阅读说明：本技术 一种测试泡沫混凝土膨胀应力和变形分布的装置与方法 (Device and method for testing expansion stress and deformation distribution of foam concrete ) 是由 高小建 黄煌煌 陆秀丽 邓宏卫 于 2019-10-14 设计创作，主要内容包括：一种测试泡沫混凝土膨胀应力和变形分布的装置与方法,属于土木建筑材料性能测试领域。本发明解决了现有的技术无法实现在热养环境下实时、连续测量泡沫混凝土膨胀应力和变形分布的问题。模具为金属材质,模具的底部装设有加热片,模具的侧面装设有温度传感器,所述加热片与所述温度控制箱之间、所述温度传感器与温度控制箱之间以及所述CCD相机与安装有PSP校准系统的电脑之间分别通过导线连接,泡沫混凝土装设在模具内,橡胶薄膜粘接在泡沫混凝土的上表面,且橡胶薄膜的上表面喷涂有压敏涂料层,激发光源及CCD相机分别固设在模具的上方,且激发光源与压敏涂料层之间设置有第一滤光片,CCD相机与压敏涂料层之间设置有第二滤光片。(A device and a method for testing expansion stress and deformation distribution of foam concrete belong to the field of performance testing of civil construction materials. The invention solves the problem that the prior art can not realize the real-time and continuous measurement of the expansion stress and deformation distribution of the foam concrete in the hot-curing environment. The mould is the metal material, and the heating plate has been installed to the bottom of mould, and temperature sensor has been installed to the side of mould, the heating plate with between the temperature control case, between temperature sensor and the temperature control case and the CCD camera is connected through the wire respectively with the computer of installing the PSP calbiration system, and foam concrete is installed in the mould, and rubber film bonds at foam concrete's upper surface, and rubber film's upper surface spraying has the pressure sensitive paint layer, and excitation light source and CCD camera set firmly respectively in the top of mould, and be provided with first light filter between excitation light source and the pressure sensitive paint layer, are provided with the second light filter between CCD camera and the pressure sensitive paint layer.)

1. The utility model provides a test foam concrete expansion stress and deformation distribution's device which characterized in that: it includes mould (1), heating plate (2), rubber film (3), clear cover board (4), excitation light source (5), temperature control box (9) and install PSP calbiration system (11) in the computer, mould (1) is the metal material, and heating plate (2) have been installed to its open-top setting, and temperature sensor (10) have been installed to the bottom of mould (1), and temperature sensor (10) have been installed to the side of mould (1), heating plate (2) with between temperature control box (9), between temperature sensor (10) and temperature control box (9) and between CCD camera (7) and the computer of installing PSP calbiration system (11) respectively through the wire connection, and foam concrete (100) are installed in mould (1), and rubber film (3) bond the upper surface at foam concrete (100), and the upper surface spraying of rubber film (3) has pressure sensitive paint layer, the transparent cover plate (4) is covered on the top of the mold (1), the excitation light source (5) and the CCD camera (7) are fixedly arranged above the mold (1) respectively, a first optical filter (12) is arranged between the excitation light source (5) and the pressure-sensitive coating layer, and a second optical filter (13) is arranged between the CCD camera (7) and the pressure-sensitive coating layer.

2. The apparatus for testing the expansion stress and deformation distribution of foamed concrete according to claim 1, wherein: the die (1) is of a cubic structure, cavities are machined in the side portion and the bottom portion of the die, the heating plate (2) is arranged in the cavity in the bottom portion, and the temperature sensor (10) is arranged in the cavity in the side portion.

3. The apparatus for testing the expansion stress and deformation distribution of foamed concrete according to claim 2, wherein: the number of the temperature sensors (10) is two, and the two temperature sensors are symmetrically arranged in cavities at two sides of the die (1).

4. An apparatus for testing the expansion stress and deformation distribution of foamed concrete according to claim 1, 2 or 3, wherein: the outside of the mould (1) is provided with a heat preservation and insulation layer.

5. The apparatus for testing the expansion stress and deformation distribution of foamed concrete according to claim 4, wherein: the inner side wall of the mould (1) is provided with a polytetrafluoroethylene layer.

6. The apparatus for testing the expansion stress and deformation distribution of foamed concrete according to claim 1, 2, 3 or 5, wherein: an excitation light source (5) is fixedly arranged above the mould (1) through a light source support (6), and a CCD camera (7) is fixedly arranged above the mould (1) through a camera support (8).

