CN211785018U

CN211785018U - Concrete durability test box under combined action of carbonization and alkali aggregate reaction

Info

Publication number: CN211785018U
Application number: CN201920884154.XU
Authority: CN
Inventors: 张茂花; 张文悦; 孙彦宇
Original assignee: Northeast Forestry University
Current assignee: Northeast Forestry University
Priority date: 2019-06-12
Filing date: 2019-06-12
Publication date: 2020-10-27
Anticipated expiration: 2029-06-12

Abstract

The invention discloses a durability test box device under the combined action of concrete carbonization and alkali aggregate reaction, and provides an experimental device with simple structure, convenient operation and low price for a durability test under the combined action of carbonization and alkali aggregate reaction. It comprises a main body iron plate box, a constant temperature system, a constant humidity system and CO₂And (4) dispersing the system. The testing device has simple structure and low manufacturing cost, can ensure the constancy of the temperature and the humidity required by the test, and CO₂The concentration is stable. Separate carbonation reaction durability tests and alkali aggregate reaction durability tests may also be conducted.

Description

Concrete durability test box under combined action of carbonization and alkali aggregate reaction

Technical Field

The invention relates to a concrete durability test box under the combined action of carbonization and alkali-aggregate reaction.

Background

Dense pedestrian flow in subway station, relatively closed space and CO in tunnel₂And the water vapor content is higher, so that the concrete in the subway tunnel lining is easier to carbonize than other building concrete. The occurrence of carbonization causes the PH of the concrete to decrease, which in turn causes corrosion of the reinforcing steel bars, resulting in durability of the concrete. Alkali-aggregate reactions are a serious concrete durability problem, the occurrence of which is both difficult to find and difficult to repair. Because the alkali aggregate reacts on tiny cracks generated in the concrete, the alkali aggregate does not generate cracksOnly the durability of the concrete is reduced, and other corrosive effects on the concrete are accelerated. Therefore, the reduction of the durability of concrete caused by the combined action of carbonization and alkali-aggregate reaction seriously affects the normal use of the subway tunnel against the environmental conditions inside the subway tunnel concrete. At present, both carbonization and alkali-aggregate reaction have relatively mature technical specifications and test equipment at home and abroad. However, the study of concrete durability tests under the combined action of carbonation and alkali-aggregate reaction lacks both clear specifications and corresponding test equipment.

The invention content is as follows:

the technical problem is as follows: in order to fill the blank of concrete durability research under the combined action of carbonization and alkali aggregate reaction, the invention provides concrete durability test equipment with simple structure, easy operation and low cost.

The technical scheme is as follows: the invention relates to a concrete carbonic acid erosion test box, which comprises a main body iron plate box, a constant temperature system, a constant humidity system and CO₂And (4) dispersing the system.

A diaphragm plate is welded in the iron plate box to divide the iron plate box into a test box A and a test box B.

Holes are respectively formed in the side wall a of the test box A and the top surface B of the test box B, and a U-shaped heating pipe (2) and a temperature sensor (3) are fixed at the holes; diagonal terminal c on top surface of test box B₁And end point c₂At the position where the hole is opened, the end point c₁Is connected with CO through a section of rubber pipe₂The steel cylinder (5) is an air inlet hole, and the end point c₂The other section of rubber hose is extended into the air outlet hole to be used as an air outlet hole, and the rubber pipe at the air outlet hole is clamped by a water stop clamp; a hole d on the side wall of the test box B close to the bottom end is connected with a humidifier (8) through a plastic hose; the top surface e of the test box B is provided with a hole, and a humidity sensor (10) is fixed at the hole.

