The Federal Highway Administration (FHWA)
Mobile Concrete Technology Center (MCTC)
offers a ONE-PAGEÂ TECH TRANSFER DOCUMENT
that provides some observations on a simple,
inexpensive field testing concrete &
cementitious material hydration.
âHydration creates exothermic chemical reactions, which can be monitored by measuring the total heat generated over time. “Monitoring Concrete Consistency using Semi-Adiabatic Calorimetry” descibes a test method that can monitor batch-to-batch consistency of concrete mixtures. The test works by casting a standard concrete cylinder, then placing it in the calorimenter, recording the time-temperature curve (or heat signature), then comparing the curves of other samples from the same mixture.
Calorimetry measures the heat generated from the early hydration reactions of cementitious materials. The heat outflow tracks the hydration reactions of cement, which gives visibility into the behavior of concrete or mortar in a way that a simple set time or compressive strength test could not. The timing and shape of the temperature curve obtained through calorimetry is an indicator of relative performance of cementitious mixes.
Calorimeters are described as effective tools during mix design to determine potential material incompatibility or optimal dosages/sequence of addition of admixtures. They can be used to determine setting times and saw cut times in lieu of physical testing. Semi-adiabatic calorimeters can also be used as a quality control tool to monitor variations in the sources, quantities, and chemistry of portland cement, supplementary cementitious materials, and chemical admixtures during concrete production. To view a copy of the document, please click on image to right. To download a copy of the document, please go to: http://www.acpa.org/wp-content/uploads/2019/10/Calorimetry.pdf
For the FHWA website for âMonitoring Concrete Consistency using Semi-Adiabatic Calorimetryâ, please go to: https://www.fhwa.dot.gov/pavement/concrete/field.cfm