Cement hydration heat test apparatus (solution heat method)

Model:SN2025-ACC004

I.Description:

This cement hydration heat testing apparatus (solution heat method) is designed and manufactured according to the relevant requirements of the solution heat method (alternative method) in the national standard GB/T 12959 "Determination of Heat of Hydration of Cement", and fully complies with the technical specifications of the new version GB/T 12959-2024 "Determination of Heat of Hydration of Cement". At the same time, this equipment meets the international standard requirements of ISO 29582-1:2009 and can be used for export and various international projects. It is suitable for determining the heat of hydration of medium-heat Portland cement, low-heat slag Portland cement, ordinary Portland cement, slag Portland cement, pozzolanic Portland cement, fly ash Portland cement, etc., at any hydration age. This instrument can also be used for other cement types when the solubility heat method is specified for determining the heat of hydration.

II. Technical Parameters of SN2025-ACC004 Cement Hydration Heat Tester

Water bath temperature: 20℃±0.1℃

Vacuum bottle volume: Approximately 650ml

Cooling rate (after being filled with water 5℃ higher than room temperature and left to stand for 30 minutes): ≤0.001℃/min ℃

Acid Stirring Rod Speed: 400~500rpm

Power Supply: 2500W/ AC220V/50Hz

Beckman Differential Thermometer

Difference Range: 5~6℃

Graduation Value: 0.01℃

Instrument Dimensions (Length × Width × Height mm)

Main Unit: 800×500×760

Thermostatic Unit: 730×420×500

Net Weight: 130kg

III. Structural Description of the SN2025-ACC004 Cement Hydration Heat Tester

This product mainly consists of the following parts:

1) Thermostatic Water Bath:

The thermostatic water bath is a container approximately 30cm deep with a volume of about 60 liters. It contains a base for holding the inner test cylinder, an overflow pipe to control the water level, and a drain pipe with a drain valve at the drain pipe opening.

The constant-temperature water bath is housed within the casing and connected to an external constant-temperature unit via a water pump and piping. After the operating temperature is pre-set, when the water temperature in the bath exceeds 20°C, the exchange of water between the inside and outside of the bath maintains a constant temperature. The external constant-temperature unit also supplies water to the motor cooling jacket. When the water temperature drops below 20°C, the heating element activates to raise the water temperature. The bottom of the bath has a high-performance insulation layer, and the top is fitted with a cover.

2) Inner Test Cylinder:

The inner test cylinder consists of a cylinder body, a cover, a foam insulation jacket, a vacuum bottle, a Beckman differential thermometer, and a feeding funnel. The inner test cylinder can move up and down along a groove on the cylinder base. When it reaches the lowest position, rotating it by an angle will fix it in that position. There are three positioning blocks on the top of the cylinder base for precise adjustment of the inner test cylinder's position (this is pre-calibrated at the factory and generally does not require modification). The cylinder body, cover, and base are all made of stainless steel. The cylinder contains an insulating sleeve and a vacuum bottle. The vacuum bottle has an acid-resistant liner to hold the experimental acid solution; the liner is reusable after cleaning. The vacuum bottle and liner are sealed and insulated with a cork stopper fixed under the cylinder cap. The stopper has three holes for inserting a Beckman thermometer, an acid stirring rod, and a feeding funnel, respectively. An O-ring seal is used between the cylinder and the cap; tightening the wing nut on the cap prevents water from the water tank from seeping into the cylinder.

3) Power Unit:

Each stirring head in the power unit consists of a motor, motor sleeve, crossbeam, large and small pulleys, cooling pipes, water tank stirring rod, acid stirring rod, main shaft, chuck, and synchronous belt.

