The fire resistance of anchors refers to their ability to maintain their load-bearing and functional capacity for a given time under conditions of exposure to high temperatures, such as in the event of a fire. This resistance is evaluated through standardized tests that simulate fire conditions, expressed as a function of time (R30, R60, R90, R120 minutes, etc.).
The functions of anchorage resistance under fire exposure are as follows:
- Structural integrity:
Anchorages, as an integral part of a structure, must maintain their load-bearing capacity during a fire, preventing the collapse of the structure.
- Safety of people:
The fire resistance of anchors helps to ensure the safety of people, allowing evacuation and intervention of emergency services in case of fire.
- Prevention of fire spread:
Anchorages, especially in walls and ceilings, can help to prevent the spread of fire through the structure by maintaining the structural stability of these elements in the presence of fire for a certain period of time.
- No fire spread:
Anchorages do not contribute to the spread of fire and are therefore classified as A1 according to EN 13501-1.
The evaluation of the anchors is carried out by means of real fire tests in accordance with EN 1363-1 ‘Fire resistance tests’, which simulates the evolution of temperature over time in the event of a standard fire.
The anchors are subjected to different tensile loads, which will fail with the time of exposure to fire: the higher the load, the shorter the duration of exposure to fire.
Finally, fire exposure resistance values are obtained for standardized times of 30, 60, 90 and 120 minutes. However, due to the characteristics of the steel with which the anchors are manufactured, the mechanical resistance of an anchor exposed to fire is considerably lower than its resistance to static loads.
The anchors approved for exposure to fire are the following:
| ETA | Product | Version |
| 12/0397 | MTP wedge anchor | MTP. MTP-AT, MTP-G, MTP-X, MTP-A4 |
| 14/0068 | Drop in anchor | HEHO, HECLO, HEHC, HEA4, HEC4 |
| 18/1108 | Heavy duty anchor | SLPT, SLPC, SLPE |
| 20/0046 | Screw andhor | THE, THA, THP, THT, TFE, TFA, TFP, TFT, TFS, TFF |
| 24/0011 | Hammer anchor | NA-C, NA-E, NA-F, NA-R, NA-G |
| 24/0867 | Hybrid vinylester | MO-VH, MO-VHW |
In summary, the fire resistance of anchors is a crucial factor for structural safety and the protection of people in case of fire. The assessment of fire resistance, through standardised testing and compliance with norms and standards, ensures that anchorages can perform their function reliably during a fire.
