阅读说明：本技术 监测约束状态下泡沫混凝土热胀应力和变形的装置与方法 (Device and method for monitoring thermal expansion stress and deformation of foam concrete in constraint state ) 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：一种监测约束状态下泡沫混凝土热胀应力和变形的装置与方法,属于土木建筑材料性能测试技术领域。本发明解决了现有技术无法实现在热养环境下实时、原位测量泡沫混凝土膨胀应力和变形的问题,以及无法测量不同热养环境及约束状态下泡沫混凝土膨胀应力和变形的问题。泡沫混凝土装设在模具内,加热片装设在模具的底部,温度传感器装设在模具的侧面,所述加热片与所述温度控制箱之间以及所述温度传感器与所述温度控制箱之间分别通过导线连接,所述滑道竖向设置在模具的一侧,滑板水平布置且沿竖直方向滑动连接在滑道上,若干弹簧均布在滑板与盖板之间,且其上、下两端分别与滑板及盖板固接,位移传感器装设在滑板下表面中心位置。(A device and a method for monitoring thermal expansion stress and deformation of foam concrete in a constraint state belong to the technical field of civil construction material performance testing. The invention solves the problems that the prior art can not realize the real-time and in-situ measurement of the expansion stress and deformation of the foam concrete in the thermal-curing environment and can not measure the expansion stress and deformation of the foam concrete in different thermal-curing environments and constraint states. Foam concrete installs in the mould, and the heating plate is installed in the bottom of mould, and temperature sensor installs the side at the mould, the heating plate with between the temperature control case and temperature sensor with connect through the wire respectively between the temperature control case, the vertical setting of slide is in one side of mould, and the slide level is arranged and is followed vertical direction sliding connection on the slide, and a plurality of spring equipartitions are between slide and apron, and its upper and lower both ends respectively with slide and apron rigid coupling, and displacement sensor installs and puts at slide lower surface central point.)

1. The utility model provides a device that monitoring foam concrete thermal expansion stress and deformation under restraint state which characterized in that: it comprises a mould (1), a heating plate (2), a temperature sensor (3), a cover plate (4), a sliding plate (5), a slide way (6), a displacement sensor (7), a temperature control box (8) and a plurality of springs (9), wherein the mould (1) is made of metal, the top opening of the mould is arranged, foam concrete (100) is arranged in the mould (1), the heating plate (2) is arranged at the bottom of the mould (1), the temperature sensor (3) is arranged at the side surface of the mould (1), the heating plate (2) is arranged between the temperature control box (8) and the temperature sensor (3) is connected with the temperature control box (8) through leads respectively, the slide way (6) is vertically arranged at one side of the mould (1), the sliding plate (5) is horizontally arranged and is connected on the slide way (6) in a sliding way along the vertical direction, the springs (9) are uniformly distributed between the sliding plate (5) and the cover plate (4), the upper and lower ends of the displacement sensor are respectively fixedly connected with the sliding plate (5) and the cover plate (4), and the displacement sensor (7) is arranged at the central position of the lower surface of the sliding plate (5).

2. The apparatus for monitoring the thermal expansion stress and deformation of foamed concrete under constraint according to claim 1, characterized in that: the slide way (6) comprises a slide way main body (6-1) and a support (6-2), and the slide way main body (6-1) is vertically and fixedly arranged on the ground through the support (6-2).

3. The apparatus for monitoring the thermal expansion stress and deformation of foamed concrete under constraint according to claim 2, characterized in that: the slide main part (6-1) is of a columnar structure, one end of the sliding plate (5) is fixedly connected with a connecting rod (10), one end of the connecting rod (10) far away from the sliding plate (5) is fixedly connected with a positioning ring (11), the positioning ring (11) is sleeved on the slide main part (6-1) and is limited through a set screw (12).

4. Apparatus for monitoring the thermal expansion stress and deformation of foamed concrete under constraint according to claim 1, 2 or 3, characterized in that: the number of the springs (9) is four.

5. Apparatus for monitoring the thermal expansion stress and deformation of foamed concrete under constraint according to claim 1, 2 or 3, characterized in that: the mould (1) is an iron mould.

6. The apparatus for monitoring the thermal expansion stress and deformation of foamed concrete under constraint according to claim 5, characterized in that: the mould (1) is of a cubic structure or a barrel-shaped structure, cavities are machined in the side portion and the bottom portion of the mould, the heating plate (2) is arranged in the cavity in the bottom portion, and the temperature sensor (3) is arranged in the cavity in the side portion.

7. the apparatus for monitoring the thermal expansion stress and deformation of foamed concrete under constraint according to claim 6, characterized in that: the number of the temperature sensors (3) is two, and the two temperature sensors are symmetrically arranged in cavities at two sides of the die (1).

8. Apparatus for monitoring the thermal expansion stress and deformation of foamed concrete under constraint according to claim 1, 2, 3, 6 or 7, characterized in that: the external part of the mould (1) is provided with a heat insulation layer, and the inner side wall of the mould (1) is provided with a polytetrafluoroethylene layer.

