Quantifying Passive Fire Protection Effectiveness in High-Rire Buildings

Thesis Abstract

This study addresses the critical question of how effectively passive fire protection (PFP) measures mitigate heat and flame transfer in high-rise buildings under real-world fire scenarios, where existing design guidance often relies on conservative assumptions and limited field verification. The problem stems from variability in PFP materials, installation quality, and occupancy patterns, which collectively influence compartmentalization performance, fire growth, and tenability timelines. The aim is to quantify PFP effectiveness in high-rise envelopes and structural assemblies, translating qualitative safety intent into empirically verifiable metrics. Specific objectives include (1) evaluating the thermal and structural performance of representative PFP assemblies under standardized fire exposure, (2) identifying the influence of installation quality and aging on PFP integrity, (3) developing a statistical model linking PFP attributes to time-to-failure indicators, and (4) proposing an evidence-based framework for performance-based occupancy limits and maintenance regimes. The study adopts a mixed-methods, multi-site empirical design grounded in performance-based fire safety theory and the framework of risk-informed decision making. The population comprises high-rise residential and office buildings constructed within the last two decades in three metropolitan regions, with a targeted sample of 24 buildings that have undergone recent PFP refurbishment or assessment. A stratified random sample yields 12 buildings with full-scale fire-test data and 12 with detailed post-fire or quasi-fire incident records. Data collection instruments include (a) full-scale furnace and room fire tests on representative wall, slab, and envelope assemblies to measure time to structural exposure, peak temperatures, and residual integrity, (b) non-destructive evaluation (NDE) techniques for PFP moisture content, bond shear strength, and delamination, (c) structured surveys and checklists documenting installation quality, material specifications, and maintenance history, and (d) fire incident reports and heat-release-rate data from building management systems. Kolmogorov–Smirnov tests, descriptive statistics, and reliability analyses quantify data distributions, while multiple regression and mixed-effects models identify predictors of PFP performance. A Bayesian hierarchical approach will integrate laboratory results with field observations to estimate probability distributions of protection factors under varying exposure scenarios. The theoretical underpinning draws on compartment fire dynamics, heat transfer theory, and the Protection-Integrity-Longevity (PIL) model, augmented by the Theory of Planned Behavior to account for installation and maintenance practices as determinants of PFP effectiveness. The empirical model will be validated against independent incident data from two recent fires with documented PFP performance outcomes. Key expected findings include (i) quantified reductions in heat flux and time-to-exceed temperatures attributable to specific PFP systems (e.g., cementitious boards, spray-applied intumescent coatings) across common construction assemblies; (ii) evidence of how installation quality, substrate compatibility, and aging degrade PFP performance, with measurable thresholds for acceptable performance margins; (iii) a robust predictive model linking material properties, installation fidelity, and maintenance schedules to protection factors and compartment stability; and (iv) a decision-support framework enabling designers and facilities managers to calibrate maintenance intervals and occupancy limits based on probabilistic PFP performance. The study contributes to knowledge by providing transferable, empirically derived performance indicators for PFP effectiveness in high-rise contexts, integrating laboratory and field data, and delivering a probabilistic framework for reliability-based design and maintenance planning. Practical implications include refined performance-based design criteria, improved inspection protocols, and policy recommendations for building codes to accommodate conditional occupancy strategies aligned with quantified PFP reliability. The final chapter discusses limitations related to data heterogeneity and regional fire regimes, suggesting avenues for expanding the database and incorporating emerging PFP technologies. Recommendations emphasize standardized post-installation quality assurance, routine non-destructive testing, and the establishment of building-level PFP performance registries to support continuous learning and risk reduction in high-rise fire safety.