The constant temperature system is composed of a constant temperature box (1), a U-shaped heating pipe (2) and a temperature sensor (3), wherein the constant temperature box (1) and the U-shaped heating pipe (2) which are fixed on a test box A are connected with the temperature sensor (3) which is fixed on a test box B through a lead (4). During the test, the temperature sensor (3) transmits a new temperature signal in the test box B to the thermostat (1), and the thermostat (1) controls the U-shaped heating pipe (2) in the test box B to work to adjust the water temperature in the test box A, so that the aim of maintaining the temperature in the test box B in a temperature range required by the test is fulfilled.

The constant humidity system is composed of a humidifier (8), a humidity switch socket (9) and a humidity sensor (10), the humidity switch socket (9) and the humidifier (8) are connected through a lead (4), and the humidifier stretches into the test box B through a plastic hose (7). During testing, the humidity sensor (10) transmits a humidity signal to the humidity switch socket (9) to control the humidifier (8) to work, so that the humidity in the test box B is maintained in a humidity range required by the test.

The CO is₂The dispersion system includes a test chamber B, CO₂A steel cylinder (5) and a rubber tube (6). CO 2₂The steel cylinder passes through the rubber tube and the end point c of the air inlet of the test box B₁Is communicated with the other part, and another section of the rubber pipe is arranged at the end point c of the air outlet₂The part extends into the iron plate box and is clamped tightly by a water stop clamp. During the test, CO was turned on₂Cylinder valve for CO₂Slowly introducing the gas into the test chamber to make CO₂The required concentration of the gas reaches the concentration required by the test; after the test is started, the specific length type CO is used periodically₂CO in gas rapid detection tube detection test box₂The concentration of CO in the experiment box is adjusted through the air inlet hole and the air outlet hole₂And (4) concentration.

Compared with the existing experimental device, the invention has the beneficial effects that:

the invention is suitable for simulating the durability of the subway concrete under the combined action of carbonization and alkali-aggregate reaction, and passes through a constant temperature system, a constant humidity system and CO₂The synergistic effect of the dispersing system enables the temperature, the humidity and the CO in the test chamber to be₂The concentration was stabilized within the range required for the test.

The invention provides a durability test device for concrete under combined action of carbonization and alkali aggregate reaction, and fills the blank of the related field. It is characterized in that: the structure is simple, the price is low, the operation is easy, the disassembly is convenient, and the device can be repeatedly used; welding a diaphragm plate in the main body iron plate box according to requirements to divide the main body iron plate box into a test box A and a test box B, andafter holes with different sizes are drilled on the two test boxes according to requirements, devices required by the constant temperature system can be fixed only by simple operation; the elements between the constant humidities are connected only by a lead (4) and are connected with the test box B through a plastic hose (7); CO 2₂The dispersion system only needs two sections of rubber pipes (6) to extend into the test box.

The invention is not only suitable for the durability test of concrete under the reaction action of carbonization and alkali aggregate, but also can be used for respectively carrying out the durability test of carbonization and the durability test of alkali aggregate reaction. The internal space of the traditional carbonization device and the alkali aggregate reaction experimental device is relatively small, and the test with a large number of concrete test blocks needs to be carried out in batches, so that resources and time are wasted. Because the size of this proof box can be mastered in a flexible way, consequently, see that can put into wherein the concrete test block of a great quantity simultaneously, experimental cost and time have been practiced thrift in the experiment.

Drawings

FIG. 1 is a schematic diagram of the present invention.

Fig. 2 is a schematic view of the thermostatic system of the present invention.

Fig. 3 is a schematic view of the constant humidity system of the present invention.

FIG. 4 is a CO of the present invention₂Schematic diagram of a dispersion system.

Detailed Description

The technical solution of the present invention is further explained with reference to the drawings and the embodiments.

The invention comprises an iron plate box, a constant temperature system, a constant humidity system and CO₂And (4) dispersing the system.

Referring to fig. 1 and 2, three round holes are drilled in a position a of a test box A and a position B of a test box B respectively and used for fixing a U-shaped heating pipe (2) and a temperature sensor (3) respectively, and then the three round holes are connected with a constant temperature box (1) through a lead (4) to form a constant temperature system of the test box.

