阅读说明：本技术 一种可表征粘接砂浆湿度变化的墙面结构及其测试方法 (Wall surface structure capable of representing humidity change of bonding mortar and testing method thereof ) 是由 姜伟 顾海涛 高国旗 杨正宏 于 2020-06-18 设计创作，主要内容包括：本发明涉及一种可表征粘接砂浆湿度变化的墙面结构及其测试方法,墙面结构自内而外依次为墙体、砂浆测试层和外保温板,所述砂浆测试层包括多个砂浆层和多个砂浆-碳纳米管层,所述砂浆-碳纳米管层中设有碳纳米管、电流电势测定导线、多组距离测定导线以及与距离测定导线电连接的距离传感器,所述碳纳米管和多组电流电势测定导线均垂直于墙体设置,所述墙体上设有供电流电势测定导线伸出的墙体导线通孔,所述外保温板上设有供电流电势测定导线伸出的外保温板导线通孔。与现有技术相比,本发明可实现准确方便地测定砂浆湿度的变化规律,从而进一步研究砂浆粘结力失效问题。(The invention relates to a wall surface structure capable of representing the humidity change of bonding mortar and a testing method thereof. Compared with the prior art, the invention can accurately and conveniently measure the change rule of the mortar humidity, thereby further researching the problem of failure of the mortar adhesion.)

1. The utility model provides a can characterize wall structure that bonding mortar humidity changes, its characterized in that, wall structure is from interior and be wall body, mortar test layer and outer heated board outward in proper order, mortar test layer includes a plurality of mortar layers and a plurality of mortar-carbon nanotube layer, be equipped with carbon nanotube, multiunit current potential survey wire, multiunit distance survey wire and with the distance measurement distance sensor that the wire electricity is connected in the mortar-carbon nanotube layer, carbon nanotube and multiunit current potential survey the equal perpendicular to wall body setting of wire, be equipped with the wall body wire through-hole that supplies current potential survey wire to stretch out on the wall body, be equipped with the outer heated board wire through-hole that supplies current potential survey wire to stretch out on the outer heated board.

2. The wall structure capable of representing the humidity change of the bonding mortar of claim 1, wherein when no window is arranged on the wall body, the mortar layer and the mortar-carbon nanotube layer are alternately arranged from bottom to top in sequence, and the mortar-carbon nanotube layer is horizontally arranged.

3. The wall structure capable of representing the humidity change of the bonding mortar of claim 1, wherein when a window is arranged on the wall body, the window comprises an upper window frame, a lower window frame and a side window frame arranged between the upper window frame and the lower window frame, the mortar-carbon nanotube layer parallel to the upper window frame is arranged above the upper window frame, the mortar-carbon nanotube layer parallel to the lower window frame is arranged below the lower window frame, and the mortar-carbon nanotube layer parallel to the side window frame is arranged on the side edge of the side window frame.

4. The wall structure capable of representing the humidity change of the bonding mortar of claim 1, wherein the carbon nanotubes are commercially available multiwall carbon nanotubes or self-made carbon nanotube composite materials.

5. The wall surface structure capable of representing the humidity change of the bonding mortar of claim 4, wherein the self-made carbon nanotube composite material is a carbon nanotube/aluminum composite material and is prepared by the following steps:

(i) Adding the cement particles doped with the aluminum simple substance and nickel nitrate hexahydrate into water to obtain a mixed solution, magnetically stirring at the rotating speed of 800-1500rpm for 5-15min, simultaneously dropwise adding a sodium hydroxide solution until the pH value of the mixed solution reaches neutrality, and standing for 36-72h to obtain a precursor solution;

(ii) (ii) placing the precursor solution obtained in the step (i) in a nitrogen atmosphere at the temperature of 100-140 ℃ for drying for 4-8h, and calcining at the temperature of 180-250 ℃ for 2h to obtain a precursor;

(iii) and (3) introducing hydrogen into the precursor obtained in the step (ii) to carry out reduction reaction at the temperature of 400-.

6. A construction method of a wall structure capable of characterizing the humidity change of bonding mortar according to any one of claims 1 to 5, characterized in that the construction method comprises the following steps:

(a) preparing mortar, wherein the mortar comprises pure cement mortar and mixed cement mortar containing carbon nano tubes;

(b) Arranging a wall lead through hole on a wall, pouring and coating pure cement mortar and mixed cement mortar to respectively form a mortar layer and a mortar-carbon nanotube layer, processing the mortar-carbon nanotube layer, and laying a current potential measuring lead, a distance measuring lead and a distance sensor on the mortar-carbon nanotube layer to form a mortar test layer;

(c) and after the pouring, the smearing and the laying are finished, laying an outer insulation board outside the mortar test layer, and arranging an outer insulation board lead through hole on the outer insulation board to obtain the wall surface structure.

