The aesthetic aspect is one of the most important things in the design of buildings. The use of an Aluminum Composite Panel (ACP) to support that aspect is often found in various buildings, especially on the outside of the building (facade). But in reality, in the form of supporting this aspect, the ACP material has a very high risk of massive fires. This is evidenced in various massive fire incidents such as Grenfell Tower in London, and the Lacrosse Building in Docklands Victoria.
What is ACP?
ACP is generally composed of a composite material in the form of aluminum layered with a core material in the form of polyethylene (PE) or polyurethane (PU) in between. In some countries in Europe, Australia, and others the use of ACP with a core composition exceeding 30% has been prohibited. If the composition of the polymer core material in the ACP arrangement is more than 30%, this material will be very vulnerable to the risk of fire due to the low melting point of aluminum, so the potential for fire propagation can occur from one panel to another. Therefore, ACP can be susceptible to fire and some are fire retardant (resistant to fire). The types of cores that are more resistant to fire, include mineral materials; Aluminum Hydroxide (ATH), and Hydromagnesite (HM).
Based on Law No. 28 of 2002 and DKI Regional Government Regulation No. 7 of 2010, it is stated that the construction of buildings for offices, apartments, and high-rise flats must use a fire-resistant construction material. As for knowing the level of resistance of ACP material to fire, there are various types of fire rating tests according to the international standards, such as standards from Australia (USA) which are tests for small and large scale standards, (EN) the European Classification Test, and others including BS8414, ISO 13785 Part 2, NFPA 285 full-scale facade test.
ACP Specifications (Source: Seven Indonesia, one of ACP's leading brands in Indonesia)
The number of building construction in Indonesia has been rapidly increased over the last few decades, and it can be seen that the use of ACP also increasing, especially in the facade of the building. As a lightweight material, ACP is also easy to modify according to design needs, and its durability is also quite strong against water and in various kinds of weather. In addition, ACP is also often used in various parts of the interior of the building. Even so, ACP composite materials have the ability to easily burn and spread fire in buildings.
The combustibility of façade materials can be exacerbated by the presence of an air gap between the façade and the building itself. The air gap often makes it easier for fire to spread throughout the surface of the combustible fuel and at the same time restricts firefighters’ access to the fire. The chimney effect can also occur when the façade system used creates an internal return effect as can be found on balconies or vertical intrusions, thus, this often causes a reflection of heat from the burning material to other surfaces.
In addition, gaps between floors are often found in buildings specifically in the curtain wall section. The gaps generally should be filled with fire-stopping material during construction. However, due to a natural expansion and contraction of the building caused by thermal movement, the gap re-emerges and usually is hard to carry out inspection or maintenance. Thus, this poses a risk of fire spreading from one floor to another which can then be exacerbated by the use of combustible wall elements such as ACP.
The composite materials in ACP have led to a fire risk due to its constituent materials. The risks can result in different fire characteristics depending on:
Type of installation and sealant
ACP specific functions
Appropriateness of the fire protection system in buildings
Therefore, to reduce the risk, it is important to understand the specifications of the ACP material itself:
Confirm the detailed specifications (especially the type of the building material and the fire resistance level) of the ACP products to be installed
Understand the regulations and standards for the appropriate installations of ACP
Ensure that the product is properly installed according to the manufacturer’s recommended procedures
Request a professional assistant (Risk Engineer/Fire Engineer) to be able to assess and provide recommendations on activities above as compliance with the existing regulations, practical guidelines, and standards.
Writer: Jeihan Kartika - Fire Engineer Ignis Fire & Risk