1. Purpose

The HTYZF-2A cement autoclave complies with the national standard GB/T 750-2024. It is a special instrument used by cement production units, building materials research institutes, colleges and universities, and construction engineering quality inspection departments to determine the adverse effects of MgO (magnesium oxide) in cement on cement soundness.

Cement performance and its testing show that the content of MgO in cement clinker is mainly brought in by limestone raw materials. After clinker firing, most of the MgO exists in the form of periclase. Its structure is dense (commonly known as the dead-burned state) and is wrapped in clinker minerals, with an extremely slow reaction rate with water. It is generally believed that hydration continues even after 10 to 20 years or longer, generating Mg(OH)₂, which increases the solid-phase volume by 2.48 times. Local volume expansion produces great destructive stress inside the already hardened cement stone. Boiling the test cake at 100°C for 3 hours cannot cause a large amount of hydration of MgO, so the boiling method cannot test the cement soundness problem caused by periclase. High-temperature and high-pressure conditions can accelerate the hydration of periclase in clinker, so the unsoundness caused by the MgO content in clinker must be tested by the autoclave method.

• Technical Parameters