7. The method for constructing a wall structure capable of representing the humidity change of the bonding mortar according to claim 6, wherein in the step (b), after the mixed cement mortar is coated once, a magnetic field is applied to make the carbon nanotubes perpendicular to the surface of the wall.

8. The method as claimed in claim 7, wherein the strength of the magnetic field is 2800-3500GS and the time for applying the magnetic field is 5-10 min.

9. A method for testing a wall structure capable of characterizing changes in humidity of a bonding mortar according to any one of claims 1 to 5, characterized in that the method comprises the following steps:

Connecting a current potential measuring lead with a testing device, wherein the testing device comprises an ammeter, a voltmeter and a power supply;

and (II) switching on a power supply, transmitting a current with a set current value to the current potential measuring lead, reading readings of an ammeter, a voltmeter and a distance sensor, and calculating the conductivity of the bonding mortar.

Technical Field

The invention relates to the technical field of buildings, in particular to a wall surface structure capable of representing the humidity change of bonding mortar and a test method thereof.

Background

At the present stage, the phenomenon that the external insulation board and the external hanging decoration of the high-rise building wall fall off frequently occurs in China, and the problem that falling objects injure the current people often occurs, and the problems are traced to the fact that the adhesive force of wall mortar is reduced, and then the external insulation board and the external hanging decoration fall off. Therefore, the problem of mortar adhesion reduction is a problem which must be solved at the present stage.

The mortar is a middle bonding layer of a wall and an outer insulation board, the thickness of the mortar is generally between 10 mm and 20mm, the existing method for testing the mortar bonding force of the wall is complex, the actual mortar bonding force test result is not accurate enough, the mortar bonding force can continuously decline along with time, and the time when the mortar fails can not be accurately judged. The existing method for testing the mortar bonding force still has great defects.

The humidity has great influence on the mortar bonding force, so that whether the mortar bonding force fails can be determined by researching the humidity, and the indirect measurement method has great practical engineering significance. However, the humidity test still has a problem, although the instantaneous humidity condition is easy to obtain, the mortar for bonding the outer heat-insulating plate is wrapped by the heat-insulating plate and cannot be in direct contact with the mortar, the continuous humidity test sensor is high in cost, and the sensor is easy to damage in the integral pouring and plastering process, so that the humidity improvement test still needs to be carried out to solve the actual problem.

Disclosure of Invention

The invention aims to solve the problems and provide a wall surface structure capable of representing the humidity change of bonding mortar and a testing method thereof.

The purpose of the invention is realized by the following technical scheme:

the utility model provides a wall structure of testable bonding mortar humidity change, wall structure is wall body, mortar test layer and outer heated board from inside to outside in proper order, the mortar test layer includes a plurality of mortar layers and a plurality of mortar-carbon nanotube layer, be equipped with carbon nanotube, multiunit current potential survey wire, multiunit distance survey wire and with the distance sensor that the distance survey wire electricity is connected in the mortar-carbon nanotube layer, carbon nanotube and multiunit current potential survey wire all are perpendicular to the wall body surface, be equipped with the wall body wire through-hole that supplies current potential survey wire to stretch out on the wall body, be equipped with the outer heated board wire through-hole that supplies current potential survey wire to stretch out on the outer heated board. Because the quantity and the size of the carbon nano tube are very small, the distance measuring lead is connected out of the distance sensor and is respectively positioned on the plane where the wall body is contacted with the mortar testing layer and the plane where the mortar testing layer is contacted with the outer insulation board, so that the thickness of the mortar testing layer can be accurately measured. The distance sensor can be directly arranged in the mortar-carbon nanotube layer, adopts a DJLK-003A model (the distance sensor of other trademarks sold in the market can realize distance measurement), and is not easy to damage. The conductivity of the bonding mortar and the humidity of the mortar have a relatively stable relationship (the conductivity and the mortar humidity are in a proportional relationship, the higher the humidity of the mortar is, the better the conductivity is), the mortar-carbon nanotube layer is not a pure carbon nanotube layer, but actually is a mortar layer containing carbon nanotubes, and the conductivity and humidity change relationship of the single mortar layer is unstable, so that the carbon nanotubes are added into the mortar to form the mortar-carbon nanotube layer, the mortar with the stable conductivity and humidity change relationship is obtained, and the current potential measuring lead and the distance measuring lead are arranged in the mortar-carbon nanotube layer. The humidity change trend of the mortar is obtained through the accurate test of the conductivity of the bonding mortar, the conductivity is obtained through calculation, and related parameters are obtained through testing.

