Concrete temperature cracking stress testing machine

SGKL-200KConcrete temperature cracking stress testing machine

Concrete temperature cracking stress testing machineMainly used for concrete temperature induced cracking testing machine, it can simulate the development process of its own temperature stress during the entire process of concrete from pouring to hardening under various temperature control measures, including the process of strain, thermal expansion coefficient, elastic modulus and other parameters developing over time. It can also simulate the real meteorological environment and simulate the temperature stress and cracking mechanism under the influence of natural factors. This instrument can set different temperature and constraint conditions as needed, including insulation, constant temperature, and set temperature rise and fall processes. Through the simulation test of the entire process of concrete cracking, the crack resistance performance of concrete can be evaluated.

Main introduction

The experimental software works in the WINDOWS Chinese environment and has * data processing functions. The experimental conditions and results are automatically saved, and random group experimental data, curves, and reports that comply with relevant national standards are displayed and printed. It is an ideal experimental equipment widely used in industries such as water conservancy, mining, transportation, underground engineering, metallurgy, construction, national defense, colleges and universities, and transportation.

This machine consists of a main unit (including two main and auxiliary specimen molds), a temperature environment regulation system, a measurement and control system, a temperature monitoring system, an electrical drive system, and a computer control and processing system.

Function:

1) A temperature stress test can be conducted in adiabatic temperature rise mode. During the adiabatic temperature rise test, the data collected by the embedded concrete specimen temperature sensor is used as the reference, and the liquid medium tracks the temperature to maintain consistency with the temperature sensor at the core of the specimen, achieving efficient and uniform temperature tracking.

2) A temperature stress test can be conducted using a given simulated temperature curve mode. The temperature guidance (or temperature matching test) mode inputs the existing temperature curve into a computer, and the computer software controls the time template temperature according to the temperature curve, allowing the concrete specimen to progress under this temperature condition and reproduce the concrete's maturation process during the test.

3) The constant temperature test mode is to conduct a concrete specimen cracking test after setting a constant temperature.

4) Based on the above three test temperature modes, concrete specimens were subjected to constraint tests with different degrees of constraint ranging from 0 to 100% to evaluate their crack resistance behavior under different temperature modes and constraint conditions. And parallel tests of concrete specimens under unconstrained conditions can be conducted in the same environment to compare the physical and mechanical properties of concrete with the same mix proportion under different constrained conditions.

5) By providing the temperature and stress state (compression or tension) of concrete specimens, compression/tension creep tests can be conducted to determine the creep characteristics of the tested concrete material, which can be used for the analysis of temperature stress development in concrete.

Main technical indicators:

1. Host form: Double column reaction frame, with two unconstrained specimens subjected to testing simultaneously.

2. Specimen size: 150x150x1500mm (to be designed separately according to actual requirements)

3. Axial loading: 200KN in both tension and compression directions; measurement accuracy not less than ± 0.5% indication; The control accuracy shall not be less than ± 0.5% of the indicated value; The lag time of stress loading is ≤ 3S; when the temperature changes by 30 ℃, the accuracy of stress measurement is not less than ± 1%; Long term work (such as 28 days) maintains the load level within ± 0.05%

4. Loading speed: 0.001-30mm/min

5. Deformation measurement: measuring range: ± 1.2mm; directly measuring the uniform deformation of concrete specimens, accuracy: 0.001mm; deviation not exceeding 10%; Sensors, quartz tube supports, etc. are less than 0.5 μ m/℃ affected by temperature changes

6. Axial loading control method: stress, deformation (displacement) closed-loop control

7. Guarantee of force uniformity: The movable chuck part is equipped with a ball joint that can rotate within a certain range to ensure that the chuck does not transmit bending shear torque; Eccentricity effect: ± 5%/μ m; Torque influence: ± 10%/μ m

8. Loading method: Servo motor reducer ball screw drive

9. Concrete embedded components: The diameter size of sensors (temperature, deformation) and other embedded components is less than 1cm

10. Test piece environmental chamber: made of stainless steel material

11. Test piece temperature control: -20 ℃~80 ℃, measurement accuracy ± 0.1 ℃; Temperature control accuracy higher than 0.5 ℃

12. Heating and cooling rate: temperature control accuracy higher than 0.5 ℃, cooling rate greater than 0.5 ℃/min

13. Heating and cooling medium: 40% ethylene glycol aqueous solution

14. Temperature template: made of stainless steel material;

15. Total power: 15KW, 380V * 50HZ

16. Host size: (length * width * height) 3500 * 1200 * 950mm