Concrete-pressure-strength-detection-method

Concrete pressure strength detection method

1. Rebounder or Schmitt Hammer (ASTM C805)

Method: The hammer is activated by a spring release mechanism, which presses the plunger and presses it into the concrete surface. The rebound distance from the hammer to the concrete surface is in the range of 10 to 100. The measurement results are then associated with the strength of the concrete.

Pros: Relatively easy to use and can be done directly in the field.

Cons: To ensure accurate measurementresults, pre-calibrated concrete samples are required.

Different states of the surface and the presence of rebar under large aggregates or test sites can affect the test results.

2. Penetration test (ASTM C803)

Methods: When carrying out a penetration test, a pin or probe is drilled into the concrete surface with a special device. The strength and depth of drilling required to drill into a concrete surface are related to the strength of the poured concrete.

Pros: Relatively easy to use and can be done directly in the field.

Cons : The data are greatly influenced by conditions such as surface state, template type, and aggregate used. Accurate strength measurements require multiple sampling of concrete samples for early calibration.

3. Ultrasonic pulsation detection (ASTM C597)

Method: This method is used to judge the velocity of the vibration energy pulsation in the ground floor. The ease with which this energy penetrates the floor plate reflects the results of the concrete’s ability to elastic, resist deformation or stress, and density. The data is then associated with the strength of the concrete slab.

Pros: This is a non-destructive testing method and can also be used to detect defects such as cracking or honeycomb holes inside concrete.

Cons: The method is seriously affected by the enhancement method, the moisture in the aggregate and the concrete material. Multiple samples and calibrations are also required to obtain accurate test results.

4. Pull-up test (ASTM C900)

Method: The main principle of this method is to pull the metal rod, which is poured inside or installed afterwards, out of the concrete. The cone after pulling out and the amount of force required to pull out from the concrete are related to the strength of the pressure.

Pros: Easy to use, can be done in both old and new building structures.

Cons: This detection can cause the concrete to break or damage. To obtain accurate test results, a large number of test samples need to be selected at different locations on the floor plate.

5. Drill core method (ASTM C42)

Method: The drill core method is used to extract solidified concrete sample blocks from the floor plate. These samples are then compressed in the machine to monitor the strength of their concrete.

Pros: These samples are more accurate than field solidification samples because the concrete of strength is tested by actual heat and solidified on site.

Cons: This is a destructive detection method that requires the destruction of the structural integrity of the concrete slab. The position of the core needs to be patched after the fact.

The strength data must be obtained by the lab.

6. Poured concrete cylinder detection method (ASTM C873)

Method: The cylindrical mold is placed in the position of the pouring area. Fresh concrete is discharged directly into these molds, which are retained in the floor board. After the floor plate solidifies, remove the specimens and pressurize them to detect their strength.

Pros: This method is considered to be more accurate than on-site cured specimens because the concrete undergoes the same solidification process and conditions as the site floor plate;

Cons: This is a destructive detection method that requires the destruction of the structural integrity of the concrete slab. The hole position left after the specimen is removed needs to be repaired afterwards. The strength data must be obtained by the lab.

7. Wireless Maturity Sensor (ASTM C1074)

Methods: The principle of this method is based on the direct relation of concrete strength and its hydration temperature history. Before starting pouring, the wireless sensor is placed in a concrete template and secured on the rebar. The sensor receives temperature data and uploads it to any smart device APP with a wireless connection. According to the maturity calculation formula of the setting number in the APP, the collected information is used to calculate the pressure strength of the concrete element at the current position.

Pros: Anti-pressure strength data is fed back in real time and updated every 15 minutes. At the same time, because the sensor is embedded inside the template, the data accuracy and reliability are also ideal, i.e. the curing data collected is consistent with the in situ concrete element. This also means that you don’t have to spend time waiting for a third-party lab to provide the test results.

Cons: Each batch of mating concrete needs to create a maturity curve using a test method of a collapse dwelling barrel and complete a one-time calibration.