Three test points are arranged on each horizontal plane in the mortar-carbon nanotube layer, the middle and the left and right edges (10-20 cm away from the edge of the wall body) are provided with a group of current potential measuring leads and a group of distance measuring leads, and the two ends of each current potential measuring lead are respectively positioned on the plane where the wall body is contacted with the mortar test layer and the plane where the mortar test layer is contacted with the outer insulation board (namely, one end of each current potential measuring lead is connected out from the side of the wall body, and the other end of each current potential measuring lead is connected out from the side of the outer insulation board. referring to fig. 1, the distance measuring leads are omitted), so that the electrode distance of the test points is the same as the thickness of the mortar test layer (the thickness refers to the thickness of the mortar test layer, namely, the thickness of the mortar clamped between the outer insulation board and the wall body, it can also be used to input the current of the set value and determine whether the actual current on the current potential measuring wire is the same as the set current, typically the current of the test point and the set current are the same.

Further, when the wall body is not provided with a window, the mortar layer and the mortar-carbon nanotube layer are alternately arranged from bottom to top in sequence, and the mortar-carbon nanotube layer is horizontally arranged.

Further, when a window is arranged on the wall body, the window comprises an upper window frame, a lower window frame and a side window frame arranged between the upper window frame and the lower window frame, wherein a mortar-carbon nanotube layer parallel to the upper window frame is arranged above the upper window frame, a mortar-carbon nanotube layer parallel to the lower window frame is arranged below the lower window frame, and a mortar-carbon nanotube layer parallel to the side window frame is arranged on the side edge of the side window frame.

Further, the carbon nanotubes in the mortar-carbon nanotube layer are single-layer carbon nanotubes.

Furthermore, the carbon nano tube adopts a multi-wall carbon nano tube sold in the market or a self-made carbon nano tube composite material, and the self-made carbon nano tube composite material has a good structure and controllable appearance.

Further, the commercially available multi-walled carbon nano-meterThe inner diameter of the tube is 3-5nm, the outer diameter is 8-15nm, the length is 3-12nm, and the actual density is 2.1g/cm³The specific surface area is more than 233m²The resistivity is 1412 mu omega m, the appearance is black powder, and the multi-wall carbon nano-tube is only taken as an example for illustration and is not limited in particular.

Further, the self-made carbon nanotube composite material is a carbon nanotube/aluminum composite material, and is prepared by the following steps:

(i) Putting the cement particles doped with the aluminum simple substance and nickel nitrate hexahydrate into 1L of distilled water to obtain a mixed solution, stirring for 5-15min by using a magnetic stirrer at the rotating speed of 800-1500rpm, slowly dropwise adding a sodium hydroxide solution until the pH value of the mixed solution reaches neutrality, standing for 36-72h to obtain a precursor solution, wherein the cement particles are only used as carriers and do not participate in the reaction;

(ii) (ii) drying the precursor solution obtained in the step (i) in a nitrogen atmosphere at the temperature of 100-140 ℃ for 4-8h, and calcining at the temperature of 180-250 ℃ for 2h to obtain a precursor;

(iii) and (3) introducing hydrogen into the precursor obtained in the step (ii) to carry out reduction reaction at the temperature of 400-. The self-made carbon nano tube composite material is synthesized by adopting an in-situ synthesis method, firstly adopting a deposition-precipitation method, taking cement particles (aluminum powder doped cement particles, and mainly taking an aluminum base as a catalyst carrier) as a catalyst carrier, and Ni (NO) ₃)₂·6H₂O and NaOH are used as catalyst raw materials to prepare a Ni type catalyst, methane gas is used as a carbon source, and the Ni type catalyst is synthesized on the Ni type catalyst by a chemical vapor deposition method to obtain the self-made carbon nano tube composite material, wherein the inner diameter of the self-made carbon nano tube composite material is 5-10nm, and the outer diameter of the self-made carbon nano tube composite material is 15-23 nm.

Preferably, in step (i), the NaOH solution has a molar concentration of 0.05-0.1mol/LNaOH solution and Ni (NO)₃)₂·6H₂The mass ratio of O is 1: 2.5. Considering that the mass addition amount of the cement particles and the nickel nitrate hexahydrate is not in one order, and the aluminum simple substance is doped on the cement particles, in order to prepare the required carbon nanotube/aluminum composite material, the cement particles are added as much as possible, and the sufficient amount of the aluminum simple substance is ensured.

Preferably, in step (iii), the temperature of the reduction reaction is 450 ℃.

