Temperature

Temperature monitoring of concrete involves the use of wired or wireless concrete sensors to measure and record the temperature inside concrete structures during curing, either for bulk temperature monitoring or strength calculations.

Test Systems

Bulk Temperature Measurements

The most common application for temperature sensors in fresh concrete is to monitor the absolute maximum temperature of the concrete during curing / hydration and the relative temperature differentials between the centre and external surfaces.

Traditionally concrete thermocouples and simple data loggers may have been used, but self contained temperature sensors are now common for on site applications where the reliability and security of data is essential.  

Concrete Maturity

​The Concrete maturity method is based on the American standard ASTM C1074 and is used to estimate the early age strength of in situ concrete using a calculated index value that is based on how long the concrete has been in place on site and what the measured concrete temperature is during that time on site.

A calibration curve for each mix design used in a project or in a precast yard allows the measured maturity index to convert to an Mpa early age compressive strength value, reducing the need for early age cylinder breaks or other means to establish strength for lifting precast or to remove formwork or traffic concrete on site.

Hot Box Temperature Measurements

The Hot Box method is used as input data for the prediction of in situ concrete temperature rise when modelling a concrete pour. It is intended to approach the outcome of a true Adiabatic Temperature measurement process for a concrete mix.

Approximated or true Adiabatic Temperature of concrete mixes is used to understand its performance in bulk pours to model potential thermal cracking, and may also be used to understand curing properties.

A 1 m square block of concrete made to the same recipe as an in situ mix is cast in an insulated box and temperature monitored during its curing.

PCTE's Hot Box Data Logging solutions simplify the collection of temperature measurements from this setup, offering a package with temperature sensors, data logger and the option of strain gauges if required. No programming is required to setup the simple data logger.