The motor sleeve is fixed to the cover plate of the water tank section. The motor is mounted inside the motor sleeve cavity, with a small pulley on the upper part. The crossbeam is fitted around the outer ring of the motor sleeve and can rotate around the motor axis to adjust the position of the stirring rod. After adjustment, rotating the locking handle on the crossbeam locks the crossbeam in place. The other end of the crossbeam houses a bearing and a spindle sleeve within its main shaft hole. Inside the spindle sleeve is a vertically movable spindle. Adjusting the fixing screws on the spindle allows for vertical movement of the spindle, thus adjusting the height of the stirring rod within the vacuum flask. A chuck is mounted at the lower end of the spindle, clamping the acid stirring rod through the hole in the flask's cap. A large pulley, driven by a synchronous belt, is mounted at the upper end of the spindle sleeve. Cooling pipes surround the motor for cooling.

4) Control Section

The control section consists of a controller, a temperature sensor, and a heating element. The heating element is installed in a constant-temperature water bath, and the temperature sensor is inserted into a hole in the water bath cover. The controller displays the temperature, pre-adjusted to 20℃±0.1℃ at the factory, generally requiring no further adjustment by the user. The controller includes switches for controlling the rotation of the left and right water bath stirring rods and the acid stirring rod, which can be switched on and off as needed.

IV. Installation and Use of the SN2025-ACC004 Cement Hydration Heat Tester

The instrument must be placed in a constant temperature chamber at 20±1℃ on a level workbench with a 4-5mm rubber pad underneath.

Connect the inlet and outlet pipes on the rear of the instrument to the external temperature control unit using a flexible rubber or plastic tube. Connect the overflow pipe and drain pipe to the sewer. Close the drain valve. Check that all pipes are clear. Add water to the tank until water flows out of the overflow pipe.

At the start of the test, raise the inner test cylinder from the tank to a position above the water surface and secure it. Open the inner cylinder cover, place the vacuum bottle, acid-resistant liner, and acid stirring rod into the inner cylinder, close the test cylinder cover, tighten the wing nut, seal the cover, and then slowly submerge the inner cylinder in the water.

Insert the temperature sensor into the socket on the tank cover and connect it to the controller. Connect all other plugs to the corresponding sockets on the controller. Connect the power supply and check the grounding for reliability. Turn on the controller power switch.

Set the operating temperature of the thermostat unit to 20±0.1℃ and start the unit. Turn on the water pump. When the water temperature in the tank exceeds 20.1℃, the cooling water pump will supply cold water to exchange with the water in the tank. Stop when the temperature drops slightly below 20℃; the system will automatically maintain a constant water temperature.

Loosen the locking handle on the crossbeam. Rotate the crossbeam to a position where the main shaft and the acid stirring rod are on the same axis. Loosen the chuck, lift the stirring rod upwards and insert it into the chuck. Adjust the height of the acid stirring rod and tighten the chuck. Fine-tune the crossbeam angle to ensure the acid stirring rod is concentric with the hole on the cylinder cover. Lock the locking handle on the crossbeam. Install the Beckman differential thermometer and the loading funnel.

The test should be performed according to the relevant procedures specified in the national standard GB/T12959-2008 "Determination of Heat of Hydration of Cement (Heat of Solution Method)".

After the test, first shut down each component one by one, then turn off the main power switch. Unplug the power cord, then remove the Beckman differential thermometer, loading funnel, acid stirring rod, acid-resistant liner, etc., clean them thoroughly, and store them properly for future use. After closing the inner test cylinder, place it under the cylinder base and close the movable cover of the water tank. Turn off the thermostat.

V. Precautions for the SN2025-ACC004 Cement Hydration Heat Tester

Do not operate the test apparatus with the power supply on when the water tank is empty to prevent accidents.

Before adding water to the water tank, ensure the inner test cylinder is sealed and placed at the bottom of the cylinder base to prevent overflow when the overflow pipe cannot drain the water after filling the tank.

Handle the acid stirring rod carefully when loading and unloading it from the spindle chuck to prevent it from falling into the vacuum bottle and damaging it.

The part of the Beckman thermometer inserted into the acid solution and the surface of the cork stopper should be evenly coated with an acid-resistant coating such as paraffin wax. Before the test, the acid-resistant coating should be carefully checked to ensure it is intact.