II, referring to fig. 1 and 3, holes are formed in the top surface e and the side wall of the test box B close to the bottom end d, the humidity sensor (10) extends into the test box B from the position e and is fixed well, the humidity sensor (10), the humidity switch socket (9) and the humidifier (8) are connected through a lead (4), and meanwhile, the plastic hose (7) for the holes in the position d is connected with the humidifier (8) to form a constant humidity system of the test box.

III, see FIGS. 1 and 4, at the top end c of test chamber B₁And end point c₂Drilling holes respectively, taking two sections of rubber pipes (6), connecting one section with CO₂A steel cylinder (5) and an end point c₁Is extended into the test box B, and the other section is formed by an end point c₂The part extends into the test box B and is clamped by a water stop clamp; formation of CO₂And (4) dispersing the system.

Example 1: concrete durability test (simulating durability of subway tunnel concrete) under combined action of carbonization and alkali aggregate reaction

Step 1: the size of the required test box is determined according to the size and the number of the concrete test blocks required by the test, an iron plate box with the length, the width and the height of 1300 x 1100mm is welded by the iron plate, the side wall of 1300mm is measured by 300mm, an iron plate with the size of 1100 x 1100mm is welded at the position, and the test is divided into a test box A and a test box B. The test chamber A is filled with water for adjusting the temperature in the test chamber B, and the test chamber B is used for a concrete durability test.

Step 2: putting a prepared square pipe iron frame into a test box, putting a layer of concrete on each square pipe iron frame, and putting 80 concrete test blocks in 4 layers.

And step 3: referring to the specific embodiments I, II and III, a constant temperature system, a constant humidity system and CO are respectively arranged₂Finishing the assembly of the dispersion system; adjusting a thermostat to reach a preset temperature and maintain the temperature to be stable according to the proper temperature of the alkali aggregate reaction; setting the humidity range of the humidity switch socket to enable the set humidity to reach the humidity required by the test; specific length type CO for timing₂The gas rapid detection tube measures the temperature in the test chamber and passes through CO₂CO in decentralized system regulation test box₂The concentration reaches the concentration range required by the test.

And 4, step 4: and after the specified age is reached, taking out the concrete test block, collecting test data, and repeating the operation steps until the final test is finished.

Example 2: durability test of concrete carbonization reaction (different temperature, humidity and CO can be studied₂Concentration pairInfluence of carbonization reaction)

Step 2: the concrete test blocks are prepared by adopting low-alkali cement, the alkali aggregate reaction is limited, a prepared square pipe iron frame is placed into a test box, one layer of concrete is placed in each square pipe iron frame, and 80 concrete test blocks are placed in 4 layers.

And step 3: referring to the specific embodiments I, II and III, a constant temperature system, a constant humidity system and CO are respectively arranged₂Finishing the assembly of the dispersion system; adjusting a thermostat to reach a preset temperature and keeping the temperature stable according to the temperature required by the test; setting the humidity range of the humidity switch socket to enable the set humidity to reach the humidity required by the test; specific length type CO for timing₂The gas rapid detection tube measures the temperature in the test chamber and passes through CO₂CO in decentralized system regulation test box₂The concentration reaches the concentration range required by the test.

Example 3: concrete alkali aggregate reaction durability test (the influence of different temperatures on the alkali aggregate reaction can be studied)

Step 1: the size of the required test box is determined according to the size and the number of the concrete test blocks required by the test, an iron plate box with the length, the width and the height of 1300 x 1100mm is welded by the iron plate, the side wall of 1300mm is measured by 300mm, an iron plate with the size of 1100 x 1100mm is welded at the position, and the test is divided into a test box A and a test box B. The test box A is filled with water and used for adjusting the temperature in the test box B, and the test box B is used for the concrete alkali aggregate reaction durability test.

