Concrete carbonization is a neutralization process. In the presence of water, the product of cement hydration Ca(OH): calcium silicate hydrate CSH reacts with CO2 in the air to make the concrete alkalinity reduce, thereby destroying the alkaline environment where the passive film on the surface of the steel bar relies, causing the steel bar to corrode. The concrete structure has been in a natural carbonization environment for a long time, and the research on the carbonization performance of concrete is usually carried out in the laboratory accelerated carbonization environment. There are differences in the CO2 concentration, temperature and humidity.
Carbonization tests in Europe and the United States are mainly divided into two types: Natural Carbonization Tests and Accelerated Carbonization Tests. The former is like the CEN (European Standards Committee) standard, the test condition is 350 ± 50 ppm CO2, the temperature is 20 ± 2℃, and the humidity is 65 ± 5%. It can be seen that it is equivalent to the concentration of CO2 in the atmosphere. There are many test methods for rapid carbonization of concrete, and there is no uniform standard. Example, the UK uses a 4% CO2 concentration, a temperature of 20±2°C, and a humidity of 55±5%.
|Equipment Model: WEW-ACC-0420L-01||Temperature Range: 15℃ ~ 30℃|
|Internal Dimensions: 740×520×1100 mm||External Dimensions: 120×65×168 mm|
|Temperature Uniformity: 0.5℃ ~ 2℃||Heating Power: 800W|
|Concrete Samples: 100*100*400mm, 24 Pieces||Cooling Power: 230W|
|Humidification Power: 50W||Output Mode : Pulse Solid State Relay ( PID + SSR )|
|Temp Sensor: Dual Platinum Resistance PT100Ω/MV||Heating Speed: 3℃ ~ 5℃/min|
|CO2 Sensor: Imported Photoelectric Sensor||Cooling Rate: 0.7 ~ 1℃/min|
|Heating System: Nickel-chromium Alloy Electric||Control Humidity: 50% ~ 95%|
|CO2 Concentration: 0% ~20%||Timing Function: 0.1～999 (S, M, H)|
|Humidity Accuracy: ± 3%||Refrigerating System: Tecumseh (France) 2.5P|
|CO2 Concentration Tolerance: ±1%||Power Supply: AC 220V, 50/60Hz, 1 Ph|
The traditional method of measuring the depth of carbonization is to use the phenolphthalein indicator method. The carbonization of the substance inside is determined by the principle that phenolphthalein turns red in contact with alkali, but it is difficult to judge the phenolphthalein in some carbonized areas. This is the real reason why you need to choose an carbonation chamber for rapid carbonation test.
Furthermore, There are many repair and maintenance projects for concrete structures in Europe, and some test methods for evaluating the anti-carbonization performance of concrete repair materials have emerged, such as the European prEN13295 (test method for products and systems for protecting and repairing concrete structures-determination of anti-carbonization performance ), The CO2 concentration used in this method is 1%. Finland’s NT BUILD 357 (Concrete, repair material and protective coating anti-carbonization test), the CO2 concentration used in this method is 3%.
|The electrical control is through the microcomputer controller. Automatically control according to the set temperature, humidity and CO2 concentration to ensure constant temperature, humidity and CO2 concentration in the test room.||Electronic and Circuit Part|
|The outer case plate of the carbonation test chamber’s body is made of cold-rolled steel plate, electrostatic powder sprayed, the inner tank is made of high-quality stainless steel plate, and the thermal insulation layer is made of polyurethane integral foaming.||Internal Room Structure|
|The carbonation chamber’s metal shelf is made of plastic frame. The test area has good thermal insulation, airtightness, and corrosion resistance.|
|This type of temperature sensor uses a PT100 temperature sensor. It is a sensor type commonly used in electronic temperature sensors currently used; it has the characteristics of high accuracy and good linearity.||Temp Monitor System|
|When the sensor detects that the temperature in the box is lower than the lower limit of the control value, the controller sends a command and the heating element starts to work, otherwise, when the temperature is higher than the upper limit of the control value, the controller sends a command to the compressor to work.|
|When the temperature in the room reaches the set control value, the heating element or compressor stops working, So as to achieve the goal of constant temperature in the test room.|
|Using evaporative moisture absorption dehumidification, when the humidity in the box is higher than the upper limit of the control value, the instrument outputs signal instructions to work, and the compressor is started for dehumidification.||Humidity Control System|
|When the humidity in the room is lower than the lower limit of the control value, the meter outputs a command and the humidifier starts to spray wet. Note: Please fill the humidifier with distilled water to ensure the working life of the sensor.|
|The carbon dioxide sensor adopts imported infrared sensitive sensor. By emitting a certain frequency of infrared rays and the infrared rays of this frequency are easily absorbed by carbon dioxide gas, and then determine the concentration of carbon dioxide based on the intensity of the reflection.||C02 Control System|
|At the same time, the sensor can also detect whether the sensor has data bias due to other reasons. Shift, automatic software compensation, no special circumstances generally do not need to be corrected.|
|The door of the concrete carbonation test chamber is equipped with a transparent glass observation window. It is more convenient for users to observe the changes of the test piece.||Doors, Sight Window|
|The test process realizes automatic control, and the temperature, humidity and CO2 concentration in the box are displayed intuitively and digitally.|
The CO2 concentration used in the above two test methods is far lower than the 20% concentration specified in my country’s rapid law. Concrete and accelerated carbonation testing can be seen that Europe tends to adopt normal pressure, low-concentration rapid test methods. A similar measurement method is Japan’s JIS A1152-2002 (measurement method for the depth of concrete carbonization). However, There are also research institutions in the United States and Canada that use 100% CO2 for rapid tests. In addition, there has also been a test method for evaluating the resistance of concrete to carbonation by using the resistance of concrete.
The accelerated carbonation chamber is perfect for determining the life of concretes / building materials under a constant temperature, CO2 concentration, and humidity. ISO 1920–12: 2015 -Part 12, as a testing standard for concrete materials in the construction industry, has been widely used by a large number of laboratories and testing institutions. If you are looking for a concrete carbonation test chamber manufacturer and supplier from China, Please contact us in time. We can provide you with very timely and appropriate services.