The Semi-Adiabatic Heat of Hydration Tester is designed to determine the heat of hydration of cement using the semi-adiabatic method. It is developed and manufactured by our company in accordance with the testing requirements of the European standard EN 196-9:2010.

I. Product Description

The semi-adiabatic method for measuring cement heat of hydration involves placing a freshly prepared cement sample into an insulated Dewar flask and monitoring the temperature changes of the sample during the first few days of hydration. After a specified period, the heat of hydration of the cement content in the sample is calculated as the sum of the heat accumulated in the flask during the test and the heat released to the surrounding environment.

During the test, the temperature of the cement mortar sample is compared with the temperature of an inert reference sample placed in a reference calorimetric flask. The amount of heat generated by the cement mortar mainly depends on its properties and may result in a temperature increase ranging from 10°C to 50°C. The heat of hydration is expressed in joules per gram of cement (J/g).

II. Equipment Configuration

The following equipment and accessories are required for testing:

Calorimetric Test Flask: Used to contain the cement mortar sample.

Reference Calorimetric Flask: Filled with mortar that has been mixed at least 12 months previously and is considered inert. If an inert mortar is not available, an aluminum cylinder with a heat capacity equivalent to the combined heat capacity of the mortar container and mortar sample may be used.

Mortar Container: Disposable after each test.

Two Thermometers or Temperature Data Loggers: Used to monitor and record temperature changes during the test.

Planetary Mixer: Complies with the requirements of EN 196-1.

III. Test Conditions

The temperature of the testing room shall be maintained at 20 ± 2°C.

The ambient temperature around the calorimeter shall be maintained between 19°C and 21°C, with fluctuations kept within ±0.5°C.

The reference calorimeter shall be used to measure the ambient temperature.

The air velocity near the calorimeter shall be less than 0.5 m/s.

Heat sources and air vents near the calorimeter shall be eliminated to minimize external thermal interference.

IV. Mortar Sample Composition

Cement: 350 g

Sand: 1,050 g (standardized sand conforming to EN 196-1)

Water (Distilled Water): 175 g

Total Weight: 1,575 g

Multiple tests are commonly conducted simultaneously. In this case, one reference flask can be used for up to six calorimeters.

The reference calorimeter is placed at the center, while the six calorimeters are positioned at equal distances from one another to form a hexagonal arrangement.

V. Calorimetric Flask Features

To obtain reliable test results, the calorimetric flask must be properly calibrated and meet all the requirements of EN 196-9.

For calculations performed according to the standard test procedure, each Langavant calorimetric flask for the semi-adiabatic determination of cement heat of hydration is individually inspected and verified. Each flask is supplied with a nameplate indicating the following information:

Heat Loss Coefficient

Thermal Mass

Dewar Flask Features

Made of borosilicate glass with a hemispherical bottom.

Includes an insulated lid and a rubber disk with a diameter of 85 mm and a thickness of 20 mm. The rubber disk supports the sample container and evenly distributes the load across the glass walls.

Internal Diameter: 95 mm

External Diameter: 120 mm

Depth: 280 mm

Dewar Flask Outer Housing

Designed to accommodate the Dewar flask described above.

Made of 3 mm thick hard aluminum, featuring high rigidity and strength. The wide base provides excellent stability during testing.

An approximately 5 mm air gap is maintained between the Dewar flask and the inner wall of the housing. The flask is supported on a base approximately 50 mm thick.

The upper edge of the glass Dewar flask contacts a 5 mm thick crown-shaped cover, which secures the flask inside the housing.

The crown-shaped locking ring provides a supporting surface for the glass stopper, ensuring reliable sealing.

Both the glass support and crown-shaped locking ring are made of materials with very low thermal conductivity, minimizing heat transfer to the external environment.

The insulated lid consists of three parts:

Lower Section: Inserted into the container to minimize heat loss.

Central Section: Consists of a 120 mm diameter foam rubber disk, which ensures a tight seal for the calorimeter.

