming is not uniform, especially in the direction of compaction, such as the permeable concrete formed by static pressure Along the direction of compaction, the samples tend to have lower porosity in the upper part and larger porosity in the lower part.

The strength and permeability coefficient of pervious concrete are closely related to the porosity distribution of the sample. For example, the permeability coefficient of pervious concrete often depends on the control section with the smallest area porosity. In addition, the porosity distribution of pervious concrete also affects its plugging law. Therefore, the determination of the porosity distribution of pervious concrete is of great significance to the study of pervious concrete. The existing devices and methods for measuring permeable concrete are mostly buoyancy-based mass method or vacuum sealing method, and the porosity measured by these methods is the average porosity of the entire sample, and it is difficult to measure the porosity distribution.

Contents of the invention

The technical problem to be solved by this invention is to provide a measuring device and method for the porosity distribution of permeable concrete. This device adopts an electronic digital display and a fine-tuning device, which can accurately control the position of the sample. The overall average porosity of pervious concrete can be obtained, and the porosity of a certain thickness at any position can be obtained, and the porosity distribution of permeable concrete can be obtained by sequentially measuring the porosity at a certain thickness.

In order to solve the above-mentioned technical problems, the present invention proposes the following technical solutions: a measuring device for the porosity distribution of permeable concrete, which includes a base, a support shaft is vertically installed on the base, and a height adjustment device is installed on the support shaft. A measuring device is mounted on the height adjustment device.

The support shaft includes a lower rod, on which a middle restricting block is sleeved, the part above the middle restricting block is an upper ruler body, and a top restricting block is fixed on the top of the lower rod.

The height adjustment device includes a vernier, which is slidingly fitted on the upper scale body, a fine-tuning device is installed above the vernier, and a hanging claw is fixed on the side wall of the vernier.

The measuring device includes a loading device, a measuring cylinder and a water storage container.

A plurality of feet are installed on the bottom of the base.

The upper ruler body is marked with scales and is provided with a fixed grid, and the fixed grid cooperates with the movable grid arranged on the vernier scale to form a capacitive grid sensor.

The water accumulation container is provided with an overflow hole and a water inlet hole, and the water inlet hole is provided with a valve.

The object loading device includes a hanging wire, one end of the hanging wire is connected to the object hanging claw, and the other end is connected to a bottom tray, and a large number of holes are arranged on the bottom tray.

The vernier scale is provided with an electronic display screen and a zero return key.

The position where the vernier scale matches the upper ruler body is provided with a second limit screw; the position where the fine-tuning device cooperates with the upper ruler body is provided with a first limit screw.

A vial is provided on the base.

The method for measuring the porosity distribution of permeable concrete by any measuring device for porosity distribution of permeable concrete is characterized in that it includes the following steps:

Step1: Adjust the feet so that the droplet in the vial is in the middle;

Step 2: Loosen the first limit screw and the second limit screw respectively, slide the vernier to the top of the upper body, and tighten the second limit screw and the first limit screw respectively;

Step 3: Place the water storage container on the base, fill the water storage container with water from the water inlet hole until water overflows from the overflow hole, and close the valve;

Step 4: Mount the loading device on the hanging claw, and place the sample on the bottom tray of the loading device;

Step 5: Loosen the first limit screw and the second limit screw respectively, slide the vernier down slowly until the bottom of the sample is close to the bottom of the overflow hole, tighten the first limit screw, and adjust the fine-tuning device to the bottom of the sample and the overflow hole The bottom is even, tighten the second limit screw, and then press the zero return key of the vernier scale;

Step6: Place the measuring cylinder on the base, loosen the first limit screw and the second limit screw respectively, slide the vernier down slowly until the display reads close to mm, tighten the first limit screw, and adjust the fine-tuning device to the display The reading on the screen is m millimeters, tighten the second limit screw, record the reading V1 of the measuring cylinder, the total volume of the pores and the skeleton of the sample m millimeter thick is V, then the porosity of the sample m millimeter thick is n1=(V -V1)/V;

Step 7: According to Step 6, measure the entire sample in turn with a thickness of m mm, and finally obtain the distribution of porosity along the height.

The present invention has following beneficial effect:

1. The present invention can not only measure the overall average porosity of pervious concrete, but also measure the porosity of a certain thickness at any position, and measure the porosity sequentially at a certain thickness to obtain the porosity distribution of permeable concrete.

2. Adopt electronic digital display and fine-tuning device, which can accurately control the position of the sample and measure the porosity of a certain thickness of the sample.

3. The tray, water container, and measuring cylinder can be removed and replaced, which is convenient for handling and can be used for samples of different sizes.

4. Equipped with a level bubble and height-adjustable feet, it can be used on uneven ground.

5. The whole device has a simple structure and is easy to operate.

Description of drawings

The present invention will be further described below in conjunction with drawings and embodiments.

Fig. 1 is a structural schematic diagram of the present invention.

Figure 2 shows the distribution of porosity along the height of the sample in Example 3.