7. The apparatus for testing the expansion stress and deformation distribution of foamed concrete according to claim 1, 2, 3 or 5, wherein: the mould (1) is an iron mould.

8. The apparatus for testing the expansion stress and deformation distribution of foamed concrete according to claim 7, wherein: the transparent cover plate (4) is an organic glass cover plate.

9. A method for testing the expansion stress and deformation distribution of foam concrete by using the device of any one of claims 1 to 8, wherein the method comprises the following steps: it comprises the following steps:

pouring foam concrete (100) into the mold (1) until the height of the inner wall of the mold (1) is 1/2-2/3, vibrating to be dense, and then scraping the surface of the foam concrete (100);

step two, uniformly spraying pressure-sensitive paint on the upper surface of the rubber film (3), and polishing after the pressure-sensitive paint is cured to form a pressure-sensitive paint layer;

thirdly, placing the rubber film (3) on the upper surface of the foam concrete (100), and pressing the rubber film to be tightly adhered to the upper surface of the foam concrete (100);

step four, covering the transparent cover plate (4) on the top of the mold (1), opening the excitation light source (5) and the PSP calibration system (11), and adjusting the positions of the excitation light source (5) and the CCD camera (7) to enable ultraviolet light generated by the excitation light source (5) to be uniformly irradiated to the upper surface of the foam concrete (100), and enabling the CCD camera (7) to completely capture the image of the upper surface of the foam concrete (100);

fifthly, adjusting the exposure time of the CCD camera (7) until the CCD camera (7) can shoot a high-resolution image of the upper surface of the foam concrete (100);

setting the target temperature of the temperature control box (9) to be 0-60 ℃, adjusting the shooting frequency of a CCD camera (7) to be 8-30 frames/second, and carrying out statistics on the fluorescence intensity of different positions of the upper surface image of the foam concrete (100) through post-processing software in a PSP calibration system (11) to obtain luminous intensity images in different stress states so as to obtain the surface expansion stress distribution of the restrained foam concrete (100) when being heated;

and seventhly, deducing a corresponding deformation distribution according to the elastic modulus of the foam concrete (100) input in advance and through the constitutive relation sigma of the foam concrete (100) to E epsilon, wherein sigma is the expansion stress of the foam concrete (100), E is the elastic modulus, and epsilon is the expansion strain.

10. The method of claim 9, wherein: the surface roughness of the pressure sensitive coating layer is less than 0.25 mu m, and the thickness of the pressure sensitive coating layer is between 30 and 60 mu m.

Technical Field

The invention relates to a device and a method for testing expansion stress and deformation distribution of foam concrete, belonging to the field of performance testing of civil construction materials.

Background

As is well known, the foam concrete has excellent performances of light weight, high strength, heat preservation, heat insulation, sound insulation, fire resistance, shock absorption, earthquake resistance and the like because the interior of the foam concrete is provided with a large number of closed fine pores. In recent years, foamed concrete has been widely used as a building partition or a filler for non-structural members or structural heat-insulating integrated building members. With the development of fabricated buildings, more attention is paid to building partitions using foam concrete as a filling material. The foam concrete can effectively reduce the self weight of the structure due to low density, reduce the consumption of raw materials and save energy and labor cost in the process of factory preparation, transportation and installation. In actual industrial production, in order to accelerate the turnover efficiency of the formwork and shorten the production period, almost all cement concrete members need to be subjected to steam curing within hours after being poured so as to improve the early strength. However, due to the large amount of air holes in the foam concrete, the thermal expansion of the air under steam curing conditions can cause significant volume expansion of the foam concrete. Under the restraint of the template, the self-expansion compressive stress generated by heating can induce the crack development of the foam concrete, so that the appearance quality and the overall mechanical property of the member are reduced.

In actual industrial production, the volume deformation of the foam concrete under the thermal curing condition is the closest to that of the foam concrete under the steam curing condition, but at present, devices for measuring the volume deformation of the concrete at home and abroad are all carried out under the standard curing or normal-temperature curing condition. For steam curing concrete, because of the reason of maintenance condition, it is complicated to directly lead to realizing the device structure of steam curing, in order to realize the test and be convenient for the test, also can select to replace steam curing condition with hot curing condition, but generally take out the test piece from steaming curing environment or hot curing environment and test again, not only disturbed the concrete intensity development under steam curing or hot curing condition, because remove the test piece in the test process simultaneously, lead to the result accuracy of obtaining relatively poor, can not reflect actual conditions.