Upper Section: Made of a rigid shell with a locking mechanism that compresses the central foam rubber disk, ensuring a secure seal and proper positioning of the Dewar flask lid.

VI. Mortar Sample Container

The mortar sample container is a cylindrical container with a lid, designed to hold the cement mortar sample during testing. It is intended for single use and should be discarded after each test.

The mortar container for the semi-adiabatic determination of cement heat of hydration is made of 0.3 mm thick tinplate and is manufactured by electric welding.

Features:

• Diameter: 80 mm

• Height: 165 mm

• Approximate Capacity: 800 cm³

• Water Vapor Tightness: Impermeable to water vapor at 0.3 bar pressure

The center of the lid is equipped with a cylindrical thermometer holder with a closed bottom. The inner diameter of the holder is slightly larger than the diameter of the thermometer.

The length of the thermometer holder can range from 100 to 120 mm, allowing it to reach the center of the test container.

The mortar container must be completely watertight and moisture-tight. After each test, its watertightness and moisture resistance are verified by weighing the mortar container.

VII. Temperature Probes

The temperature probes used for the semi-adiabatic determination of cement heat of hydration are Pt100 resistance temperature sensors (100 Ω platinum), electrically isolated by a plastic film with very low thermal conductivity.

Each probe is supplied with an ENAC calibration certificate. ENAC accreditation is widely recognized. The calibration is performed using calibrated instruments that are traceable to international temperature standards.

The electronic data acquisition module is equipped with 4 measurement channels for connecting Pt100 probes, allowing up to 3 test calorimetric flasks and 1 reference flask to be connected in accordance with the standard requirements. According to specific testing requirements, an electronic module supporting up to 7 temperature probes can also be provided for the semi-adiabatic heat of hydration test. Please contact our sales team for details.

VIII. Technical Features

PC Communication Interface: RS-232 port

A/D Converter: 16-bit

Linearity: ±0.1% FS

Thermal Drift: ±0.01%/°C FS

Communication Protocol: MODBUS RTU/ASCII

Sampling Rate: 0.5–2 readings/s, depending on the number of channels being read simultaneously

Electrical Isolation: Up to 2000 VAC (3 channels)

R-Line Effect: 0.05%? (Maximum 50?, balanced).

Excitation Current: 0.350 mA.

Data Transmission Rate: Up to 38.4 Kbps.

Maximum Transmission Distance: 1.2 km.

Compliance: EN Standards; Electromagnetic Compatibility (CEE/336/89); Immunity: EN 61000-6-2; Emissions: EN 61000-6-4.

Data acquisition software running on Windows®.

Supports simultaneous measurement of up to 8 channels.

Enables continuous measurement of the heat released by the reference calorimeter and test samples, calculates the heat of hydration of each sample, and displays test result graphs in accordance with the applicable standard.

Fully configurable test parameters, including test conditions and sample information.

Provides real-time temperature/time graphs.

IX. Standard Accessories

A set of 2 independent calorimetric flasks (one for reference), supplied with official calibration certificates.

A set of 2 Pt100 temperature probes with 3 threads, supplied with official calibration certificates.

A set of 50 disposable mortar boxes

Electronic control console equipped with 4 measurement channels and an RS232 output interface, allowing connection of up to 4 calorimetric flasks to a PC (3 for testing samples + 1 for blank reference).

Next-generation PC (dual-core microprocessor or higher), including keyboard, mouse, 20-inch TFT widescreen monitor, Windows® operating system, manuals, and license.

WinLec32 Semi-Adiabatic Heat of Hydration Software License (Test-Lang version), compatible with Windows®, pre-installed on the supplied PC.

Color inkjet printer.

Optional Accessories

Additional insulated calorimetric flask supplied with an official calibration certificate.

A set of 50 disposable mortar containers.

Aluminum Cylinder: Used as a substitute for inert cement mortar as the reference sample.