In the figure, base 1, leg 2, lower rod 3, middle limiting block 4, upper ruler body 5, top limiting block 6, level bubble 7, vernier ruler 8, fine-tuning device 9, hanging claw 10, first limit screw 11. Second limit screw 12, measuring cylinder 13, water storage container 14, overflow hole 15, water inlet hole 16, hanging wire 17, bottom tray 18.

Detailed ways

Embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

Example 1:

As shown in Figure 1, the measuring device for the porosity distribution of permeable concrete comprises a base 1, a support shaft is vertically installed on the base 1, a height adjustment device is installed on the support shaft, and a measuring device is installed on the height adjustment device. device.

Further, the support shaft includes a lower rod 3, on which a middle limiting block 4 is sleeved, and the part above the middle limiting block 4 is an upper ruler body 5, and a top limiting block is fixed on the top of the lower rod 3. Block 6. The height adjustment device includes a vernier 8, which is mounted on the upper ruler body 5 by sliding fit, a fine-tuning device 9 is installed above the vernier 8, and a hanging claw is fixed on the side wall of the vernier 8 10. The measuring device includes a loading device, a measuring cylinder 13 and a water storage container 14 .

Further, a plurality of feet 2 are installed on the bottom of the base 1 . The height of the legs 2 can be adjusted, so as to adjust the levelness of the base 1 .

Further, the upper ruler body 5 is marked with a scale and is provided with a fixed grid, and the fixed grid cooperates with the movable grid arranged on the vernier scale 8 to form a capacitive grid sensor.

Further, the water accumulation container 14 is provided with an overflow hole 15 and a water inlet hole 16, and the water inlet hole 16 is provided with a valve.

Further, the object loading device includes a hanging wire 17, one end of the hanging wire 17 is connected to the object hanging claw 10, and the other end is connected to the bottom tray 18, and the bottom tray 18 is provided with a large number of holes. Water penetration is ensured through the holes.

Further, the vernier scale 8 is provided with an electronic display screen and a zero return key. The convenience of reading is ensured by the electronic display, and the zeroing is facilitated by the zeroing key.

Further, a second limit screw 12 is provided at the position where the vernier ruler 8 cooperates with the upper scale body 5 ; a first limit screw 11 is disposed at the position where the fine-tuning device 9 cooperates with the upper scale body 5 . Its position is conveniently adjusted by a limit screw.

Further, a vial 7 is provided on the base 1 .

Example 2:

The method for measuring the porosity distribution of permeable concrete by any measuring device for porosity distribution of permeable concrete is characterized in that it includes the following steps:

Step1: Adjust leg 2 so that the droplet in the vial is in the middle;

Step2: Loosen the first limit screw 11 and the second limit screw 12 respectively, slide the vernier 8 to the top of the upper ruler body 5, and tighten the second limit screw 12 and the first limit screw 11 respectively;

Step 3: Place the water storage container 14 on the base 1, fill the water storage container 14 from the water inlet hole 16 until water overflows from the overflow hole 15, and close the valve;

Step 4: Mount the loading device on the hanging claw 10, and place the sample on the bottom tray 18 of the loading device;

Step 5: Loosen the first limit screw 11 and the second limit screw 12 respectively, slowly slide the vernier 8 down until the bottom of the sample is close to the bottom of the overflow hole 15, tighten the first limit screw 11, and adjust the fine-tuning device 9 to The bottom of the sample is flush with the bottom of the overflow hole 15, tighten the second limit screw 12, and then press the zero return key of the downstream scale 8;

Step 6: Place the measuring cylinder 13 on the base 1, loosen the first limit screw 11 and the second limit screw 12 respectively, slide the vernier 8 down slowly until the reading on the display is close to mm, and tighten the first limit screw 11. Adjust the fine-tuning device 9 until the reading on the display screen is m mm, tighten the second limit screw 12, record the reading V1 of the measuring cylinder 13, the total volume of the sample m mm thick pores and the skeleton is V, then the sample is m The porosity of mm thick is n1=(V-V1)/V;

Step 7: According to Step 6, measure the entire sample in turn with a thickness of m mm, and finally obtain the distribution of porosity along the height.

Example 3:

The sample is a cylindrical permeable concrete obtained by static pressure forming in the laboratory to simulate the actual project. The height and diameter are 120mm and 100mm respectively. The measuring range and accuracy of vernier ruler 8 are 150mm and 0.1mm respectively.