Disclosure of Invention

The invention aims to solve the problem that the prior art can not realize real-time and continuous measurement of expansion stress and deformation distribution of foam concrete in a hot-curing environment, and further provides a device and a method for testing the expansion stress and deformation distribution of the foam concrete.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a device for testing expansion stress and deformation distribution of foam concrete comprises a mold, a heating plate, a rubber film, a transparent cover plate, an excitation light source, a light source support, a CCD camera, a camera support, a temperature control box and a PSP calibration system installed in a computer, wherein the mold is made of metal, the top opening of the mold is arranged, the bottom of the mold is provided with the heating plate, the side surface of the mold is provided with a temperature sensor, the heating plate is connected with the temperature control box, the temperature sensor is connected with the temperature control box, the CCD camera is connected with the computer provided with the PSP calibration system through leads, the foam concrete is installed in the mold, the rubber film is adhered to the upper surface of the foam concrete, the upper surface of the rubber film is sprayed with a pressure-sensitive coating layer, the transparent cover plate is covered on the top of the mold, and the excitation light source and the CCD camera are respectively and fixedly arranged above the, and a first optical filter is arranged between the excitation light source and the pressure-sensitive coating layer, and a second optical filter is arranged between the CCD camera and the pressure-sensitive coating layer.

Further, the mould is of a cubic structure, cavities are machined in the side portion and the bottom portion of the mould, the heating plate is arranged in the cavity in the bottom portion, and the temperature sensor is arranged in the cavity in the side portion.

Further, the number of the temperature sensors is two, and the two temperature sensors are symmetrically arranged in cavities of two side parts of the mold.

Further, a heat insulation layer is arranged outside the mold.

Further, the mould inside wall is provided with the polytetrafluoroethylene layer.

Furthermore, the excitation light source is fixedly arranged above the die through the light source support, and the CCD camera is fixedly arranged above the die through the camera support.

Further, the mould is an iron mould.

Further, the transparent cover plate is an organic glass cover plate.

A method for testing the expansion stress and deformation distribution of the foam concrete by adopting the device comprises the following steps:

pouring foam concrete into the mold until the height of the inner wall of the mold is 1/2-2/3, vibrating to be dense, and then leveling the surface of the foam concrete;

step two, uniformly spraying pressure-sensitive paint on the upper surface of the rubber film, and polishing after the pressure-sensitive paint is cured to form a pressure-sensitive paint layer;

thirdly, placing a rubber film on the upper surface of the foam concrete, and pressing the rubber film to be tightly adhered to the upper surface of the foam concrete;

step four, covering a transparent cover plate on the top of the mold, opening an excitation light source and a PSP calibration system, and adjusting the positions of the excitation light source and a CCD camera, so that ultraviolet light generated by the excitation light source can be uniformly irradiated on the upper surface of the foam concrete, and the CCD camera can completely capture the image of the upper surface of the foam concrete;

fifthly, adjusting the exposure time of the CCD camera until the CCD camera can shoot a high-resolution image of the upper surface of the foam concrete;

setting the target temperature of the temperature control box to be 0-60 ℃, adjusting the shooting frequency of a CCD camera to be 8-30 frames/second, and counting the fluorescence intensity of different positions of the upper surface image of the foam concrete through post-processing software in a PSP calibration system to obtain luminous intensity images in different stress states, so as to obtain the surface expansion stress distribution of the restrained foam concrete when being heated;

and seventhly, deducing corresponding deformation distribution according to the elastic modulus of the foam concrete input in advance and through the constitutive relation sigma of the foam concrete to obtain E epsilon, wherein sigma is the expansion stress of the foam concrete, E is the elastic modulus, and epsilon is the expansion strain.

Furthermore, the surface roughness of the pressure sensitive paint layer is less than 0.25 μm, and the thickness is between 30 and 60 μm.

Compared with the prior art, the invention has the following effects:

according to the application, the heat-conducting mould and the heating sheet are arranged, so that the heat curing of the foam concrete is realized; and an excitation light source and a CCD camera are arranged above the die, and the principle that the intensity of fluorescence excited by a photosensitive material irradiated by light waves with specific wavelengths is in direct proportion to the surface stress of the foam concrete is utilized, so that the expansion stress and deformation distribution of the foam concrete in a thermal curing environment can be continuously monitored in real time without moving a foam concrete test piece in the testing process, and the accuracy of a testing result is effectively improved.

The device is simple in structure, convenient to operate and accurate in test result.

Drawings

Fig. 1 is a schematic perspective view of the present invention.

Detailed Description