And step 3: respectively assembling the constant temperature system and the constant humidity system according to the specific embodiments I and II; adjusting a thermostat to reach a preset temperature and maintain the temperature to be stable according to the proper temperature of the alkali aggregate reaction; and setting the humidity range of the humidity switch socket to enable the set humidity to reach the humidity required by the test.

The present invention is not limited to the above embodiments, and any simple modification, equivalent change and modification made by the technical essence of the present invention by those skilled in the art can be made without departing from the scope of the present invention.

Claims

1. A concrete durability test box under combined action of carbonization and alkali aggregate reaction is characterized in that: it comprises an iron plate box, a thermostat (1), a U-shaped heating pipe (2), a temperature sensor (3) and CO₂A steel cylinder (5), a humidifier (8), a humidity switch socket (9), a humidity sensor (10), a longer CO₂A gas detection tube and an extruded sheet; an iron plate is welded in the iron plate box, and the iron plate box is divided into a test box A and a test box B; a hole is formed in the side wall a of the test box A and used for fixing the U-shaped heating pipe (2), a hole is formed in the center B of the top surface of the test box B, and the temperature sensor (3) is fixed in the hole; a hole is formed at the position d of the test box B, and a humidifier (8) is connected through a plastic hose (7); the center e of the top surface of the test box B is provided with an opening for fixing a humidity sensor (10); the diagonal terminal c on the top surface of the test box B₁And end point c₂Respectively perforating, taking two sections of rubber pipes (6), connecting one section with CO₂The steel cylinder (5) is formed by an end point c₁Extending into the test chamber B as an air inlet, and the other section is formed by an end point c₂Also extends into a test box BThe other part is clamped by a water stop clamp to be used as an air outlet.

2. The concrete durability test chamber according to claim 1, wherein: a transverse partition plate is welded in the iron plate box, the iron plate box is divided into two parts, the part with the smaller volume is a test box A, the test box A is used as a water tank and filled with water, and the temperature of the water in the test box A is controlled through a constant temperature system; the larger part is test box B for the concrete durability test.

3. The concrete durability test chamber according to claim 1, wherein: the constant temperature box (1), the U-shaped heating pipe (2) and the temperature sensor (3) are connected through a lead (4) to form a constant temperature system; the temperature sensor (3) transmits a temperature signal to the thermostat (1) to control the U-shaped heating pipe (2) to work, the water temperature in the test box A is adjusted, and then the temperature in the test box B is adjusted to be constant at the temperature required by the test.

4. The concrete durability test chamber according to claim 1, wherein: the humidifier (8), the humidity switch socket (9) and the humidity sensor (10) are connected to form a constant humidity system; the humidity sensor (10) transmits a humidity signal in the test box B to the humidity switch socket (9) to control the humidifier (8) to work, and the humidity in the test box B is maintained within a test humidity range.

5. The concrete durability test chamber according to claim 1, wherein: two sections of rubber pipes (6), one section is connected with CO₂The steel cylinder (5) and the air inlet hole extend into the test box B, the other section of the steel cylinder extends into the test box B through the air outlet hole, and the part outside the test box is clamped by a water stop clamp; by CO₂CO in steel cylinder and water stop clamp adjusting test box B₂Concentration, specific length type CO₂Gas detection tube for detecting CO in test box B₂Concentration of CO in test cell B₂The concentration reaches the concentration value required by the test, thereby forming CO₂And (4) dispersing the system.

6. The concrete durability test chamber according to claim 1, wherein: sealing the test box A with an adhesive tape to prevent moisture from evaporating to shadow the humidity in the test box B; meanwhile, the opening of the test box B and the contact part of the top cover and the side wall of the test box B are sealed by adhesive tapes, so that the test box B is prevented from humidity and gas exchange with the outside air.

7. The concrete durability test chamber according to claim 1, wherein: six faces of the iron plate box are wrapped by extruded sheets, so that heat exchange between the iron plate box and the external environment is reduced.