A construction method of the wall surface structure specifically comprises the following steps:

(a) preparing mortar, wherein the mortar comprises pure cement mortar and mixed cement mortar containing carbon nano tubes;

(b) setting a wall lead through hole for the current potential measuring lead to extend out on a wall, pouring and coating pure cement mortar and mixed cement mortar to form a mortar layer and a mortar-carbon nanotube layer respectively, processing the mortar-carbon nanotube layer, laying a current potential measuring lead, a distance measuring lead and a distance sensor on the mortar-carbon nanotube layer, arranging the current potential measuring lead corresponding to the position of the wall lead through hole, and arranging test heads on the current potential measuring leads extending out of the wall lead through hole to form a mortar test layer;

(c) And after pouring, smearing and laying are finished, laying an outer insulation board outside the mortar test layer, arranging outer insulation board lead through holes for the current potential measuring leads to extend out on the outer insulation board, and arranging test heads on the current potential measuring leads extending out of the outer insulation board lead through holes to obtain the wall surface structure.

Further, in the step (a), the pure cement mortar and the mixed cement mortar are prepared by adopting a cementing material, a fine aggregate and water according to a certain proportion, and the proportion can be adjusted according to building requirements and relevant specifications.

Further, in the step (b), after the mixed cement mortar is coated once, a magnetic field is applied to ensure that the carbon nano tubes are vertical to the surface of the wall body.

Furthermore, the magnetic strength of the magnetic field is 2800-3500GS, and the time for applying the magnetic field is 5-10 min.

A testing method of the wall surface structure specifically comprises the following steps:

connecting a current potential measuring lead with a testing device, wherein the testing device comprises an ammeter, a voltmeter and a power supply, and the current potential measuring lead is connected with the ammeter and the power supply in series and is connected with the voltmeter in parallel;

and (II) switching on a power supply, transmitting current with a set current value to the current potential measuring lead, reading readings of an ammeter, a voltmeter and a distance sensor, and calculating the conductivity of the bonding mortar to obtain the humidity change trend of the bonding mortar.

According to the invention, a group of current potential measuring leads and a group of distance measuring leads are arranged on a test point, one end of the test point, which is positioned on a wall body, is marked as a, one end of the test point, which is positioned on an outer insulation board, is marked as a ', a current with a set value is applied to the current potential measuring leads through a power supply, the actual current value can be read from an ammeter and is marked as I, namely the current between a and a ' is also I, at the moment, a potential difference can be generated between a and a ', and the value of the potential difference can be read from a voltmeter and. The formula for calculating the conductivity of the bonding mortar is specifically as follows: sigma is 1/rho (L/R) A (L/(U/I)) A, wherein sigma is the conductivity and can be used for representing the humidity change law of the bonding mortar; rho is resistivity, and since the resistivity (resistance of mortar) of the building mortar changes along with the change of the types of the building mortar in different regions, no specific determined standard parameter exists, and the parameter can be known only by measurement; l is the distance between the internal electrodes (namely the thickness of a mortar test layer clamped between the external insulation board and the wall body), and the thickness of the mortar-carbon nanotube layer at different time intervals (because the service time of the whole wall structure is very long, generally measured in years, and along with the increase of the service time, the thickness of the mortar-carbon nanotube layer has certain change, namely the service time at different time intervals is measured in real time by a distance sensor and a distance measuring lead); a is the electrode area, is the area through the electric current, in the stage of the wall body and external insulation board being in service, its area is obtained by every laying the point and dividing the wall body averagely, the invention is to regard test point as the centre, the side length is 40-100cm square, the concrete numerical value is chosen according to the situation (through the test of the same material mortar block test piece in the laboratory, compare the situation of the test piece of different size, confirm the concrete numerical value finally); and R is U/I is the resistance determined by measuring the voltage drop between two ends of the test point, the current setting is known, and the potential difference value is measured by a specific experiment.

Compared with the prior art, on the premise that the humidity change and the conductivity of the mortar have corresponding relations, the carbon nano tubes with conductivity and stable performance are added into the mortar, so that the relation between the conductivity and the humidity change of the mortar is more stable, and the conductivity change of the mortar is more obvious. Current potential measuring leads, distance measuring leads and a distance sensor are arranged in the mortar-carbon nanotube layer, and the actual change of the conductivity of the mortar at the stage time is tested, so that the change rule of the humidity of the mortar along with the working time is represented, the decline condition of the adhesive force of the mortar is further researched, the failure (falling off) of the adhesive mortar of the outer wall is predicted, and the method is simple and convenient.

Drawings

FIG. 1 is a schematic view of a wall structure;

FIG. 2 is a schematic top view of a wall structure;

FIG. 3 is a schematic view showing the connection between the test apparatus and the current potential measuring wire.

In the figure: 1-a wall body; 2-mortar test layer; 3-an outer insulation board; 4-amperometric potential measurement leads; 5-test head.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.