9. The method for monitoring the thermal expansion stress and deformation of the foam concrete under the constraint condition by using the device according to any one of claims 1 to 8, wherein the method comprises the following steps: it comprises the following steps:

Step one, pouring foam concrete (100) into a mould (1), stopping pouring and vibrating to be dense when the pouring height is higher than the top end of the mould (1), and scraping redundant slurry until the upper surface of the foam concrete (100) is flush with the top end of the mould (1);

Secondly, moving the sliding plate (5) up and down to enable the cover plate (4) to be tightly attached to the foam concrete (100), ensuring that the spring (9) is in an original length or a micro-compression state, fixing the position of the sliding plate (5) on the slideway (6), and recording the index x1 of the displacement sensor (7) at the moment;

Setting a target temperature of the temperature control box (8), and starting a switch of the temperature control box (8) to enable the heating sheet (2) to start heating the mold (1);

and step four, reading the index x1 'of the displacement sensor (7) again at the corresponding moment to obtain that the deformation amount of the foam concrete (100) is x'1-x1, and obtaining that the expansion stress of the foam concrete (100) is 4k (x '1-x1) according to Hooke's law and the stiffness coefficient k of the spring (9).

10. The method of claim 9, wherein: and when the pouring height is 3-5 mm higher than the top end of the mold (1), stopping pouring.

Technical Field

The invention relates to a device and a method for monitoring thermal expansion stress and deformation of foam concrete in a constraint state, and belongs to the technical field of civil construction material performance testing.

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. Therefore, the development of the method capable of monitoring the expansion stress and the volume deformation of the confined foam concrete in the steam-curing environment is very important for the popularization and the application of the foam concrete.

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. In addition, at present, no device and method for monitoring expansion stress and deformation of foam concrete under different steam curing systems and in a restrained state exist at home and abroad.

Disclosure of Invention

the invention aims to solve the problems that the expansion stress and deformation of foam concrete can not be measured in real time and in situ in a thermal curing environment and the expansion stress and deformation of the foam concrete can not be measured in different thermal curing environments and in a constraint state in the prior art, and further provides a device and a method for monitoring the thermal expansion stress and deformation of the foam concrete in the constraint state.

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

Device of foam concrete thermal expansion stress and deformation under monitoring restraint state, it includes mould, heating plate, temperature sensor, apron, slide, displacement sensor, temperature control case and a plurality of spring, the mould is the metal material, and its open-top sets up, and foam concrete installs in the mould, and the heating plate is installed in the bottom of mould, and temperature sensor installs the side at the mould, the heating plate with between the temperature control case and temperature sensor with connect through the wire respectively between the temperature control case, the vertical setting of slide is in one side of mould, and slide horizontal arrangement just follows vertical direction sliding connection on the slide, and a plurality of spring equipartitions are between slide and apron, and its upper and lower both ends respectively with slide and apron rigid coupling, and displacement sensor installs and puts at slide lower surface central point.

Further, the slide includes slide main part and support, the slide main part passes through the support is vertical to be set firmly subaerial.

Further, the slide main part is the columnar structure, and the one end fixedly connected with connecting rod of slide keeps away from the one end fixedly connected with holding ring of slide on the connecting rod, the holding ring cover is established it is spacing just through holding screw in the slide main part.

further, the number of springs is four.

further, the mould is an iron mould.

Further, the mould is of a cubic structure or a barrel-shaped 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 temperature sensors are symmetrically arranged in cavities of two side parts of the mold.

Further, the outside of the mould is provided with a heat preservation and insulation layer, and the inner side wall of the mould is provided with a polytetrafluoroethylene layer.

A method for monitoring thermal expansion stress and deformation of foam concrete in a constraint state by adopting the device comprises the following steps:

step one, pouring foam concrete into a mold, stopping pouring and vibrating to be dense when the pouring height is higher than the top end of the mold, and scraping redundant slurry until the upper surface of the foam concrete is flush with the top end of the mold;

Moving the sliding plate up and down to enable the cover plate to be tightly attached to the foam concrete, ensuring that the spring is in an original length or a micro-compression state, fixing the position of the sliding plate on the slideway, and recording the index x1 of the displacement sensor at the moment;

Setting a target temperature of a temperature control box, and starting a switch of the temperature control box to enable a heating sheet to start heating the die;

And step four, reading the index x '1 of the displacement sensor again at the corresponding moment to obtain the deformation of the foam concrete as x'1-x1, and obtaining the expansion stress of the foam concrete as 4k (x '1-x1) according to Hooke's law and the spring stiffness coefficient k.

Further, when the pouring height is 3-5 mm higher than the top end of the mold, pouring is stopped.

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

According to the method, the springs are utilized to restrain the foam concrete, deformation generated when the foam concrete is subjected to thermal expansion can be obtained through spring strain, restraint stress is in direct proportion to deformation of the springs, and then real-time and in-situ monitoring on expansion stress and deformation generated when the restrained foam concrete is heated under different curing systems is achieved.

varying the number of springs and/or the stiffness coefficient may impose varying degrees of constraint on the foam concrete. The displacement change of the cover plate is monitored in real time and in situ by the displacement sensor, so that the expansion stress and deformation of the restrained foam concrete generated by heating under different curing systems are monitored in real time and in situ.

Compared with the prior art, the test device has the advantages of simple structure and working principle, convenient operation process and more accurate test result.

Drawings

FIG. 1 is a schematic perspective view of the present invention;

fig. 2 is a schematic view of the connection between the slide plate and the slide way.

Detailed Description