Step 1: Adjust leg 2 so that the droplet in vial 7 is in the middle position;

Step 2: Loosen the first limit screw 11 and the second limit screw 12 respectively, slide the vernier 8 to the top of the upper ruler body 5, and tighten the second limit screw 12 and the first limit screw 11 respectively;

Step 3: Place the water storage container 14 on the base 1, fill the water storage container 14 from the water inlet hole 16 until water overflows from the overflow hole 15, and close the valve;

Step 4: Mount the loading device on the hanging claw 10, place the sample on the bottom tray 18 of the loading device, with the compacting surface above;

Step 5: Loosen the first limit screw 11 and the second limit screw 12 respectively, slowly slide the vernier 8 down until the bottom of the sample is close to the bottom of the overflow hole 15, tighten the first limit screw 11, and adjust the fine-tuning device 9 to The bottom of the sample is flush with the bottom of the overflow hole 15, tighten the second limit screw 12, and then press the zero return key of the downstream scale 8;

Step 6: Place the measuring cylinder 13 on the base 1, loosen the first limit screw 11 and the second limit screw 12 respectively, slide the vernier 8 down slowly until the reading on the display is close to 10mm, and tighten the first limit screw 11 , adjust the fine-tuning device 9 until the reading on the display screen is 10mm, tighten the second limit screw 12, record the reading V1 of the measuring cylinder 13, the total volume of the 10mm-thick pores and the skeleton of the sample is V=10×π×50 ² , then The 10mm thick porosity of the sample is n1=(V-V1)/V;

Step 7: According to Step 6, measure the entire sample in turn with a thickness of 10 mm, and finally obtain the distribution of porosity along the height.

The test results are shown in Table 1 and Figure 2: Table 1 shows the porosity of each layer of the sample; Figure 2 shows the distribution of the sample porosity along the height. The overall average porosity of the sample is 26.05%, but the porosity of each layer varies greatly. The general rule of the sample in the compaction direction is that the porosity in the upper part is small and the porosity in the lower part is large.

Table 1 The porosity of each layer of the sample

Through the above description, those skilled in the art can make various changes and modifications without departing from the technical idea of the present invention, all of which are within the protection scope of the present invention. Matters not covered in the present invention belong to the common knowledge of those skilled in the art.

Claims (3)

1. A method for measuring the porosity distribution of permeable concrete. The method is realized by a measuring device for the porosity distribution of the permeable concrete. The measuring device for the porosity distribution of the permeable concrete includes a base (1) on which A support shaft is installed vertically, a height adjustment device is installed on the support shaft, and a measuring device is installed on the height adjustment device; The support shaft includes a lower rod (3), and a middle limiting block (4) is set on the lower rod (3). The part above the middle limiting block (4) is the upper blade body (5), and (3) is fixed with a top limiting block (6); The height adjustment device includes a vernier (8), the vernier (8) is slidingly fitted on the upper body (5), and a fine-tuning device (9) is installed above the vernier (8). (8) is fixed with a hanging claw (10) on the side wall; The measuring device includes a loading device, a measuring cylinder (13) and a water storage container (14); A plurality of feet (2) are installed on the bottom of the base (1); The water accumulation container (14) is provided with an overflow hole (15) and a water inlet hole (16), and the water inlet hole (16) is provided with a valve; The loading device includes a hanging wire (17), one end of the hanging wire (17) is connected to the hanging claw (10), and the other end is connected to the bottom tray (18), and the bottom tray (18) is set have a large number of holes; The position where the vernier scale (8) matches the upper body (5) is provided with a second limit screw (12); the position where the fine-tuning device (9) cooperates with the upper body (5) is provided with a second A limit screw (11); A vial (7) is provided on the base (1); It is characterized in that the assay method comprises the following steps: Step1: Adjust the leg (2) so that the droplet in the vial (7) is in the middle position; Step 2: Loosen the first limit screw (11) and the second limit screw (12), slide the vernier (8) to the top of the upper body (5), and tighten the second limit screw (12) ) and the first limit screw (11); Step 3: Place the water storage container (14) on the base (1), fill the water storage container (14) from the water inlet hole (16) until water overflows from the overflow hole (15), and close the valve; Step 4: Mount the loading device on the hanging claw (10), and place the sample on the bottom tray (18) of the loading device; Step 5: Loosen the first limit screw (11) and the second limit screw (12), slowly slide the vernier (8) down until the bottom of the sample is close to the bottom of the overflow hole (15), and tighten the first limit Screw (11), adjust the fine-tuning device (9) until the bottom of the sample is flush with the bottom of the overflow hole (15), tighten the second limit screw (12), and then press the zero return key of the downstream scale (8); Step 6: Place the measuring cylinder (13) on the base (1), loosen the first limit screw (11) and the second limit screw (12) respectively, and slowly slide the vernier (8) down to the display reading Close to m mm, tighten the first limit screw (11), adjust the fine-tuning device (9) until the display reads m mm, tighten the second limit screw (12), record the reading V1 of the measuring cylinder (13), sample The total volume of the m mm thick pores and the skeleton is V, then the porosity of the m mm thick sample is n1=(V-V1)/V; Step 7: According to Step 6, measure the entire sample in turn with a thickness of m mm, and finally obtain the distribution of porosity along the height. 2. The method for measuring porosity distribution of permeable concrete according to claim 1, characterized in that: the upper ruler body (5) is marked with a scale and is provided with a fixed grid, and the fixed grid is arranged on the vernier scale (8 ) The moving grid on the grid cooperates to form a capacitive grid sensor. 3. The method for measuring porosity distribution of permeable concrete according to claim 1, characterized in that: the vernier (8) is provided with an electronic display screen and a reset key.

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