Estimate In-place Concrete Strength with the Maturity Method
The strength development of a concrete structure is strongly influenced by the temperature and weather conditions at the job site. In construction projects, knowing this strength is crucial as many further decisions depend on it. Decisions such as when to remove the forms, scheduling of post-tensioning operations, when to open bridges and roads for traffic, and determining when to remove the heating measures against cold weather all depend on having the right concrete strength.
In this article, we will explain how you estimate the concrete strength at your job site using the Maturity Method.
How to Estimate Concrete Strength
Before being able to estimate the concrete strength, you will need to perform a maturity calibration to find the relationship between the maturity and the strength development. For monitoring your structure, temperature sensors and data loggers or transmitters are used to measure the temperature inside the concrete and to record this.
1. Determine the monitoring locations
Before pouring the concrete, identify the places in the structure that you want to monitor.
2. Install the temperature sensors
Fasten the temperature sensors with plastic cable ties or strong tape, so the sensor will stay in place at the monitoring location.
3. Connect the data logger or transmitter
Connect the temperature sensors to the data loggers or transmitters and start recording the temperature.
4. Pour the concrete
Once all the sensors have been installed successfully, pour the concrete.
5. Calculate the maturity
Calculate the maturity using one of the maturity functions. This is done by applying the appropriate maturity function to the temperature history that has been recorded by the data logger or transmitter.
6. Determine the in-place strength
To estimate the in-place strength development you will use the maturity curve derived from the maturity calibration.
Once you have calculated the maturity, find the strength by drawing a straight line up until you reach the maturity curve. Then draw a horizontal line to the left to find the related strength.
Example (see illustration): If the maturity of the structure is 10 hours at 20 °C, the correlating in-place strength will be 25 MPa.
Estimating the In-Place Strength with Maturix
In the process above, the last two steps are done manually. However, these are automatically done in Maturix.
Visit our Strength and Maturity Monitoring page to learn more about how Maturix can help you gain real-time insights into your concrete’s temperature and strength development – while saving time and money.