Endothermic Mechanism in Cement-Based Fireproof Mixtures: A High-Temperature Guardian

In the construction industry, fire safety is a paramount concern. Cement-based fireproof mixtures have emerged as a pivotal solution, offering robust protection against high-temperature scenarios. A key feature of these mixtures is their ability to undergo endothermic reactions at elevated temperatures, effectively reducing surface temperatures and enhancing structural integrity during fires.​

Understanding the Endothermic Mechanism

Cement-based fireproof mixtures are engineered to absorb significant amounts of heat through endothermic reactions, thereby mitigating temperature rise and delaying structural degradation.​

Dehydration of Hydrated Compounds

At temperatures above 100°C, hydrated compounds such as calcium silicate hydrate (C-S-H) and calcium hydroxide (portlandite) begin to dehydrate. This dehydration process is endothermic, absorbing heat and thus reducing the temperature of the material's surface. For instance, the decomposition of calcium hydroxide occurs around 450–550°C, consuming thermal energy and releasing water vapor, which can further aid in cooling .​

Phase Transitions and Chemical Reactions

Certain aggregates within the cement matrix, such as quartz, undergo phase transitions at high temperatures. Quartz transforms from alpha to beta phase at approximately 573°C, a process that absorbs heat and contributes to the endothermic behavior of the mixture .

Advantages in Fire Protection

The endothermic properties of cement-based fireproof mixtures confer several benefits:​

• Temperature Regulation: By absorbing heat, these mixtures slow down the temperature rise, providing critical time for evacuation and firefighting efforts.​

• Structural Integrity: The delayed temperature increase helps maintain the structural integrity of buildings during fires, reducing the risk of collapse.​

• Environmental Safety: Unlike some fireproofing materials, cement-based mixtures do not release toxic fumes when exposed to high temperatures, ensuring safer conditions for occupants and first responders.​

Applications in Construction

Cement-based fireproof mixtures are versatile and can be applied in various construction scenarios:​

• High-Rise Buildings: Enhancing the fire resistance of structural elements to meet stringent safety codes.​

• Tunnels and Subways: Providing critical fire protection in enclosed spaces where evacuation is challenging.​

• Industrial Facilities: Safeguarding structures that are at higher risk of fire due to the nature of operations.​

Environmental Considerations

Beyond fire protection, cement-based fireproof mixtures align with sustainable construction practices:​

• Low Emissions: Their production and application result in minimal volatile organic compound (VOC) emissions.​

• Recyclability: Post-use, these materials can often be recycled or repurposed, reducing construction waste.​

Conclusion

The endothermic mechanism inherent in cement-based fireproof mixtures plays a crucial role in enhancing fire safety in modern construction. By absorbing heat and delaying temperature escalation, these materials provide a vital line of defense against fire hazards, ensuring the safety of structures and their occupants. Their integration into building practices reflects a commitment to safety, durability, and environmental responsibility.

Lior Lee

Email: [email protected]