Analysis of fire performance of fire retardant lightweight cladding system using small-scale approach

Abstract

The recent fire incidents indicated that most of the fatalities occurred due to the rapid-fire spread by the aluminium composite panel (ACP) cladding systems on high-rise buildings. While typical full-scale fire tests may be performed to examine the flammability limitations of the building cladding, it is not feasible to analyse the flammability of the existing building cladding since the full-scale fire test requires a significant amount of test materials. Therefore, an alternative assessment framework is essential, which can use a small-scale test approach, whereas from the acquired data, the full-scale test scenario of the ACP cladding system can be simulated. Hence, the overall objective of this PhD study is to develop an assessment framework for ACP cladding systems using a small-scale test approach for evaluating the flammability of the common materials of the cladding system and the existing building cladding. The present thesis consists of four main parts. In the first part of the thesis, the flammability properties of the aluminium composite panels (ACPs) were thoroughly investigated using the Cone calorimeter. The study aimed to improve the test data consistency of reaction-to-fire properties, such as time to ignition (tign), peak heat release rate (pHRR), time to peak heat release rate (tpHRR), and total heat release (THR), which are considered critical parameters for fire assessment and regulatory screening of the ACP claddings used in buildings. Therefore, a new technique was developed for the current AS/NZS 3837 test protocol. In the second part, an alternative fire assessment screening method for cladding systems using a Cone calorimeter was developed. In the fire hazard assessment of aluminium composite cladding systems (ACPs), it was crucial to analyse the resultant flame behaviour of the panels and insulations used in the cladding system. In the third part of the study, a framework to extract the kinetics data of three ACPs (with 100%, 70%, and 7% polymer) was provided, and two insulations (extruded polystyrene and glass wool) were used in high-rise buildings. The fourth part of the thesis was devoted to coupling pyrolysis and combustion modelling using Fire Dynamics Simulator (FDS 6.7.9). Overall, a small-scale test approach was suggested as a framework for evaluating the ACP cladding system. Instead of directly analysing samples in full-scale tests, such as AS 5113, the approach advocated in this framework was based on quantified evidence from small-scale testing, which can serve as a technical tool for professional judgement in fire safety engineering. As a result, it is less expensive and takes less time to conduct a regulatory screening assessment of the fire performance of ACP cladding systems.

Date of Award	2023
Original language	English